(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)

(19) World Intellectual Property Organization

International Bureau

(43) International Publication Date

26 May 2011 (26.05.2011)

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(51) International Patent Classification:

H01F 41/08 (2006.01) H01F 27/06 (2006.01)

H01F 27/02 (2006.01) H01F 30/16 (2006.01)

(21) International Application Number:

PCT/CA20 10/001845

(22) International Filing Date:

18 November 2010 (18.11.2010)

(25) Filing Language: English

(26) Publication Language: English

(30) Priority Data:

61/262,603 19 November 2009 (19.11.2009) US

(71) Applicant (for all designated States except US): HYDRO-QUEBEC [CA/CA]; 75, boul. Rell(~-Levesque

Ouest, 22e Etage, Montreal (Quebec) H2Z lA4 (CA).

(72) Inventors; and

(75) Inventors/Applicants (for US only): FRANCOEUR,

Bruno [CA/CA]; 971, Galilee, Beloeil (Quebec) BG

6Ml (CA). COUTURE, Pierre [CA/CA]; 1027, JeanBochart, Boucherville (Quebec) J4B 4A4 (CA).

(74) Agent: ROBIC; 1001, Square-Victoria, Bloc E - 8th

Floor, Montreal (Quebec) H2Z 2B7 (CA).

(81) Designated States (unless otherwise indicated, for every

kind ofnational protection available): AE, AG, AL, AM,

AO, AT, AU, AZ, BA, BB, BG, BH, BR, BW, BY, BZ,

CA,CH,CL,CN,CO, CR,CU, CZ,DE,DK,DM,DO,

DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT,

HN, HR, HU, 10, IL, IN, IS, JP, KE, KG, KM, KN, KP,

KR,KZ,LA,LC, LK,LR,LS, LT,LU, LY,MA,MD,

ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI,

NO, NZ, OM, PE, PG, PH, PL, PT, RO, RS, RU, SC, SD,

SE, SG, SK, SL, SM, ST, SV, SY, TH, n, TM, TN, TR,

TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW.

(84) Designated States (unless otherwise indicated, for every

kind ofregional protection available): ARIPO (BW, GH,

GM, KE, LR, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG,

ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, n,

TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK,

EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU,

LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK,

SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ,

GW, ML, MR, NE, SN, TD, TG).

Declarations under Rule 4.17:

as to applicant's entitlement to apply for and be granted

a patent (Rule 4.17(ii))

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(54) Title: ELECTRICAL TRANSFORMER ASSEMBLY

(57) Abstract: A support frame for an electrical transformer assembly,

comprising two loop-shaped parts, each loop-shaped part having a plurality of limbs, each limb having a peripheral recessed portion in which a primary electrical coil is mountable, and at least one secondary coil is mountable in piggyback on the primary electrical coil, one limb of each loopshaped part having a straight section. The frame also includes an adjustable attaching means for attaching one of the loop-shaped parts with

respect to the other loop-shaped part and adjusting a distance therebetween, so that only the straight sections are adjacent and form a central

leg, the central leg being for receiving a magnetic core distinct from the attaching means. The frame provides a means and a method to efficiently secure adjacent windings in a circular core transformer kernel.

FIGURE 36
WO 2011/060547 Al 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

Published:

- with international search report (Art. 21 (3))
WO 2011/060547

1

ELECTRICAL TRANSFORMER ASSEMBLY

FIELD OF THE INVENTION

PCT/CA2010/001845

The present invention relates to electrical transformers. More particularly, it relates to

distribution transformers for use in an electrical grid. More particularly, it also relates

,to single phase and three-phase distribution transformers.

BACKGROUND OF THE INVENTION

10

Electricity is produced, transmitted and distributed at an oscillating frequency of 50

or 60 Hz. Transformers are electrical apparatus used for modifying electricity

oscillating voltage and current. Because of the transformer, produced electricity can

be transformed and transmitted at high voltage and low current over long distances

with minimal joule loss before being transformed again to a lower voltage.

Distribution transformers are located at the end of the power lines to reduce the

voltage to usable values. Conventional distribution transformers comprise discrete

primary and secondary electrical conducting coils each made by winding multiple

loops of an electrical conductor while providing proper voltage insulation between

20 loops. Both primary and secondary coils enlace a core made of a ferromagnetic alloy

to create a path for a magnetic flux to circulate in a closed loop through both of said

coils. When an oscillating voltage is applied across the leads of the primary coil, it

induces a fluctuating magnetic flux in the core which, by reverse effect, induces back

a voltage across the lead terminals of the secondary coil. The ferromagnetic property

of the core allows an increase of the peak magnetic flux density induced by the coils

in order to reduce the coils loop size and therefore to reduce the size of the

transformer. The primary coil of a distribution transformer is on the high voltage side,

and the secondary coil is on the low voltage side. More than one secondary coil may

enlace the core to provide more than one low voltage.

30
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PCT/CA2010/001845

For households and small plants which account for the majority of loads, most

distribution transformers installed on the grid are single-phase units having a load

capacity mostly ranging from 10 to 200kVA. A typical primary voltage ranges

between 5 to 30 kV, and the secondary voltage ranges from 110 volts to up to 480

volts. The coils and the core form an interlaced assembly and are generally attached

in an enclosure filled with dielectric oil and which is equipped with feed-through

bushings for electrically connecting the leads (an insulated electrical conductor

connected to an electrical device) of the coils respectively to the power line and to

the load. For purpose of clarity, the term "transformer kernel" in this document will

10 refer to the coils and core assembly without the enclosure and accessories.

Two main types of transformer kernels are used for producing distribution

transformers: shell-type and core-type. In the shell-type design, the return flux paths

in the core are external to the enclosed coils. This is not the case for the core-type

design. A single phase shell-type distribution transformer has two cores respectively

enlaced around two distinct limbs of a single enclosed winding arrangement

comprising the primary and secondary coils. Alternately, a single phase core-type

transformer has two winding arrangements respectively enlaced around two limbs of

a single enclosed core. If the distribution transformer has two secondary coils,

20 typically for outputting 120/240 volts, then each secondary coil in the core-type

design must be subdivided and distributed among both winding arrangements to

ensure proper operation of the transformer under unbalanced loading; otherwise,

excessive tank heating will result from magnetic flux leakage. Doing so requires

making additional connections to link in series lead terminals from the sub-coils

composing each secondary coil. Shell-type transformers may operate correctly with

non-subdivided secondary coils. However, subdividing the secondary coils provides

a balanc;ed impedance for each 120-volt circuit, thus resulting in better voltage

regulation, minimizes circulating current in the secondary coils when connected in

parallel to supply one phase of a three-phase distributed voltage, and offers greater

30 coil reliability against lightning surges. Many manufacturers produce non-subdivided
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PCT/CA2010/001845

secondary coils in their shell-type distribution transformers to avoid the need for

additional connections, which requires bulky leads that significantly increase the

radial builds of the coils, often resulting in a requirement for a larger tank. As making

these connections is done manually, it is believed that the reliability can be

increased by avoiding them, which also reduces the cost of the transformer while still

providing acceptable voltage regulation and circulating current characteristics.

Choices of conductor materials for making the coils are limited to copper and

aluminum. Copper is more conductive than aluminum but weighs more. Insulating

10 materials mostly used are oil, kraft or aramid paper, cardboard, pressboard, varnish,

resin epoxy or reinforced epoxy. There are more available choices of magnetic

materials for making the core. Two family types of ferromagnetic alloys are mainly

used for making distribution transformer cores: grain-oriented silicon-steels and

amorphous-steels. Other alloys are available but are not cost effective and are

targeted for making motors, high frequency cores.

Grain-oriented silicon-steels are crystalline alloys formed in multiple interrupted

steps involving casting; annealing; quenching; rolling; decarburisation; and coating,

which come out into sheet thicknesses ranging from 0.23 to 0.35 mm and in different

20 grades. Their crystal grains are oriented in the sheet in order to provide uniaxial

magnetic anisotropy which is parallel to the rolling direction. Uniaxial anisotropy

reduces the transformer exciting current and core loss. The sheet must therefore be

positioned within the transformer core to have the rolled direction following the

circulating path of the induced magnetic flux. Prior to being used, silicon-steel sheets

must be heated in the form they will occupy in the core in order to relieve applied

bending stresses that impair on the magnetic properties and in order to retain the

shape. Heating of the steel is generally performed by annealing the preformed cores

in batch for a prolonged time in a furnace at a temperature above BOO°C.
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PCT/CA2010/001845

Amorphous-steels are non-crystalline alloys formed by casting the melted alloy on

the surface of a cooling wheel rotating at high speed, which will form a ribbon having

a thicknesses measuring from 0.02 to 0.05 mm. They are cheaper to form than

silicon-steels because of the single step casting process advantage. Even when

considering composition of both alloys, the price of as-cast amorphous steel ribbons

is cheaper than most popular grain-oriented silicon-steels. Amorphous-steels also

need to be heated to relieve internal residual stresses incurred during casting and

due to applied bending stresses. In addition, it is preferable to anneal amorphoussteels in a magnetic field to reduce the coercive force and to induce uniaxial

10 magnetic anisotropy which will be in parallel with the applied field. Conventionally,

the amorphous-steel ribbon is positioned within the transformer core to have its

longitudinal axis oriented following the circulating path of the induced magnetic flux.

Cores are conventionally batch annealed in a furnace at a temperature above 300°C

and with an applied magnetic field that follows the circulating path. Following

annealing, the amorphous-steel cores remain very sensitive to externally applied

stresses and the ribbon is rendered brittle. This makes amorphous-steels cores

difficult to handle and to assemble with the coils.

Internal power loss is inherent to all distribution transformers as they degrade their

20 efficiency and, efficiency of distribution transformers is an important aspect for

energy savings considerations. Internal power loss is generated in the transformer

when it is energized and it increases during loading. When only energized, an

induced fluctuating magnetic flux density is continuously present in the core. This

generates core loss in the ferromagnetic material associated with the magnetization

cycle and induces current loops within the metal alloy which create joule loss. At a

same level of fluctuating magnetic flux density, amorphous-steel cores produce

about one third of the core loss generated in silicon-steel cores. When a load is

added, load currents flowing in the conductors of the transformer coils produce

additional joule loss that is inversely proportional to the conductor size. At a same

30 size, a copper conductor will heat less than an aluminum conductor. The efficiency
WO 2011/060547

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PCT/CA2010/001845

of the transformer will be the ratio of the outputted power with respect to the total of

outputted power and internal power loss ( core and coils).

The distribution transformer power output capability is rated based on the

temperature rise above ambient of the coils. Immersing the transformer kernel in oil

contained in a smooth tank is the most economic means for providing efficient

cooling for keeping the coils temperature rise within permissible limits. Heat is

transferred from the hot transformer kernel to the oil, from the oil to the tank walls,

and then from the tank walls to the outside. For higher cooling capability, the wall

10 surface of the tank can be increased by corrugation or by means of either external

metal tubes welded into the sides of a tank or by external radiators attached to the

plain tank. Heat removal from the transformer kernel must also take into account the .

transfer of heat from the interior parts of the kernel. Heat can be transferred by

means of conduction, radiation, and convection. Of all three, convection is the most

important. Convection occurs by exposing hot surfaces to oil. Heat conducted from

the hot surface to the oil increases the fluid temperature and decreases its density.

This produces a circulating current as the lighter hot oil moves up in the tank to be

replaced by the cooler heavier fluid. The hot oil will be cooled by convecting along

the tank surface and will go back to the bottom. An increase of the heat transfer can

20 be gained by creating ducts on or within the kernel, mainly in the coils, with one

opening located near the bottom of the tank and another near the top for oil to flow

through. This will increase the oil convective current by a chimney effect (or stack

effect).

Proper choice of material and sizing of the transformer kernel will have an impact on

the transformer efficiency and rating. At equivalent transformer efficiencies, the

significant subtracted core loss gained over silicon-steel cores by using amorphoussteel cores can be transformed into additional joule loss within the coils by using

smaller conductor sizes. Doing so has the advantage of reducing transformer size

30 but will increase the joule loss density within the coils. This extra heat in the coils
WO 2011/060547

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PCT/CA2010/001845

may become a problem for evacuation if proper heat transfer means cannot be

provided from the interior of the coils to the oil.

Manufacturing of coils generally involves winding conductors and paper sheets on a

coil form using semi-automated or fully automated winding machines. The primary

and secondary coils have distinct numbers of coiled loops (winding turns). The

number of coiled loops of the primary coil will establish the peak magnetic flux in the

magnetic path of the core and the ratio of coiled loops of the primary coil over the

secondary coil will transform the input voltage to be outputted across the secondary

10 coil. The high voltage primary coil is normally made of several coiled loops arranged

in stacked rows (in the present document, a row is a number of objects arranged in a

"straight line") of a small conductor size covered by a varnish to insulate the side by

side stacked conductors. Preferably, a paper is added between adjacent rows to

provide an increased voltage withstanding capability. A spacer may be added in

between adjacent rows to provide cooling ducts for the coil. The low voltage

secondary coil having fewer turns, it becomes cheaper to wind a single width of a

bare conductor strip side by side with a wider paper strip. Exit leads must be

provided on the side of the coils at both ends of the coiled conductor to allow

connection between coils or to the feed-through bushings. The lead terminals are

20 normally welded to the ends of the coiled conductor, and are dressed with insulating

sleeves to ensure proper voltage isolation. Lead terminal installation, dressing and

connection with the bushing are mostly done manually, which increases transformer

costs.

Manufacturing of transformer cores involves adjoining or overlapping multiple

stacked flat ferromagnetic metal sheets (stacked-cut-core), or butting or overlapping

both ends of metal sheets that are bent into a closed loop shape (wound-cut-core),

or rolling up mUltiple turns of a continuous strip of metal sheet (rolled-up-uncut-core).

Cut cores have significant disadvantages over uncut cores. Firstly, manufacturing of

30 cut cores involve a lot of labour for cutting and forming, which increases transformer
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PCT/CA2010/001845

costs. Secondly, an increase in transformer exciting current and power loss are

associated with the presence of joints in the cores. Thirdly, cut cores lose the ability

to withstand hoop stresses and must therefore must be strapped and framed to

prevent the joints from opening. Of all types of cores, amorphous-steel wound-cutcores are the most expensive to produce, as they require, among other things: more

cutting steps; a special annealing furnace, and careful post handling.

Interlacing the electrical coils with the magnetic core is achieved either by manually

opening and reclosing the cut core around the pre-wound electrical coils, or by

10 winding the conductor of the electrical coils around a limb of the magnetic core (cut

or uncut), or inversely, by rolling up the metal strip around a limb of the coils to form

an uncut core. In the second and third cases, the coils to be wound or the uncut

core to be rolled up must be of circular shape. However, winding a continuous

conductor or metal strip around a limb is a smooth continuous task better adapted

for mass production in an automated industrial process. In a transformer having

circular coils, it is preferable to have a core limb of substantial cylindrical shape to

maximize the filling of the window of the coils in order to minimize the size of the

transformer. Therefore, different steel sheet widths must be stacked or wound to

create a core cross-section delimited by a circular boundary. Manufacturing of such

20 a core requires production of magnetic strips of different widths or material slitting

and more labour. On the other hand, a transformer having a circular core is

preferable as each conductor coiled loop can be arranged in the coils for all of them

to occupy most of the circular window of the core. Accordingly, the electrical

conductors are wound with a different number of coiled loops per row to fit within a

circular boundary. This can be done with the small electrical conductor commonly

constituting the high voltage primary coil. Generally, the primary coil is made with

circular conductors, but may also be made with rectangular conductors for a better

filling of the circular window. However, coiling and stacking up different widths of

rows of conductors to fit within a circular boundary, and Winding an insulating sheet

30 between adjacent rows is not obvious as conductors would tend to pack themselves
wo 2011/060547

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PCT/CA2010/001845

in a distorted manner and break the row, especially at the ends of each row near the

edges of the circular boundary, thereby creating difficulties in winding the insulating

sheet without tearing the edges. Therefore, ensuring organisation of coiled

conductors in stacked rows is critical as insulating sheets must be wound between

adjacent rows. As for the low voltage secondary conductors, they are generally

produced by simultaneously coiling a large bare conductor strip and an inSUlating

strip so that they pile up at each coiled loop in the middle portion of the circular area

with the rows of the conductors of the high voltage primary coil being distributed on

both sides. The assembled coil must then provide gaps between the edges of the

10 window of the coils to allow rotation of the core to be formed. Core lacing can be

made simple by using coils having an overall rectangular shape in order to provide a

rectangular window in the coils for rolling up a single width continuous ferromagnetic

metal strip. If necessary, a two-part rotating mandrel can be installed on the limb of

the coils as a support to easily roll up the strip.

A circular magnetic uncut core can be manufactured using a continuous single strip

width of a silicon-steel sheet or, of an amorphous-steel ribbon. For silicon-steel, the

complete core must first be rolled up on a second mandrel having the same diameter

as the one mounted on the coil limb and then annealed in a furnace. Once annealed,

20 the core must be unrolled and rolled up again on the electrical coils by inserting the

internal end of the strip first in order to put the strip back to its annealed

configuration. Given that conventional grain-oriented silicon-steel sheets show

significant stiffness, proper care must be taken to roll up the strip without bending the

material beyond its elastic limit. This makes the rolling up process more difficult and

the cores still need to be rolled up at first, annealed and handled separately, which

increase transformer costs. Annealed amorphous-steel circular uncut cores, on the

other hand, are built with a ribbon so thin that it can be severely bent during transfer

without reaching plastic deformation. Because the alloy remains sensitive to

externally applied stresses once annealed, tightly rolling up the ribbon increases

30 core loss and exciting currents. The best practice is to gently roll up the ribbon at a
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PCT/CA2010/001845

low tensile stress and to hold the finished core in place without adding significant

stresses with the framing structure. However, when the ribbon is rolled up at low

tensile stress, the formed core has no self structural integrity and the ribbon can

easily telescope if allowed to slide at one end. If the core axis is positioned vertically,

a supporting base is required. Also, because amorphous steel gets very brittle

following the furnace annealing treatment, unrolling and rolling up again is not

obvious. The method of unrolling, transferring and rolling up on another mandrel of a

ribbon from a furnace annealed ferromagnetic amorphous steel circular core has

been considered in US patent 4668309 and in many articles such as: "Induction

10 Accelerator Development for Heavy Ion Fusion", L.L. Reginato, IEEE Proceedings of

the 1993 Particle Accelerator Conference, vol. 1, p. 656 - 660, and : "Exciting New

Coating For Amorphous Glass Pulse Cores", RR Wood, IEEE 1999 12th

International Pulsed Power Conference, vol. 1, p. 393 - 396, and: "Induction Core

Alloys for Heavy-ion Inertial Fusion-energy Accelerators", A. W. Molvik, The

American Physical Society, Physical Review Special Topics - Accelerators and

Beams, vol. 5, 080401, 2002. From these prior art analyses, this method is believed

to be impractical as the ribbon tends to break too often during the transfer because

of its severe brittleness.

20 Another important aspect of a distribution transformer kernel is its ability to withstand

a short-circuit fault at the output of the secondary coil. During short-circuit conditions,

repulsive forces are generated between the primary and secondary coils. These

repulsive forces act on the coils in a way that they want to adopt a circular shape.

These forces will not impair on the structural integrity of the coils if they are already

made in a circular shape or, they can be sufficiently alleviated using elliptical shape

coils but this would require winding a series of strips having different widths which

will increase transformer cost as stated above. A core formed by rolling up a single

width steel strip will have a rectangular cross-section. Therefore, the coils must have

4 straight limbs delimiting a rectangUlar window for the core rectangular cross30 section to pass through. Conductors and paper forming rectangular coils lack the self
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PCT/CA2010/001845

structural integrity required to withstand the repulsive forces. Strong inward forces

will appear at each corner of the coils, which may cause the insulation at the corners

to fail if no adequate support is provided at the corners. Support at the corner may

be provided if the coils are firmly leaning against the core. A silicon-steel circular

core may be strong enough to sustain the inward forces on its corners, but this is not

possible for an amorphous steel circular core having poor structural integrity and

which reacts negatively to applied stresses as stated above. Coiling a bandage

around the coils or impregnating the coils in resin will improve the mechanical

strength to a certain extent. Proper self mechanical strength can be obtained by

10 encapsulating the coils in a casting resin to provide external reinforcing structure.

However, care must be ta.ken to e!"1sure that no bubbles are trapped during the

casting to avoid a corona discharge. There is also a risk of de-lamination between

the conductors/paper and the resin. Furthermore, cooling of the coils is made more

difficult.

Once a transformer kernel is completely assembled, means must be provided to

attach and secure the kernel in the enclosure. Conventional silicon-steel distribution

transformers are solidly fixed to the enclosure via the core. The practice is to use the

core as a support for the coils and then to clamp and secure the core in the

20 enclosure with a frame. This method is not suitable for amorphous-steel distribution

transformers and attaching the kernel via the coils is impractical. A best practice for

amorphous-steel distribution transformers is to have a frame for supporting both the

coils and the core without stressing them too much.

The US patent 5387894 discloses a core-type distribution transformer comprising a

circular core made by rolling up a continuous strip of ferromagnetic material on a

mandrel located around the cylindrical shape of two adjacent windings having a limb

of semi-circular cross section. The ferromagnetic strip can be an amorphous steel

strip which was first rolled up on a mandrel and then annealed under magnetic

30 saturation before being unrolled and rolled up again around the coils. However, the
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PCT/CA2010/001845

document does not discuss the embrittlement of the amorphous steel strip occurring

after core annealing and the difficulty to transfer a brittle amorphous-steel strip and,

does not teach how to provide support to the formed amorphous steel core.

Additionally, no teaching is provided on how to efficiently coil stacked up rows of

conductors of different widths and to wind an insulating sheet between adjacent rows

of conductors within a circular boundary. Additionally, no teaching is provided on

how to make, locate and connect the conductor lead terminals exiting from the coils.

Additionally, no means are provided to secure the adjacent windings and to secure

the transformer kernel into the tank. Additionally, no mechanical structural means

10 are provided to the coils to adequately sustain short-circuit mechanical forces at the

corners of the rectangular coils as the document alleviates the problem by making

these corners of the coils curved in an elliptical configuration. Finally, the document

does not teach how to provide cooling means to transfer the heat generated in the

conductors outside of the coils, especially when using an amorphous steel core

where such heat is more intense and is being generated in smaller coils for a given

transformer efficiency.

SUMMARY OF THE INVENTION

20 Accordingly, it is an object of the present invention to proVide methods and

apparatus to overcome at least one drawback of the prior art.

According to the present invention, there is provided a support frame for an electrical

transformer assembly, comprising:

-two loop-shaped parts, each loop-shaped part having a plurality of limbs,

each limb having a peripheral recessed portion in which a primary electrical coil is

mountable, and at least one secondary coil is mountable in piggyback on said

primary electrical coil, one limb of each loop-shaped part having a straight section;

and
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PCT/CA2010/001845

-an adjustable attaching means for attaching one of the loop-shaped parts

with respect to the other loop-shaped part and adjusting a distance therebetween, so

that only the straight sections are adjacent and form a central leg, the central leg

being for receiving a magnetic core distinct from the attaching means.

Preferably, the loop-shaped parts are made of a material selected from the group

comprising fibreglass, epoxy, paper, cardboard, wood and wood composites.

Preferably, the support frame further comprises securing means for securing the

10 loop-shaped parts to a transformer tank.

Preferably, according to a first embodiment, the securing means comprises:

-a base frame;

-first fixing means for fixing a bottom portion of the loop-shaped parts to the

base frame; and

-second fixing means for fixing the base frame to the transformer tank.

Preferably, according to another embodiment, the securing means comprises:

-a base frame;

20 -first fixing means for fixing a top portion of the loop-shaped parts to the base

frame; and

-second fixing means for fixing the base frame to the transformer tank.

Preferably, the securing means comprises alignment means for aligning the loopshaped parts with respect to the base frame.

Preferably, the support frame further comprises handling means located on a top

portion of the loop-shaped parts for handling and displacing the support frame from

one location to another.

30
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PCT/CA2010/001845

Preferably, according to another embodiment, the securing means comprises:

-a base frame;

-first fixing means for fixing the handling means of the loop-shaped parts to

the base frame; and

-second fixing means for fixing the base frame to the transformer tank.

Preferably, a selected one of said plurality of limbs other than those forming the

central leg further provides channels for conducting fluids adjacently and

transversely to the coils, each of the channels having one inlet on one side of said

10 one limb and one outlet on the other side of said one limb.

Preferably, the channels form an angle with respect to the horizontal to produce a

chimney effect in the fluids.

Preferably, the support frame further comprises a first chimney for enclosing the

inputs of the channels, the first chimney having a closed top and an open bottom,

. and a second chimney for enclosing the outputs of the channels, the second

chimney having a closed bottom and an open top, to produce, by means of the first

chimney and the second chimney, a chimney effect in the fluids.

20

Preferably, in one embodiment of the invention, the channels are formed by

transversal grooves in the recessed portion of the loop-shaped parts.

Preferably, in another embodiment of the invention, the channels are delimited by

insulating spacers positioned between adjacent rows of coils once mounted on the

loop-shaped parts.

Preferably, one of the loop-shaped parts is positionable with respect to the other

loop-shaped part by the adjustable attaching means such that the loop-shaped parts

30 are selectively separated by a first spacing distance and a second spacing distance,
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PCT/CA2010/001845

said second spacing distance being greater than the first spacing distance, the

support frame further comprising a mandrel surrounding the central leg, said

mandrel being sized to rotate freely around the central leg with the loop-shaped

parts separated by said first spacing distance and said mandrel being inhibited from

rotating around the central leg with the loop-shaped parts separated by said second

spacing distance.

Preferably, the mandrel is made from an insulating material selected from the group

comprising fibreglass, epoxy, paper, cardboard, wood and wood composites.

10

Preferably, the mandrel comprises interlockable first and second half portions.

Preferably, the mandrel further comprises opposite flanges at extremities thereof.

Preferably, the support frame further comprises at least one bracing member

mountable on an external surface of at least one of said limbs other than those

forming the central leg for securing the coils, once mounted, in position within the

loop-shaped parts.

20 Preferably, the at least one bracing member provides channels for conducting fluids

adjacently to the coils, each of the channels provided by said at least one bracing

member having an inlet and an outlet for allowing circulation by a chimney effect.

According to the present invention, there is also provided a loop-shaped part of a

support frame of an electrical transformer assembly, comprising:

-a plurality of limbs on which a primary electrical coil and at least one

secondary electrical coil are mountable, each limb having a peripheral recessed

portion in which the primary electrical coil is mountable, and said at least one

secondary coil being mountable in piggyback on said primary electrical coil, one limb
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PCT/CA2010/001845

of the loop-shaped part having a straight section, the peripheral recessed portion

comprising:

-a base portion for supporting said primary electrical coil;

-slanting sidewall portions extending from both sides of said base

portion, said slanting portions comprising a plurality of steps allowing a

stacking of rows of conductors and insulating layers of the primary

electrical coil.

Preferably, a height of a step in a corner between adjacent perpendicular limbs is

10 gradually reduced.

Preferably, one of said plurality of limbs further provides channels for conducting

fluids adjacently and transversely to the coils, each of the channels having one inlet

on one side of the loop-shaped part and one outlet on the other side of the loopshaped part and wherein a height of a step along a limb is increased by a length to

accommodate said inlet and outlet.

Preferably, one of said plurality of limbs further provides an tap input opening on one

side of the loop-shaped part, allowing connection of a tap to the coils, once mounted,

20 and wherein a height of a step along a limb is increased by a length to accommodate

said tap input opening.

Preferably, predetermined steps are formed for bridging a last coil loop of a row with

a first coil loop on an adjacent row.

Preferably, the bridging is performed at corners of perpendicular limbs.

Preferably, the loop shaped part comprises interlockable first and second half

portions.

30
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PCT/CA2010/001845

Preferably, one of said plurality of limbs further provides channels for conducting

fluids adjacently and transversely to the coils, each of the channels having one inlet

on one side of the loop-shaped part and one outlet on the other side of the loopshaped part, and wherein the channels are formed by transversal grooves traversing

the base portion and at least one of the slanting sidewall portions.

Preferably, a port fluidly connects the inlets to the transversal grooves traversing the

base portion.

10 Preferably, an inner surface of the loop-shaped part at the limb having the straight

section is SUbstantially semi-cylindrical and an inner surface of the loop-shaped part

at the limbs perpendicular to said limb having the straight section is flat.

Preferably, a radius of curvature of the inner surface that is substantially semicylindrical is smaller than an inner radius ota cylindrical core mountable around said

loop-shaped part.

According to the present invention, there is also provided an electrical coil assembly

comprising an electrical coil and a frame onto which the coil is wound, made of an

20 electrical conductor strip having a first end and a second end, at least one of the

ends being folded over itself along a first fold line according to an angle between 15

and 75 degrees such that said one end extends transversally with respect to a plane

where the coil lies to provide a connection lead.

Preferably, in one embodiment of the invention, the angle is 45 degrees.

Preferably, one end folded over itself is further folded along a second fold line

parallel to a longitudinal axis of the strip.
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PCT/CA2010/001845

Preferably, the electrical coil assembly is used in combination with an electrical

transformer core assembly which comprises a support frame comprising a loopshaped part, said loop-shaped part comprising a plurality of limbs and first and

second opposite sidewalls, two of said plurality of limbs forming opposite top and

bottom straight sections, said coil assembly comprising:

-a primary electrical coil wound around said loop-shaped part, said primary

electrical coil comprising first and second primary terminals at opposite ends

of said primary coil, said first and second primary terminals extending from the

first sidewall of the loop-shaped part;

10 -a 'secondary electrical coil wound around the primary electrical coil, said

secondary electrical coil being made from a conductor strip and comprising

first and second secondary terminals at opposite first and second ends of said

secondary coil, the first secondary coil terminal being formed by folding the

first end of the strip over itself along a first 45 degree fold line with respect to

the first sidewall such that a first length of the strip extends perpendicularly

with respect to and from the second sidewall opposite the first sidewall from

which the first and second primary sub-coil terminals extend,

the second secondary terminal being formed by folding the second end of the

strip over itself along a second 45 degree fold line to form a first intermediate

20 fold and folding the second end of the strip over the first intermediate fold

along a third 45 degree fold line perpendicular to the second 45 degree fold

line such that a second length of the strip extends in parallel with and outside

said first and second sidewalls.

According to the present invention, there is also provided a method of assembling an

electrical transformer kernel assembly, comprising the steps of:

a) winding a primary electrical coil around a first loop-shaped part having a

peripheral recessed portion along its outer surface for receiving the primary electrical

coil, the first loop-shaped part having at least one straight section;
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b) winding a secondary electrical coil on piggyback on the primary electric coil

around the first loop-shaped part;

c) winding a primary electrical coil around a second loop-shaped part having a

peripheral recessed portion along its outer surface for receiving the primary electrical

coil, the second loop-shaped part having at least one straight section;

d) winding a secondary electrical coil on piggyback on the primary electric coil

around the second loop-shaped part;

e) attaching the first loop-shaped part with respect to the second loop-shaped

part so that only the straight sections are adjacent and form a central leg;

10 f) adjusting a distance between the first loop-shaped part and the second

looped shaped part to a first spacing distance;

g) installing a mandrel around said central leg, said mandrel being sized to rotate

freely around the central leg when the first loop-shaped part and the second looped

shaped part are spaced by said first spacing distance; and

h) winding a metallic ribbon around the central leg to form a magnetic core,

wherein the winding step h) is distinct from the attaching step e).

Preferably, the method further comprises the steps of:

i) adjusting the distance between the first loop-shaped part and the second

20 looped shaped part to a second spacing distance greater than the first spacing

distance, such that the mandrel is inhibited from rotating around the central leg; and

j) inserting spacer elements between the adjacent straight sections forming the

central leg.

Preferably, the method further comprises, during steps a) and c), the steps of:

aa) forming a plurality of conductor loops with the primary electrical coil at distinct

predetermined turn counts;

bb) individually twisting each of the conductor loops to form connection leads;

cc) inserting insulating sleeves between adjacent twisted conductor loops; and
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PCT/CA2010/001845

dd) bending said leads transversally with respect to the winding of the primary

electrical coil.

According to the present invention, there is also provided a system for assembling

an electrical transformer kernel assembly, comprising:

-a first winding system for winding a primary electrical coil around a first loopshaped part and second loop,..shaped part respectively, each loop-shaped part

having a peripheral recessed portion along its outer surface for receiving the

primary electrical coil, the first loop-shaped part and the second loop-shaped

10 part each having at least one straight section;

-a second winding system for winding a secondary electrical coil on piggyback

on the primary electric coil around the first loop-shaped part and the second

loop-shaped part respectively;

-an attaching system for attaching the first loop-shaped part with respect to

the second loop-shaped part by means of an adjustable attaching means, so

that only the straight sections are adjacent and form a central leg;

-a mandrel installation system for installing a mandrel around said central leg,

said mandrel being sized to rotate freely around the central leg when the first

loop-shaped part and the second looped shaped part are spaced by a first

20 spacing distance; and

-a third winding system for winding a metallic ribbon around the central leg to

form a magnetic core, the core being distinct from the adjustable attaching

means.

Preferably, the above method may be used to manufacture electrical transformer

kernel assemblies in series production.

Preferably, the present invention also provides a storage container for containing a

plurality of electrical transformer kernel assemblies assembled by the above30 described method.
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BRIEF DESCRIPTION OF THE DRAWINGS

PCT/CA2010/001845

Figure 1 is a schematic view of a transformer kernel comprising a circular core;

Figure 2 is a schematic view of a cut cross section showing rows of conductors of

one of the two coil arrangements in a supporting frame passing through the core

window;

10 Figure 3 is a schematic view of a cut cross section showing rows of conductors of

two coil arrangements in 9 supportin.g frame passing through the core window when

they are leaning back-to-backon each other;

Figure 4 is a schematic view of a cut cross section showing rows of conductors of

two coil arrangements in a supporting frame passing through the core window when

they are separated apart by spacers and leaning against the mandrel of the circular

core;

Figure 5 shows rows of conductors of a primary sub-coil arrangement in a supporting

20 frame according to a preferred embodiment;

Figure 6 shows rows of conductors of another primary sub-coil arrangement in

another supporting frame according to another preferred embodiment;

Figure 7 is a schematic electrical diagram of a coil arrangement of a core·type

transformer;

Figure 8 is the schematic view of Figure 4 wherein the lead connections shown in

Figure 7 are associated;

30
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Figure 9 is a schematic view of a cut cross section of a coil arrangement in a

supporting frame of a horizontal limb located outside of the core window;

Figure 10 is a schematic view of a cut cross section of a coil arrangement in a

supporting frame of a vertical limb located outside of the core window;

Figure 11 is a perspective view of a supporting frame according to a preferred

embodiment;

10 Figure 12 is a schematic drawing of two compressed rows of conductors in a corner

of the supporting frame of Figure 11;

Figure 13 is a perspective cropped view of the supporting frame shown in Figure 11

showing how to coil a conductor from one row to the next according to a preferred

embodiment;

Figure 14 is a perspective cropped view of the supporting frame providing space for

routing taps according to a preferred embodiment;

20 Figure 15 is a perspective view of a supporting frame provided with skewed ducts for

convecting oil to flow through according to a preferred embodiment;

Figure 16 is a perspective view of a supporting frame provided with horizontal ducts

for convecting oil to flow through according to another preferred embodiment;

Figure 17 is a cut view of a supporting frame shown in Figure 16;

Figure 18 is a perspective view of two supporting frames assembled back-to-back

and secured with attaching means;

30
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PCT/CA2010/001845

Figure 19 is a perspective view of two supporting frames assembled back-to-back

and secured to a base with attaching means at the lower portion of the frames

according to a preferred embodiment;

Figure 20 is a perspective view of two supporting frames assembled back-to-back

and secured to a base with attaching means to a base at the top portion of the

frames according to another preferred embodiment;

Figure 21 is a perspective view from to viewing angles of a base frame for receiving

10 two supporting frames assembled back-to-back;

Figure 22 is a perspective view of a two part assembly of a supporting frame;

Figure 23 is a schematic drawing of a system for winding conductors around a

supporting frame;

Figure 24 is a schematic drawing of a supporting frame showing a method for

making taps on the conductor coil during winding of said coil;

20 Figures 25 A to E' are schematic drawings of sequences involved for winding a

conductor strip to form a coil around the supporting frame according to a preferred

embodiment;

Figures 26 A to JI are schematic drawings of sequences involved for winding a

conductor strip to form a coil around the supporting frame according to another

preferred embodiment;

Figures 27 A to E are schematic drawings of sequences involved for assembling a

transformer kernel with a core and two coil arrangements, for making electrical
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PCT/CA2010/001845

connections between coils, and for locating a transformer kernel in a transformer

tank with electrical connections to the bushings;

Figure 28 is a schematic drawing showing a front view of the transformer kernel

shown in Figure 27 in a tank;

Figures 29 A and B are schematic drawings of an additional sequence involved for

winding a conductor strip to form a coil around the supporting frame according to

another preferred embodiment;

10

Figures 30 A to C are two front and perspective views respectively of a supporting

mandrel for rolling-up a magnetic strip to form a circular core;

Figure 31 is a perspective view showing two coil arrangements assembled back-toback and secured before installing the core mandrel;

Figure 32 is a perspective view showing the installation of the core mandrel around

the central leg of two coil arrangements assembled back-to-back and secured;

20 Figure 33 is a perspective view showing an installation and rotation of a core

mandrel around the central leg of two coil arrangements assembled back-to-back

and secured;

Figure 34 is a top view of a system for rolling up a magnetic strip around a mandrel

installed around the central leg of two coil arrangements assembled back-to-back

and secured;

Figure 35 is a top view of the system shown in Figure 34 showing an adjustment

procedure before the rolling up of a magnetic strip around a mandrel installed around

30 the central leg of two coil arrangements assembled back-to-back and secured;
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PCT/CA2010/001845

10

20

Figure 36 is a perspective view from a first angle showing a completed transformer

kernel assembly attached to a base on the bottom of an oval tank;

Figure 37 is a perspective view from a second angle showing a completed

transformer kernel assembly attached to a base frame on the bottom of an oval tank;

Figure 38 is a perspective view from a third angle showing a completed transformer

kernel assembly attached to a base frame;

Figure 39 is a perspective view from a third angle of a transformer kernel assembly

without the core and comprising bracing members to secure the coils on the

supporting frames;

Figure 40 is a perspective view showing a three-phase transformer kernel

comprising a series of back-to-back coil arrangements and three circular cores.

Figure 41 is a perspective view of a container used for storing and shipping multiple

transformer kernels;

Figure 42 includes two perspective views from to viewing angles of an oval

transformer tank assembly for enclosing a transformer kernel of the present

invention;

PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

Different preferred objects of the present invention will now be presented.
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PCT/CA2010/001845

Among all of the core and coil assembly methods for manufacturing distribution

transformer kernels as described above, it is believed that a distribution transformer

having a circular core made by rolling up a continuous single strip of an in-line

curved annealed amorphous-steel ribbon around pre-wound coils is the method

involving minimum discontinuous manufacturing steps, which can be better

automated for mass production and is of minimal cost. US patent application number

61/262,603 discloses a new system and method for treating an amorphous metallic

ribbon which is used to in-line anneal at low cost an amorphous-steel ribbon into a

10 curved shape, such annealed ribbon showing good ductility to efficiently allow its

rolling up to form a circular core. Furthermore, such an in-line curved annealed

amorphous-steel ribbon can be rolled up to form circular cores showing low core loss

and low exciting power at high magnetic induction levels from which distribution

transformer kernels can be manufactured. Such distribution transformer kernels are

small compared to conventional silicon-steel distribution transformer kernels at the

same level of efficiency. Using such in-line curved annealed ribbons eliminates the

breaking problem associated to unrolling and rolling up again the ribbon of furnace

annealed core which renders the manufacturing of circular-uncut core distribution

transformers possible and cost effective.

20

An object of the present invention is to provide a distribution transformer kernel

having a circular core made from rolling up an in-line-annealed amorphous-steel

ductile ribbon and not having the disadvantages and limitations associated to known·

configuration designs and manufacturing methods.

Another object of the present invention is to provide a distribution transformer kernel

having a circular core which can be massively manufactured at low cost.
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PCT/CA2010/001845

Accordingly, the present invention provides a method to efficiently coil and stack

different widths of rows of conductors and wind an insulating strip between adjacent

rows within a recess having a curved boundary.

Accordingly, the present invention also further provides means and a method to

efficiently secure adjacent windings in an amorphous steel circular core transformer

kernel.

Accordingly, the present invention also further provides a means to efficiently

10 support the coil and the core of a circular amorphous-steel core transformer kernel.

Accordingly, the present invention also further provides a transformer kernel which

can be efficiently enclosed and fixed in a small oval tank.

Accordingly, the present invention also further provides a means and a method to

pre-form and to dress the secondary coil lead terminals for making easy connection

between sub-coils and to the tank bushings.

Accordingly, the present invention also further provides a means and a method to

20 efficiently secure an amorphous steel circular core transformer kernel into a tank.

Accordingly, the present invention also further provides a means and a method to

efficiently remove heat generated within the coils of a circular amorphous-steel core

transformer kernel.

Accordingly, the present invention also further provides a means and a method to

efficiently sustain short-circuit forces in rectangular coils of a circular core

transformer kernel.
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PCT/CA2010/001845

Accordingly, the present invention also further provides a means and a method to

efficiently wind a conductor on a coil frame and to make, locate the lead terminals.

Accordingly, the present invention also further provides a means and a method to

efficiently roll up an amorphous steel strip to form a circular core around the coils of

a transformer kernel.

Accordingly, the present invention also further provides a means and a method to

allow rotation and immobilisation of a circular core mounted around a limb of a coil

10 arrangement.

Accordingly, the present invention also further provides a transformer kernel that can

be efficiently enclosed in an oval enclosure or tank.

Figure 1 displays the basic geometric configuration of a single phase circular-uncutcore core-type transformer kernel. It comprises one circular core 1 interweaved with

two rectangular coil arrangements 3. Preferably, the coil-core arrangement lies with

the circular core central axis in a vertical position. Each rectangular coil arrangement

3 comprises an inner primary sub-coil 5 and an outer secondary sub-coil 7. The two

20 rectangular coil arrangements 3 are positioned back-to-back to form a double coil

arrangement having one common central limb of circular shape around which the

magnetic circular core 1 is enlaced. Therefore, each coil arrangement 3 has a limb

with the cross section fitting within a half-disc.

Figure 2 shows a cut view of a limb from one of the two coil arrangements 3 passing

through the core window. It comprises a supporting frame 9 preferably made of a

mouldable dielectric reinforced material such as press board, epoxy, fibre reinforced

epoxy, fibre glass, composite material. The outer wall 11 of the supporting frame 9

has an arc shape. The inner walls 13 of the supporting frame 9 are arranged in a

30 series of steps 8 to provide a recess to accommodate the rows of small conductors
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PCT/CA2010/001845

15 of the primary sub-coil 5. Each conductor 15 represents one coiled loop of an

electrical coil, the first coiled loop being wound at the deepest part of the recess and

the last one being wound on top of the coil. The thickness along the inner walls 13

and the outer wall 11 is determined to provide proper dielectric insulation between

the core 1 and the primary sub-coil conductors 15. The conductors 15 from each

coiled loop of the primary sub-coil 5 are arranged in rows preferably separated by a

thin electrical insulating layer 17 of a material such as paper, epoxy coated paper or

poly-aramid to provide insulation between rows. Each conductor 15 is covered by a

thin electrical insulating coating, such as varnish, to provide proper electrical

10 insulation between adjacent conductors. The bottom center portion of the inner

recess walls 13 of the supporting frame 9 is flat and supports a first row of

conductors 15. Multiple rows of conductors 15 are then stacked, preferably

separated by a thin dielectric layer 17, to form the rows of sub-coil conductors. The

maximum number of arranged conductors in each row is determined by the

thickness along the inner walls 13 and the outer wall 11 which provides proper

dielectric insulation between the core 1 and the conductors 15. The steps 8 of the

inner walls 13 are aligned on both sides of the central bottom flat portion to

accommodate each additional row of conductors with the thin insulating layer 17

having the corresponding row width. Each thin insulating layer 17 of a row can be

20 produced by winding and stacking a few coiled loops of a thinner strip to limit the

overlapping thickness which is preferably located outside of the core window. The

height of each step 8 is equal to the sum of each row's height facing the step. On top

of the last row of conductors, there is a thicker electrical insulating row 19 preferably

made with several coiled loops of a thinner insulating strip such as a strip of paper,

epoxy coated paper or poly-aramid, and extending on each side over the supporting

frame. The junction between the thicker dielectric row 19 and the sides 21 of the

supporting frame 9 represents a tracking path yielding lower dielectric strength than

the dielectric strength in both materials. Therefore, a safe tracking distance is

provided between the top rows of conductors 15 and the edge of the supporting

30 frame outer wall 11. A conductor strip 27 adjoined to a thin insulating strip preferably
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PCT/CA2010/001845

made of paper, epoxy coated paper or poly-aramid, and which is slightly wider than

the conductor strip 27 is simultaneously coiled in piggyback over the thick insulating

row 19, each loop being made of one wide conductor strip. The width of the

conductor strip is chosen to keep a safe tracking distance with the edge of the

supporting frame outer wall 11. The portion of the supporting frame, the sub-coils

and the insulating row shown in Figure 2 are arranged to fit within a half-disc shape.

The arc shape of the outer wall 11 of the coil frame is chosen to have a radius

smaller or equal to the inner radius of the core supporting mandrel 31. The height

between the midpoint 36 on the arc shape of the outer wall 11 of the supporting

10 frame 9 and the midpoint 33 on top of the last coiled loop of the secondary coil is

slightly smaller than the inner radius of the core supporting mandrel 31 in order to

create a gap 35 between the limb and the inner wall of the mandrel 31 which

supports the core 1. This gap 35 allows the core 1 with the mandrel 31 to rotate

freely as shown by the arrow. With the supporting frame of the present invention,

loops of conductors can be efficiently coiled in stacked rows with coiled loops of an

insulating strip between adjacent rows.

Referring to Figure 3, there are shown two half-disc limbs of two coil arrangements

positioned back-to-back within the window opening of a circular core (the coil

20 portions outside of the core are not shown). The two back to back limbs are leaning

against each other in order to create the gap 35 which allows the mandrel 31 to

rotate freely in order to be able to roll up the amorphous in-line annealed alloy ribbon

on the mandrel to form the circular core 1.

Referring now to Figure 4, there is shown a zoomed view of the central portion of the

core with the two half-disc limbs of the two coil arrangements now separated by

insulated spacers 37. The half-disc limbs of the two coil arrangements are separated

apart and are immobilized by each leaning at their midpoint 36 against the inner wall

of the core mandrel 31. The insulated spacers 37 are placed between the two back30 to-back coil arrangements to maintain a gap and to create opening ducts 39 for oil to
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PCT/CA2010/001845

flow through in order to cool the conductors. Two openings 41 forming ducts on each

side of the secondary coil are also available for oil to flow through in order to cool the

coils. Preferably, the circular core lies in the transformer tank with its central axis in

vertical position to allow flow of convecting oil in the ducts by a chimney effect.

Preferably, entry and exit openings under and over the core-coil arrangement are

provided for the transformer kernel in the tank for the cooled oil to get in from under

and for the heated oil to get out from the top. Therefore, heat produced in the

conductors within the core windows can be efficiently extracted through the formed

cooling ducts.

10

Coiling. of the conductor in rows increasing in width as they are. stacked raises the

problem of having to route the coiled conductor from one roW to the next. Referring

to Figure 5, there is shown one preferred embodiment according to the present

invention of a supporting frame with a different arrangement of steps and a coiling

method. The first row of conductor is coiled from starting location 23 from the right

end of the first row to the left end and then, is switched to the next upper row as

shown by the curved arrow at the end of the row. The conductor is then coiled from

left end to the right end of the corresponding row and then, is switched to the next

upper row. This method of coiling requires a free passage way in the supporting

20 frame at the end of some rows in order to bring the conductor under the starting end

of the next upper wider row before the coiling of the conductor can start by then

bringing up the conductor to the new row level. When required, a narrow strip of

insulating material 28 can be added at the end of the row to provide a safe tracking

distance between the first coiled loop of a row and the last coiled loop of the next

upper row where the voltage between two conductors of adjacent coiled rows is

maximal.

Referring now to Figure 6, there is shown another preferred embodiment of the

present invention of a supporting frame with a different arrangement of steps not

30 requiring free passage ways in the supporting frame to route the coiled conductor
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PCT/CA2010/001845

from one row to the next. The first row of conductor is coiled from starting location 24

at the right end of the first row to the left end and then, is vertically switched to the

next upper row as shown by the curved arrow at the .end of the aligned row. The

conductor is then coiled from left end to the right end which extends beyond the

starting coiled location 24 and then, is vertically switched to the next upper row to be

coiled as shown by the curved arrow at the end of the extending row. When

required, a narrow strip of insulating material 28 can also be added at the end of the

row to provide a safe tracking distance between the first coiled loop of a row and the

last coiled loop of the next upper row where the voltage between two conductors of

10 adjacent coiled rows is maximal.

Figure 7 is an electrical schematic drawing showing the interconnection

arrangements between the sub-coils of a single phase transformer with two Low

Voltage outputs. The High Voltage primary coil 43 comprises two sub-coils HVa and

HVb connected in series. The two Low Voltage secondary coils 45, LV1 and LV2,

each comprise two sub-coils LV1a, LV2a and LV1b, LV2b connected in series.

Voltage points V1 to VB are indicative values of voltage at each lead terminal of a

coil. Typically, in a single phase transformer (like for a 14.4kV-120/240V), voltage

points V1 and V4 are connected to the electrical ground voltage reference, voltage

20 point V3 is the high voltage on the primary side, and voltage points V6, V8 are two

low voltages of the secondary outputs. In the schematic, V2, V5 and V7 are

intermediate voltage points between two sub-coils.

Referring to Figure 8, each sub-coil shown in Figure 7 is associated with a group of

loops of conductors. Each coil arrangement 3 comprises a high voltage sub-coil

(HVa or HVb), and two low voltage sub-coils (LV1a/LV2b or LV1b/LV2a), one from

each secondary coil. The distribution of the secondary sub-coils on both coil

arrangements 3 maintains an equilibrium in the flow of current in both coil

arrangements 3 in case of a load unbalance (interlaced secondary coils). In each

30 sub-coil shown in Figure 8, there are two leads at both ends of the sub-coil which are
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PCT/CA2010/001845

respectively routed to the first and last coiled loop of a conductor of the sub-coil.

Each lead connects to voltage points V1 to V8 of Figure 7. Preferably, each lead

exits the sub-coil at a location on one of the limbs located outside of the core

window. Also, attributing a voltage point to a lead of a primary sub-coil will impact on

the dielectric thickness of the coil frame between the primary sub-coil and the core

mandrel 31. Preferably, in Figure 8, the core mandrel 31 is made of an insulating

material and the core 1 is electrically connected to the transformer tank which is

connected to the ground voltage reference. Therefore, the dielectric thickness

between a primary sub-coil and the core includes the coil frame and the mandrel

10 thickness. The connections of the leads to voltage points V1 to V8 shown in Figure 8

represent a preferred embodiment.

Using the schematic of Figure 7 and referring to Figure 8: Preferably, the lead

extending from conductor loop 51 of the HVa sub-coil is connected to the point V3.

Since point V3 corresponds to the highest voltage, the dielectric portion of the

supporting frame at the location 47 which is facing the bottom row of HVa will

preferably have the maximum thickness. Next, the leads extending from conductor

loops 53 and 55 of the HVa and HVb sub-coils are connected to point V2. More than

one lead can be provided on the last coiled row of loops of conductors in sub-coils

20 HVa and HVb to allow connections to a tap selector for adjusting the voltage

outputted at the secondary coils by choosing which pair of leads from respective

sub-coils HVa and HVb will be connected to point V2. Since the voltage point V2 is

at about half of V3, the thickness of the insulation layer 19 between HVa and LV2b

sub-coils and between HVb and LV1 b sub-coils is set accordingly. Next, the lead

extending from conductor loop 57 of the HVb sub-coil is connected to point V1.

Since voltage point V1 is lower than V3, the dielectric portion of the supporting frame

at the location 49 which is facing the top row of HVb can be of smaller thickness

compared to region 47. With the primary coil arrangement of the present invention,

proper voltage insulation is provided between loops of conductors and the core, in

30 order to withstand high voltage impulse tests.
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PCT/CA2010/001845

Now, for the secondary sub-coils, preferably, the leads extending from conductor

loops 59 and 61 of LV2b and LV1b sub-coils are respectively connected to points V8

and V6. Next, the leads extending from conductor loops 67 and 65 of LV1a and

LV1 b sub-coils are connected to points V5 and are connecting these sub-coils in

series. Furthermore, the leads extending from conductor loops 69 and 63 of LV2a

and LV2b sub-coils are connected to points V7 and are also connecting these 5ubcoils in series. Finally, the leads extending from conductor loops 71 and 73 of LV2a

and LV1a sub-coils are connected to point V4. This way, the conductor of the last

10 outer coiled conductor loop of each coil arrangement 3 shown in Figure 1 will be at

the lowest voltage, as V4 is normally connected to the ground voltage reference (this

is generally the case for the 120/240V secondary coils of a distribution transformer).

In the case where the transformer only has one secondary coil, there will only be two

secondary sub-coils connected in series, with one secondary sub-coil per coil

arrangement 3. With the conductor arrangement of the present invention, proper

voltage insulation is provided to withstand high voltage impulse tests.

Referring now to Figure 9, a cross section of the top and bottom horizontal portions

of the two coil arrangements 3 that are located outside of the core window opening is

20 shown. The outline of the cross section for the supporting frame is not constrained

by the circular shape of the window opening. In Figure g, the wall of the supporting

frame g can be made thicker to assume a shape that suits best the requirement for

providing stronger mechanical structural support. However, there is an immediate

space limitation due to the presence of the core 1. For the top and bottom horizontal

portion of the coil arrangements shown in Figure 1, the bottom boundary 75 of the

supporting frame shown in Figure 9 is limited to a straight line to clear the flat

surface 76 of the circular core edges. For the lower horizontal portion of the coil

arrangement, the straight boundary can be efficiently used to create a flat surface for

supporting the core. Referring now to Figure 10, a cross section of the vertical

30 portions of the two coil arrangements 3 that is located outside of the core window
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PCT/CA2010/001845

opening is shown. The bottom portion of the supporting frame can also have a

straight boundary 72 or it can be extended to adopt a curved shape 77 as it needs to

clear the outer radius of the circular core 1. As for the side boundaries in Figure 9

and 10, there is no immediate space limitation. For the portion of the supporting

frame located outside the core window opening, preferably, the side boundaries 79

have a shape which increases the supporting frame thickness. In Figure 9 and 10,

the two side boundaries 79 are straight and parallel.

Figure 11 shows a perspective view of a supporting frame having limbs that were

10 extruded using the cross section outline shown in Figures 5, 9 and 10. The limb 87 is

extruded according to the outline of the cross section of Figure 5 and the limbs 83

and 85 are extruded according to the outline of the cross section shown in Figure 9.

As for the limb 89, it is extruded using the straight boundary 72 of Figure 10. For all

four limbs, the walls 13 of the recessed portion of the supporting frame are extruded

based on the configuration of steps 8 of Figure 5. All four limbs are preferably

straight in order to provide a rectangular window opening for passing the core. At

each corner, the outline of the supporting frame is an extrusion revolving around the

inner corner where the limbs are meeting to provide a series of steps arranged in a

curved shape 81 for a smooth transition of each conductor rows from limb to limb.

20 Overall, the shown supporting frame is an arrangement taking the form of mounted

U shaped beams outside the core windows and which provides strong structural

integrity for supporting the coils and the core. The strong structural integrity of the

supporting frame will efficiently withstand the strong short-circuit forces from hoop

stresses exerted by the rectangular shaped coils. To reduce weight without losing

structural integrity, openings (not shown) could be realized in predetermined regions

in the material. These openings could expose external sections of the primary coil to

oil in order to cool the conductors. The switching of the conductor loop 15 of the

primary sub-coil from one row to the next, the overlapping of each insulating layer 17

coiled over each row, and the output leads for the primary and secondary sub-coils
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are all located on one of the three limbs of the coil arrangement situated outside of

the core window opening.

When coiling the conductor 15 of a row over an insulating layer 17, the tensile stress

applied in the conductor during coiling exerts an inner pressure on the underneath

rows at each corner on the curved shape 81 of the supporting frame. Referring now

to Figure 12, if the primary sub-coil is coiled with a round conductor, the coiled

conductor will naturally position itself on the small recess appearing on the insulating

layer by deformation due to the void located between two side by side conductors of

10 the underneath row. Due to this deformation, the height between two conductors of

adjacent rows will be smaller by a E value which is dependant to the conductor coiled

tensile stress and to the reciprocal of the bending radius of the coiled conductor

when turning the corner. This E value will reach its maximum for each row at mid

point along the curved shape 81 in a corner as shown in Figure 12. Accordingly, the

step height 8 is gradually reduced from both ends of the curved shape 81 to reach a

minimum height reduced by an E value at mid point along the curved shape 81 in

each corner of the supporting frame. The E value for each step in the corners is

dependent on the number of rows facing the step, on the tensile stress applied when

coiling the conductor, and on the bending radius applied to the conductor when

20 turning the corner. This ensures proper filling of each row in the recess portion of the

supporting frame in accordance to the provided steps and allows efficient coiling of

the supporting frame.

Referring to Figure 13, the support frame further comprises free passage ways 97

between rows for allowing the last coiled conductor in a row, next to the edge of a

step 99, to switch to the upper row, next to the edge of the upper step 101, while

bending around the corner 118. To exit the two coil leads out of the supporting

frame, two holes 93 and 94 are perforated on one side of the supporting frame, one

hole aligned with the flat surface of the recessed portion to start the coiling the first
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row, and the other aligned with the last coiled row. Insulating tubes 95 and 96 can be

added to guide the coil leads away from the supporting frame so that an insulating

flexible sleeve can be slid on each lead and strapped around the exit tube for

increased insulation around the leads outside of the coil. Alternatively, the lead on

the last coiled row can exit between the coil frame edge 86 and the insulating layer

19 through insulating paper sleeves. Referring to Figure 14, the edges 86 on top of

the supporting frame could extend over the last row of conductors to provide a space

for the coil lead to exit. The supporting frame edge on the exit side would comprise

at least one transverse slot 108 for allowing the dressed lead to make its way out.

10 More slots can be provided if more than one dressed lead is required on the coil to

allow connections to a tap selector.

The secondary sub-coils 7 as shown in Figure 1 have significant outer surface

portions available for oil convection cooling within the transformer tank. This includes

the portion located within the core window opening. For the primary coils however,

the heat is evacuated via the secondary coil and the supporting frame. Further

cooling capacity of the primary coils can be added by introducing cooling ducts

between rows of conductors 15. Referring back to Figure 10, the supporting frame is

provided on each side with openings 103, 104 and transversal insulating spacers

20 105 inserted between two rows of conductors 15 to create opening ducts between

spacers for oil to flow through in order to cool the conductors. Figure 15 shows a

perspective view of the cooling ducts. The spacers 105 are added in the recessed

portion of limb 107 of the supporting frame and are skewed to create upward oil

circulating ducts. To make space for the spacers, the height of the steps 8 on both

sides of the spacers are increased. Two ramp-up spacers 113 and 114 could also be

used to smooth the elevation of the conductors. The spacers 105 being skewed, flow

of oil in the ducts is provoked by the chimney effect. The oil enters via the opening

103 and exits via the opening 104 on the other side of supporting frame. The

spacers 105 could also be placed horizontally as shown in Figure 16 and 17. In this

30 case, additional vertical ducts 109 and 111 are added on each side of the supporting
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frame to create the chimney effect. Each duct has an opening for oil to get in or to

get out. Oil entering from the bottom of the tank is guided up by the vertical duct 111,

enters in the openings 103, flows through the coil, flows through the openings 104

and is collected by the vertical duct 109 to exit at the top. The same vertical ducts

can be added with the skewed spacers to increase the chimney effect and therefore

the oil flow for better cooling. With the provided ducts, heat can be evacuated from

the conductors of the primary coil located in the core window opening, by using the

high thermal conductivity of the conductors themselves to carry the heat out to the

location of the ducts. In another preferred embodiment, additional cooling ducts can

10 be provided by transversely slotting the steps in the recessed portion of the

supporting frame from one opening 103 to the other side opening 104 to create

cooling ducts 106 as shown in Figures 10 and 11 that will allow flowing oil to cool the

inner surface of the primary sub-coil facing the recessed portion of the supporting

frame. Additionally, these duets 106 can be skewed to create upward oil circulating

ducts. Referring to Figures 9, 13 and 14, further cooling can be provided on the top

and bottom horizontal portions of the supporting frame by slotting only one side in

the steps from the flat bottom surface of the recessed portion of the supporting frame

up to an opening 110 and, by providing a horizontal opening 102 through the other

side, the opening 102 being aligned with the flat bottom surface of the recessed

20 portion. The slot 98 with both openings 102 and 110 will provide an upward cooling

duct to create a convecting flow of oil by chimney effect.

Referring back to Figure 11, the supporting frame of the present invention further

comprises protuberant portions 84 located at the top and bottom on each side of the

supporting frame, near the arc shaped limb 87. These protuberant portions 84

comprise an opening 88 perpendicularly aligned with the edge of the arc shaped

limb 87. Figure 18 shows two supporting frames assembled back to back with

adjusting attaching means such as insulated threaded rods 115, with insulated

washers 117 and nuts 119. Such adjusting attaching means are used to secure both

30 supporting frames together to form a unique rigid structure. Positioning the nuts on
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the rods allows adjustment of the distance between the two frames. Furthermore, the

supporting frame is provided with at least two protuberant portions 94 located on

each side to allow the assembled frames to lean on a flat base. Furthermore, the

supporting frame is equipped with at least two protuberant portions 90 located on

each side to provide bollards to ease lifting and handling of the assembly.

The supporting frame of the present invention comprises means to secure the back

to back supporting frames within a transformer tank. Referring to Figure 19, each

supporting frame comprises protuberant portions 117 located at the bottom on each

10 side of the supporting frame. These protuberant portions 117 comprise an opening

perpendicularly aligned with a base plane 121 for securing the assembled supporting

frames to the base with nuts screwed on a threaded elevated rods fixed on the base

plane. In another preferred embodiment shown in Figure 20, attaching straps 123

secure the supporting frame to the base plane by each having one end looping

around the bollard 90 and the other end being pulled and anchored with washers

and nuts to a threaded rod fixed at the base. These attaching means using straps

123 have the advantage of holding the supporting frames by pulling down their top

portions. Normally, the base plane is the inside bottom surface of a transformer tank

onto which the elevating threaded rods are fixed on by means of a weld. However, it

20 'may be difficult to provide a uniform flat surface for the supporting frames to

adequately lean on because the bottom surface of a tank may be slightly convex.

The present invention comprises as shown in Figure 21 a base frame 125 basically

constituted of metal angles cut and weld together to provide a rigid levelled surface

127 to support the frame assembly and openings 129 for holding bolts for anchoring

the support frame attaching means. The base frame also comprises nipples 131

formed under the base frame and which are used as welding points to secure the

base frame at the tank bottom. The base frame 125 is shown for both attaching

means in Figures 19 and 20. With the shown attaching and anchoring means, the

two back-to-back supporting frames form one rigid structure which is solidly secured

30 on the bottom of the tank. The two supporting frames offer the advantage of
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supporting the coils and the core in the tank without transmitting mechanical

stresses to them.

Referring now to Figure 22, there is shown a supporting frame made of a two part

assembly. Both parts 134 and 136 are mated together by inserting the male portion

133 of the first half supporting frame 134 into the female portion 135 of the second

half supporting frame 136. This mating junction provides a tracking path at least

three times superior to the insulating thickness near the junction once the two halves

are assembled. A proper binder compatible with the frame material can be used to

10 fuse the two parts together at the junction. Each of the two parts frame assembly

134 and 136 can therefore be produced in series at low cost using a two part mould

after which openings such as openings 88 are simply drilled.

The description of the supporting frame being complete, the following description will

disclose how the primary and secondary sub-coils are wound around a supporting

frame, and how two coiled supporting frames are assembled to provide a

transformer coil, and how an in-line annealed amorphous metal ribbon is then rolled

up on a mandrel around the coils to form a core. The coil arrangements of the

present invention and the rolling of the ribbon can be assembled in a fully automated

20 manner.

Figure 23 shows a schematic representation of a means used to assemble coil

arrangements. An empty supporting frame 9 is mounted on a mandrel driven by a

servo motor drive. Around the rotating frame, are located different material feeders,

comprising: a reel containing a conductor wire 191; a plurality of reels each

containing insulating strips 192 having different widths to fit in each row within the

supporting frame; a cassette containing duct spacers 193; a reel containing a

conductor strip 194; and a reel containing an insulating strip 195 slightly larger than

the conductor strip. Each material feeder is provided with a robot manipulating arm

30 and a cutting actuator to bring, engage, wound and cut the material on the rotating
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supporting frame 9. Preferably, each reel 191, 194 and 195 contains enough

material to wind an integer number of supporting frames 9 to avoid making splices

and to keep scrap to a minimum. The insulating strips 192 are partially pre-cut to

make them frangible at a required length, and only require a small sudden tensile

force to liberate the strip from the roll.

In the assembled supporting frames shown in Figure 18. there are left-coil and rightGail supporting frames 199 and 200. Referring again to Figure 23, to coil the primary

sub-coil on a left-coil or a right-coil supporting frame, the conductor wire is first

10 brought by the robot manipulating arm and guided through the exit opening 197

aligned with the first bottom rowan one side of the supporting frame. The conductor

is then wound for a predetermined number of turns On a single layer to fill the first

row. Before engaging the wire on the next row, a segment of insulating strip 192

having the corresponding row width is wound around the frame to completely cover

the first row with both extremities overlapping each other before starting to coil the

next row with the conductor wire. If ducts are planned in between two determined

rows, spacers 193 are picked from the cassette and are installed on the designated

limb of the supporting frame. These spacers could be pre-glued to an insulating strip

to ease installation. When the last row is coiled, the wire is cut and guided out

20 through the exit opening 198 which is aligned with the row and which exits on the

same side with the exit opening 197 on the supporting frame. Figure 24 shows a

case where the primary sub-coil is provided with a plurality of exit leads on the last

coiled row for eventual connections to a tap selector. While the last row is being

coiled, a protuberant conductor loop 141 is formed at a predetermined turn count.

Each loop 141 is twisted to form a lead 142 which is then dressed with an insulating

sleeve and bent on the side of the coil supporting frame, preferably in the slots 108

shown in Figure 14. The primary sub-coil is then completed and has exit leads on

the side of the supporting frame associated to a left-coil or a right-coil arrangement,

whichever is being wound. The next step will be the winding of the secondary sub30 coil.
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The winding of the secondary sub-coil consists of winding both an insulating and

conductor strip over the primary sub-coil of overall rectangular shape. When winding

the conductor strip, transverse exiting leads must be provided at the extremities of

the conductor strip to provide an electrical connection to the coil. Strip segments of

conductors could be welded perpendicularly at each end of the strip to form a right

angle exit. In the present invention, the robot manipulating arm includes means to

fold and shape the extremity of the strip 194. Figure 25, sequences A to E show with

schematic views the steps involved to fold and wind the conductor strip 194 side by

10 side with an insulating strip 195 to form one secondary sub-coil in piggyback over

the primary sub-coil. The left portion of the drawing in each sequence shows a top

view of the supporting frame being wound with the conductor foil and the insulating

strip arriving over the supporting frame which is rotating clockwise with reference to

the right drawing showing the supporting frame from a front view. The dashed lines

on the right "front view" drawing are indicative of elements hidden behind the

supporting frame. The drawing sequences show the winding of a left-coil

arrangement. For a right-coil arrangement, differences in the folding procedure will

be shown with a dashed line and the identifier will include an additional superscript

mark ( I ). Starting with sequence A, prior to starting the winding of the conductor

20 strip 194, a thick insulating layer 19 is built by winding multiple turns with the

insulating strip 195. Once the desired dielectric thickness is obtained, the lead of the

conductor strip 194 is folded once by the robot manipulating arm on the opposite

side to the primary sub-coil leads 197 and 198 location, along folding line 201 to

create a lead 202 extending transversely to the coil. Then, the length of a lead must

be sufficiently long to allow connection to a transformer tank bushing with further

upward folding, or to the exit lead of another coil. The folding line shown can have an

angle between 15 and 75 degrees which will provide a lead at an exit angle from 30

to 150 degrees with reference to the side of the supporting frame. Such play in the

angle can be practical for aligning the upward folded lead strip with the bushing

30 attached to a curved wall of a round or oval transformer tank. For the purposes of
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PCT/CA2010/001845

the description, the strip is folded along a 45 degrees folding line. In sequence B, the

folding line 201 of the strip 194 is brought on top of the supporting frame limb where

the exits leads 197 and 198 are located. Both conductor strip 194 and insulating strip

195 are then wound simultaneously for an appropriate number of turns. In sequence

C, the conductor foil 194 is cut and the trailing end is folded twice along two 45

degree folding lines 203 and, 204 (204') on the opposite side to the primary sub-coil

leads 197 and 198 location to provide a lead 205 (205') extending in parallel with the

coil and oriented in the same direction (opposite direction for a right-coil) as the

direction of travel of the strip being wound. The location of the folding line 203 on the

10 strip 194 has been chosen in order to arrive on top of the limb of the supporting

frame where the exit leads 197 and 198 are located as shown in sequence D. The

winding of the secondary sub-coil is then completed. To finalize the winding of the

coil arrangement, a few turns of the insulating strip 195 are wound. Sequences E

and E' show completed left-coil and right-coil arrangements.

Figure 26, sequences A to J show with schematic views the steps involved to fold

and wind the conductor strip 194 with insulating strip 195 to form two secondary subcoils in piggyback over the primary sub-coil. The drawing sequences show the

winding of a left-coil arrangement. For a right-coil arrangement, differences in the

20 folding procedure will also be shown with a dashed line and the identifier will include

an additional superscript mark ( , ). Prior to starting the winding of the conductor strip

194, a thick insulating layer 19 is built by winding multiple turns with the insulating

strip 195. Once the desired dielectric thickness is obtained, the lead of the conductor

strip 194 is folded once by the robot manipulating arm on the opposite side to the

primary sub-coil leads 197 and 198 location, along a 45 degree folding line 150 to

create a lead 152 extending perpendicularly to the coil. In sequence B, the folding

line 150 of the strip 194 is brought on top of the supporting frame limb where the

exits leads 197 and 198 are located. Both conductor strip 194 and insulating strip

195 are then wound simultaneously for an appropriate number of turns. In sequence

30 C, the conductor foil 194 is cut and the trailing end is folded twice along two 45
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PCT/CA2010/001845

degree folding lines 154 (154') and, 155 (155') on the same side (opposite side for a

right coil) to the primary sub-coil leads 197 and 198 location to provide a lead 156

(156') extending in parallel with the coil and oriented in the opposite direction (same

direction for a right-coil) with respect to the direction of travel of the strip. The

location of the folding line 154 (154') on the strip 194 has been chosen in order to

arrive on top of the limb of the supporting frame which is the opposite to the one

where the exit leads 197 and 198 are located as shown in sequence D. Then, a few

turns of insulating strip 195 are wound to completely cover the first secondary subcoil and the winding of the first secondary sub-coil is now completed as shown in

10 sequence E. Next, in sequence F, with the conductor strip now being fed from the

other side and the supporting frame now rotating counter clockwise, the end of the

conductor strip 194 is folded twice on the opposite side (same side for a right-coil)

with respect to the primary sub-coil leads 197 and 198, along two 45 degree folding

lines 157 (157') and 158 (158'), to provide a lead 159 (159') extending in parallel and

oriented in same direction (opposite direction for a right-coil) with respect to the

direction of travel of the strip; The first folding in sequence C could have been done

on the opposite side (same side for a right-coil) with respect to the primary sub-coil

leads 197 and 198, in which case the first folding in sequence F will be done on the

same side (opposite side for a right-coil) with respect to the primary sub-coil leads

20 197 and 198. In sequence G, the folding line 157 (157') of the strip 194 is brought

on the supporting frame limb opposite to the limb where the exits leads 197 and 198

are located. Both conductor strip 194 and inSUlating strip 195 are then wound

simultaneously for an appropriate number of turns. In sequence H, the conductor foil

194 is cut and the trailing end is folded twice on the opposite side to the primary subcoil leads 197 and 198 along two 45 degree folding lines 160 and 161 (161') to

prOVide a lead 162 (162') extending in parallel and oriented in opposite direction

(same direction for a right-coil) with respect to the direction of travel of the strip. The

location of the folding line 160 on the strip 194 has been chosen in order to arrive on

top of the limb of the supporting frame where the exit leads 197 and 198 are located

30 as shown in sequence I. The winding of the second secondary sub-coil is then
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PCT/CA2010/001845

completed. To finalize the winding of the coil arrangement, a few extra turns of the

insulating strip 195 are wound. Sequences J and J' show completed left-coil and

right-coil arrangements.

Figures 27, sequences A to F show steps on how to assemble a core-coil

arrangement to produce a transformer kernel. First, in sequence A, the two coil

arrangements, one left-coil and one right-coil, are put back-to-back with the leads

156 with 156', 159 with 159', and 162 with 162' aligned towards each other with their

ends overlapping. The two coil arrangements are then secured together using

10 attaching means shown in Figure 18. The sequences shown involve usage of coil

arrangements comprising two secondary sub-coils. In the case of a single secondary

sUb-coil, the leads 156, 156', 159 and 159' are not present. Then in sequence 8, a

ductile and cuttable in-line curved annealed iron-based amorphous metallic ribbon is

rolled on a mandrel pre-installed around the central circular limb formed by the backto-back coil arrangements to form a circular core 1. In sequence C, when the core is

completed, the two coil arrangements are unsecured and pushed away to lean

against the internal wall of the window opening in the circular core 1 as shown in

Figure 4 and, are secured again together. Spacers 37 are then inserted between the

two coil arrangements and the leads 162 with 162' and 198 with 198' are welded

20 together at welding point 163 and 166. In sequence 0, the leads 156 with 156' and

159 with 159' located under the circular core (upside-down view) are also welded

together at welding points 164 and 165. The circular core transformer assembly of

the present invention is best suited to be installed in an oval tank. In sequence E, the

core-coil arrangement is put into a transformer oval tank comprising three low

voltage bushings 212, 213 and 214 which are then respectively aligned and

connected to upward folded leads 152, 162-162.' and 152'. A top cover bushing 215

(high voltage) and ground lead 216 are respectively connected to reads 197 and

197'. Some tanks could be equipped with four low voltage bushings instead, where

the leads 162 and 162" would not be welded together but would rather be each

30 connected to a respective bushing. In cases where the core-coil arrangement would
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PCT/CA2010/001845

only comprise one secondary coil, the bushing 213 would not be present. Figure 28

shows a front view of the core-coil arrangement in the tank with the bushings up

front. Each lead 152, 162-162' and 152" is linked to the bushing by an upward folded

strip segment that may have been welded on the lead, or which is realized by further

folding the leads that were extending further away from the coils when they were

wound in Figures 25 A to E' or 26 A to J'.

In cases where the conductor foil 194 produces bulky leads that are too large when

folded, the winding sequences Figures 25 A to E' or 26 A to J' may incorporate an

10 additional folding step as shown in Figure 29A. The width of a lead is reduced by half

by performing an additional fold along the folding line 165 once the first 45 degrees

fold is executed and before further folding is performed. This will provide a coil

arrangement with narrower leads as shown in the Figure 29B.

The distribution transformer of the present invention also provides a method to

assemble the core with a back-to-back coil arrangement. Figures 30A to 30C show a

mandrel assembly for rolling up a ribbon. It comprises two walls 230 and 231 each

having an arc shape of a predetermined internal radius and a thickness, and having

a height both at least equal to the width of an annealed iron-based amorphous

20 metallic ribbon. Preferably, the wall 230 is provided on each of its two ends with an

internal S-shaped pattern cavity 232 which is each intended to fit in an outer Sshape pattern cavity 233 located on both ends of the wall 231. When the two walls

are aligned and pressed against each other, they will snap together as shown in

Figure 30B and they will form a cylindrical tube having the given internal radius and

given height. The walls of the mandrel are preferably made of a pressed or moulded

rigid inSUlating material, although stainless steel or any non-ferromagnetic material

having good structural rigidity cOuld also be used. Both ends of the walls have a half

disc flange 170 such that when the two walls are snapped, a mandrel with flanges is

formed. A binder can also be used to fuse the two walls and flangestogether.

30
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PCT/CA2010/001845

Referring to Figure 31, completed left-coil and right-coil arrangements 199 and 200

are put back-to-back and secured together with thethreaded, rods 115, nuts 119 and

washers 117. The nuts 119 are positioned on the threaded rods 115 such that when

the coil arrangements are pushed towards each other, the two arc shaped back to

back limbs fit within a circular outline as shown in Figure 3 and the coil arrangements

are aligned. Then the nuts 119 are tightened to squeeze the protuberant portions 84

between the nuts 119, thus creating a complete rigid assembly having constant

geometric dimensions from one assembly to the next. To assemble the core, in

Figure 32, the two walls 230 and 231 are mounted around the central circular limb of

10 the back-to-back coil arrangement and are pressed together until they snap in place

as shown in Figure 33. When snapped in place, the cylindrical mandrel has an

internal radius slightly greater than the outer radius of the circular outline of the two

back to back arc shaped limbs and its height is slightly smaller than the height of coil

supporting frames window opening in order to allow the mandrel to rotate freely

around the limb. To roll up an annealed amorphous ribbon material onto the formed

mandrel, the back-to-back coil arrangement is installed and held in place using the

bollards 90 in a predetermined position by a retaining setup. Then, as shown in

figure 34, at least three rollers 234 with at least one provided with small flanges 236

are brought by actuators to be positioned around the periphery of the mandrel

20 flanges 237 with all rotating axes in parallel with the circular limb center axis (Xo,Yo).

Three narrow rollers 234 can be used on each flange 237 of both sides of the

mandrel to clear the access of the middle portion of the mandrel for the ribbon. The

angular distance between rollers can be different as long as they are localized over

an angle greater than 180 degrees to keep the mandrel from getting out of the axis

of rotation. The internal distance between the flanges 236 of the rollers 234 from one

side of the mandrel to the other is just wide enough to allow the width of the mandrel

to fit in between to maintain its axial position in order to avoid frictional contact with

one of the limbs surface of the supporting frames. The XY position for each of the

three rollers 234 is precisely controlled by the actuators based on commands

30 provided by a CPU. In order to rotate the mandrel and the accumulating ribbon, at
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PCT/CA2010/001845

least one of the rollers 234 is motorized. Since the back-to-back coil arrangement is

installed and held in place in a predetermined position, the CPU knows the position

of the circular limb center axis' (Xo,Yo). If greater precision is needed, each roller can

successively push on the mandrel until it leans against the circular limb and then the

CPU records the corresponding XY position, as shown in Figure 35. With the

recorded data and the radius of each roller 324, the CPU computes the center

position (Xo,Yo) of the circular limb. Once the core is completed, the nuts 119 are

loosened and positioned on the threaded rods 11.5 such that when the two coil

arrangements are pushed away, they will lean against the internal face of the core

10 mandrel as shown in Figure 4 and will be aligned. It is preferable to place the

transformer kernel in upright position to allow the core to lean on the provided flat

surface of the two horizontal bottom limbs of the coil frames, therefore providing

support to the core. Then, the nuts 119 are tightened to squeeze the protuberant

portions 84 between the nuts, thus creating a complete rigid transformer core-coil

assembly. The spacers 37 are then inserted between the two coil arrangements and

the leads are welded together.

Preferably, the ribbon rolling process of Figure 34 includes an automated ribbon

feeding reel switcher to provide uninterrupted ribbon supply and a ribbon tensioner

20 to control the tension in the ribbon during rolling up. Continuous supply of ribbon can

be provided by bringing a filled reel in rotation in proximity of the emptying reel, and

by launching and fiXing the ribbon end of the filled reel to the trailing end of the

ribbon leaVing the emptying reel. Preferably, continuous rolling-up of a ribbon to form

cores of transformer kernels can be provided by bringing the mandrel of a new coil

arrangement in rotation in proximity of the filling mandrel of the core-coil

arrangement being formed, and by cutting the ribbon and fixing the incoming ribbon

end to the mandrel while the completed transformerkernel is moved away.

Figures 36 to 38 show a final transformer kernel assembled according to the present

30 invention. Insulating sleeves 240 have been added around the primary coil external
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PCT/CA2010/001845

leads. Insulating sleeves could also be provided on the secondary leads if required.

However, the preformed shapes done by a robot manipulating arm when the coils

were formed help avoid usage of insulating sleeves on the secondary leads as they

are preformed to fit in the transformer tank and to be aligned with the tank low

voltage bushings for easy connection. This will reduce labour and costs for tanking

the kernel.

Figure 39 shows the core-coil arrangement further comprising bracing members 243

and 244 that are held against the external limbs of the coil arrangement by straps

10 250 once the core is formed (core is not shown for purpose of clarity). The bracing

member 243 is preferably made of an insulating material and comprises slots 245

that will provide vertical ducts along the secondary coil surface for cooling fluid to

flow up via a chimney effect. Additional vertical slots 246 are formed in the bracing

member with opposite upper and lower obstructions 247 to replace the side ducts

109 and 111 of Figure 17. These ducts increase cooling efficiency by providing

increased flow of fluid near the surface of the coil. The bracing member 244 also

includes slots 248 and an opening 249 to allow a flow of cooling fluid near the top

and bottom surface of the secondary coils. The bracing members will increase the

transformer ability to withstand repulsion forces between the primary and secondary

20 coils under short-circuit conditions. The frame 243 will work with supporting frames

244 and 245 to keep the primary and secondary sub-coils from separating apart due

to the repulsive forces created by the short-circuit currents flowing in respective subcoils.

More than two core-coil arrangements produced with the system of the present

invention can be grouped back to back together to produce a three-phase

transformer as shown in Figure 40.

The manufacturing of transformer kernels in the present invention can be fully

30 automated and is compatible for mass production of transformer kernels using
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compact assembling equipments occupying small floor space. Mass production of

transformer kernels at a given standard efficiency becomes possible through subcomponent manufacturers which will provide the kernels to transformer assemblers.

Such centralization of transformer kernel manufacturing brings economies of scale

by eliminating significant core and coil assembling equipments, labour and floor

space required at each transformer assembler plant which contributes to increase

the cost of the transformer. Referring to Figure 41, core-coil arrangements produced

with the system of the present invention can be grouped in rows on a on a rack 252

and multiple racks 252 containing a number of coil arrangements 251 can be put in a

10 sealed container 253 for shipment to transformer assemblers which will assemble

each core-coil arrangement with the tank, oil and other required accessories. The

rack comprises a base means 254 with foot-prints for supporting a group of core-coil

arrangements and a top means 255 for securing the group of core-coil arrangements

with the base. Each rack of core-coil arrangements can be stacked to fill the

container height. Also, each rack of core-coil arrangements can be wrapped with a

plastic film in order to be protected from dust. An efficient shipping enclosure is

therefore provided for shipping the transformer kernels in quantity from the

transformer kernel manufacturer to transformer assemblers.

20 Referring to Figure 42, a distribution transformer final assembly comprising an oval

tank which is capable of enclosing the transformer kernel of the present invention is

shown. Such a distribution transformer will have a centre of gravity located closer to

the pole attaching bracket, thus putting less stress on the holding bracket.

Although preferred embodiments of the present invention have been described in

detailed herein and illustrated in the accompanying drawings, it is to be understood

that the invention is not limited to these precise embodiments and that various

changes and modifications may be effected therein without departing from the scope

or spirit of the present invention.
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WHAT IS CLAIMED:

50

PCT/CA2010/001845

1. A support frame for an electrical transformer assembly, comprising:

-two loop-shaped parts, each loop-shaped part having a plurality of limbs,

each limb having a peripheral recessed portion in which a primary electrical coil is

mountable, and at least one secondary coil is mountable in piggyback on said

primary electrical coil, one limb of each loop-shaped part having a straight section;

and

-an adjustable attaching means for attaching one of the loop-shaped parts

10 with respect to the other loop-shaped part and adjusting a distance therebetween, so

that only the straight sections are adjacent and form a central leg, the central leg

being for receiving a magnetic core distinct from the attaching means.

2. The support frame according to claim 1, wherein the loop-shaped parts are

made of a material selected from the group comprising fibreglass, epoxy, paper,

cardboard, wood and wood composites.

3. The support frame according to claim 1 or 2, further comprising securing

means for securing the loop-shaped parts to a transformer tank.

20

4. The support frame according to claim 3, wherein the securing means

comprises:

-a base frame;

-first fixing means for fixing a bottom portion of the loop-shaped parts to the

base frame; and

-second fixing means for fixing the base frame to the transformer tank.

5. The support frame according to claim 3, wherein the securing means

comprises:

-a base frame;
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-first fixing means for fixing a top portion of the loop-shaped parts to the base

frame; and

-second fixing means for fixing the baseframe to the transformer tank.

6. The support frame according to claim 3, wherein the securing means

comprises alignment means for aligning the loop-shaped parts with respect to the

base frame.

7. The support frame according to claim 3, further comprising handling means

10 located on a top portion of the loop-shaped parts for handling and displacing the

support frame from one location to another.

8. The support frame according to claim 7, wherein the securing means

comprises:

-a base frame;

-first fixing means for fixing the handling means of the loop-shaped parts to

the base frame; and

-second fixing means for fixing the base frame to the transformer tank.

20 9. The support frame according to anyone of claims 1 to 8, wherein a selected

one of said plurality of limbs other than those forming the central leg further provides

channels for conducting fluids adjacently and transversely to the coils, each of the

channels having one inlet on one side of said one limb and one outlet on the other

side of said one limb.

10. The support frame according to claim 9, wherein the channels form an angle

with respect to the horizontal to produce a chimney effect in the fluids.

11. The support frame according to claim 9, further comprising a first chimney for

30 enclosing the inputs of the channels, the first chimney having a closed top and an
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PCT/CA2010/001845

open bottom, and a second chimney for enclosing the outputs of the channels, the

second chimney having a closed bottom and an open top, to produce, by means of

the first chimney and the second chimney, a chimney effect in the fluids.

12. The support frame according to anyone of claims 9 to 11, wherein the

channels are formed by transversal grooves in the recessed portion of the loopshaped parts.

13. The support frame according to anyone of claims 9 to 11, wherein the

10 channels are delimited by insulating spacers positioned between adjacent rows of

coils once mounted on the loop-shaped parts.

14. The support frame according to anyone of claims 1 to 13, wherein said one of

the loop-shaped parts is positionable with respect to the other loop-shaped part by

the adjustable attaching means such that the loop-shaped parts are selectively

separated by a fIrst spacing distance and a second spacing distance, said second

spacing distance being greater than the first spacing distance, the support frame

further comprising a mandrel surrounding the central leg, said mandrel being sized

to rotate freely around the central leg with the loop-shaped parts separated by said

20 first spacing distance and said mandrel being inhibited from rotating around the

central leg with the loop-shaped parts separated by said second spacing distance.

15. The support frame according to claim 14, wherein the mandrel is made from

an insulating material selected from the group comprising fibreglass, epoxy, paper,

cardboard, wood and wood composites.

16. The support frame according to claim 14 or 15, wherein the mandrel

comprises interlockable first and second half portions.
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17. The support frame according to anyone of claims 14 to 16, wherein the

mandrel further comprises opposite flanges at extremities thereof.

18. The support frame according to anyone of claims 1 to 8, further comprising at

least one bracing member mountable on an external surface of at least one of said

limbs other than those forming the central leg for securing the coils, once mounted,

in position within the loop-shaped parts.

-,.

19. The support frame according to claim 18, wherein said at least one bracing

10 member provides channels for conducting fluids adjacently to the coils, each of the

channels provided by said at least one bracing member having an inlet and an outlet

for allowing circulation by a chimney effect.

20. A loop-shaped part of a support frame of an electrical transformer assembly,

comprising:

-a plurality of limbs on which a primary electrical coil and at least one

secondary electrical coil are mountable, each limb having a peripheral recessed

portion in which the primary electrical coil is mountable, and said at least one

secondary coil being mountable in piggyback on said primary electrical coil, one limb

20 of the loop-shaped part having a straight section, the peripheral recessed portion

comprising:

-a base portion for supporting said primary electrIcal coil;

-slanting sidewall portions extending from both sides of said base

portion, said slanting portions comprising a plurality of steps allowing a

stacking of rows of conductors and insulating layers of the primary

electrical coil.

21. The loop-shaped part according to claim 20, wherein a height of a step in a

corner between adjacent perpendicular limbs is gradually reduced.

30
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22. The loop-shaped part according to claim 20, wherein one of said plurality of

limbs further provides channels for conducting fluids adjacently and transversely to

the coils. each of the channels having one inlet on one side of the loop-shaped part

and one outlet on the other side of the loop-shaped part and wherein a height of a

step along a limb is increased by a length to accommodate said inlet and outlet.

23. The loop-shaped part according to claim 20, wherein one of said plurality of

limbs further provides an tap input opening on one side of the loop-shaped part,

allowing connection of a tap to the coils, once mounted, and wherein a height of a

10 step along a limb is increased by a length to accommodate said tap input opening.

24. The loop-shaped part according to claim 20, wherein predetermined steps are

formed for bridging a last coil loop of a row with a first coil loop on an adjacent row.

25. The loop-shaped part according to claim 24, wherein said bridging is

performed at corners of perpendicular limbs.

26. The loop-shaped part according to anyone of claims 20 to 25. wherein the

loop shaped part comprises interlockable first and second half portions.

20

27. The loop-shaped part according to claim 20, wherein one of said plurality of

limbs further provides channels for conducting fluids adjacently and transversely to

the coils, each of the channels having one inlet on one side of the loop-shaped part

and one outlet on the other side of the loop-shaped part, and wherein the channels

are formed by transversal grooves traversing the base portion and at least one of the

slanting sidewall portions.

28. The loop-shaped part according to claim 27, wherein a port fluidly connects

the inlets to the transversal grooves traversing the base portion.

30
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29. The loop-shaped part according to anyone of claims 20 to 28, wherein an

inner surface of the loop-shaped part at the limb having the straight section is

substantially semi-cylindrical and an inner surface of the loop-shaped part at the

limbs perpendicular to said limb having the straight section is flat.

30. The loop-shaped part according to claim 29, wherein a radius of curvature of

the inner surface that is substantially semi-cylindrical is smaller than an inner radius

of a cylindrical core mountable around said loop-shaped part.

10 31. An electrical coil assembly comprising an electrical coil and a frame onto

which the coil is wound, made of an electrical conductor strip having a first end and a

second end, at least one of the ends being folded over itself along a first fold line

according to an angle between 15 and 75 degrees such that said one end extends

transversally with respect to a plane where the coil lies to provide a connection lead.

32. The electrical coil assembly according to claim 31, wherein the angle is 45

degrees.

33. The electrical coil assembly according to claim 31 or 32, wherein said one end

20 folded over itself is further folded along a second fold line parallel to a longitudinal

axis of the strip.

34. The electrical coil assembly of claim 31, in combination with an electrical

transformer core assembly which comprises a support frame comprising a loopshaped part, said loop-shaped part comprising a plurality of limbs and first and

second opposite sidewalls, two of said plurality of limbs forming opposite top and

bottom straight sections, said coil assembly comprising:

-a primary electrical coil wound around said loop-shaped part, said primary

electrical coil comprising first and second primary terminals at opposite ends
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of said primary coil, said first and second primary terminals extending from the

first sidewall of the loop-shaped part;

-a secondary electrical coil wound around the primary electrical coil, said

secondary electrical coil being made from a conductor strip and comprising

first and second secondary terminals at opposite first and second ends of said

secondary coil, the first secondary coil terminal being formed by folding the

first end of the strip over itself along a first 45 degree fold line with respect to

the first sidewall such that a first length of the strip extends perpendicularly

with respect to and from the second sidewall opposite the first sidewall from

10 which the first and second primary sub-coil terminals extend,

the second secondary terminal being formed by folding the second end of the

strip over itself along a second 45 degree fold line to form a first intermediate

fold and folding the second end of the strip over the first intermediate fold

along a third 45 degree fold line perpendicular to the second 45 degree fold

line such that a second length of the strip extends in parallel with and outside

said first and second sidewalls.

35. A method of assembling an electrical transformer kernel assembly, comprising

the steps of:

20 a) winding a primary electrical coil around a first loop-shaped part having a

peripheral recessed portion along its outer surface for receiving the primary electrical

coil, the first loop-shaped part having at least one straight section;

b) winding a secondary electrical coil on piggyback on the primary electric coil

around the first loop-shaped part;

c) winding a primary electrical coil around a second loop-shaped part having a

peripheral recessed portion along its outer surface for receiving the primary electrical

coil, the second loop-shaped part having at least one straight section;

d) winding a secondary electrical coil on piggyback on the primary electric coil

around the second loop-shaped part;
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PCT/CA2010/001845

e) attaching the first loop-shaped part with respect to the second loop-shaped

part so that only the straight sections are adjacent and form a central leg;

f) adjusting a distance between the first loop-shaped part and the second

looped shaped part to a first spacing distance;

g) installing a mandrel around said central leg, said mandrel being sized to rotate

freely around the central leg when the first loop-shaped part and the second looped

shaped part are spaced by said first spacing distance; and

h) winding a metallic ribbon around the central leg to form a magnetic core,

wherein the winding step h) is distinct from the attaching step e).

10

36. The method according to claim 35, further comprising the steps of:

i) adjusting the distance between the first loop-shaped part and the second

looped shaped part to a second spacing distance greater than the first spacing

distance, such that the mandrel is inhibited from rotating around the central leg; and

j) inserting spacer elements between the adjacent straight sections forming the

central leg.

37. The method according to claim 35 or 36, further comprising, during steps a)

and c), the steps of:

20 aa) forming a plurality of conductor loops with the primary electrical coil at distinct

predetermined turn counts;

bb) individually twisting each of the conductor loops to form connection leads;

cc) inserting insulating sleeves between adjacent twisted conductor loops; and

dd) bending said leads transversally with respect to the winding of the primary

electrical coil.

38. A system for assembling an electrical transformer kernel assembly, comprising:

-a first winding system for winding a primary electrical coil around a first loopshaped part and second loop-shaped part respectively, each loop-shaped part

30 having a peripheral recessed portion along its outer surface for receiving the
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PCT/CA2010/001845

primary electrical coil, the first loop-shaped part and the second loop-shaped

part each having at least one straight section;

-a second winding system for winding a secondary electrical coil on piggyback

on the primary electric coil around the first loop-shaped part and the second

loop-shaped part respectively;

-an attaching system for attaching the first loop-shaped part with respect to

the second loop-shaped part by means of an adjustable attaching means, so

that only the straight sections are adjacent and form a central leg;

. -a mandrel installation system for installing a mandrel around said central leg,

10 said mandrel being sized to rotate freely around the central leg when the first

loop-shaped part and the second looped shaped part are spaced by a first

spacing distance; and

-a third winding system for winding a metallic ribbon around the central leg to

forma magnetic core, the core being distinct from the adjustable attaching

means.

39. The use of the method as claimed in claims 35 to 37 to manufacture electrical

transformer kernel assemblies in series production.

20 40. A storage container for containing a plurality of electrical transformer kernel

assemblies assembled by the method of claims 35 to 37.
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INTERNATIONAL SEARCH REPORT International application No.

PCT/CA20101001845

A CLASSIFICATION OF SUBJECT MATTER

IPC: H01F 41/08 (2006.01), H01F 27/02 (2006.01), H01F 27/06 (2006.01), H01F 30/16 (2006.01)

According to International Patent Classification (IPC) or to both national classification and IPC

B. FIELDS SEARCHED

Minimum documentation searched (classification system followed by classification symbols)

IPC: HOIF 41/08 (2006.01), HOIF 27/02 (2006.01) HOIF 27/06 (2006.01) HOIF 30/16 (2006.01)

Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched

Electronic database(s) consulted during the international search (name of database(s) and, where practicable, search terms used)

Epoque Epodoc, US Full Txt database: IEEE, Canadian Patent Database (Keywords transformer assembly, loop, limbs, legs, recessed,

fibreglass, epoxy, paper, cardboard, wood, composites, support frame, base fi:ame, distribution transformer)

C DOCUMENTS CONSIDERED TO BE RELEVANT

CategOlY* Citation of document, with indication, where appropriate, ofthe relevant passages

A EP318322 (Book) 31 May 1989 (31-05-1989)

(see whole document)

A .TP 2009188034 (Futai et aL) 20 August 2009 (20-08-2009)

(see whole document)

A GB126,271 (Holslag) 15 March 1920 (15-03-1920)

(see whole document)

A US 4,781,348 (Cutforth et aL) 1 November 1988 (01-11-1988)

(see whole document)

A US 3,686,561 (Spreadbmy) 22 August 1972 (22-08-1972)

(see whole document)

A EP 518,565 (Allan et aL) 16 December 1992 (16-12-1992)

(see whole document)

Relevant to claim No.

1-40

1-40

1-40

1-40

1-40

1-40

[ ] Further documents are listed in the continuation ofBox C.

Special categories of cited docmnents

")"." dOCUlllt:;l1t de±1ning the general state of the 3rt which is not considered to be of partIcular rele,\Tance

"E" earlier application or patent but published on or at1er the international filmg date

"L"' document "\I'hich may thrm:v doubts on priority claim(s) or ,'.'hich is CIted to establIsh the publIcatIon date of another CItatIon or other specwl reason (as specdied)

document referring to an oral disclosure, use, exhibition or other means

"P" document published prior to the international filing date but later than

the pnont:v date claImed

Date of the actual completion of the international search

8 February 2011 (08-02-2011)

Name and mailing address of the ISAICA

Canadiall hltellectual Property Otlice

Place du Portage I, C114 - 1st Floor, Box PCT

50 Victoria Street

Gatineau, Quebec KIA OC9

Facsimile No. 001-819-953-2476

Form PCTIISAl210 (second sheet) (July 2009)

[X] See patent tinnily almex.

"T" later docmnent publisheda±1er the international filing date or priority

date and not 111 con11Ict "\'lith the apl)hcatIon but citeato understand - the pnnciple or theory lUlderlY111g t le 111\ientIon

C"X" document of particular relevance', the claimed invention cmmot be conSIdered novel or cannot be consldered to 111volve an 111ventIve

step ';vhen the doclUllent is taken alone

c.ycc docmnent of partIcular relevance. the clallned 111ventlOn emmot be conSIdered to Il1\/Olve 3n 111\ientI,,-'e step yvhen the document lS

comb111ed YVlth one or more other such documents, such combination being obvious to a person skilled in the 3rt

"&" document member of the same p3tent family

Date ofmailing of the international search report

10 FeblUaIy 2011 (10-02-2011)

Authorized otlicer

Camran Syed (819) 934-4550

Page 201'3
INTERNATIONAL SEARCH REPORT

Information on patent family members

International application No.

PCT/CA20 10/00 1845

Patent Document

Cited in Search Report

EP0318322Al

Publication

Date

31 May 1989 (31-05-1989)

Patent Family

Member(s)

AU2497688A

AU611965B2

JPH0189714U

N0885272DO

N0885272A

US4901182A

Publication

Date

01 June 1989 (01-06-1989)

27 June 1991 (27-06-1991)

13 June 1989 (13-06-1989)

25 November 1988 (25-11-1988)

29 May 1989 (29-05-1989)

13 FebruaIy 1990 (13-02-1990)

JP2009188034A

GB126271A

US4781348A

US3686561A

EP0518565Al

1995)

20 August 2009 (20-08-2009) None

15 March 1920 (15-03-1920) FR494597A

01 November 1988 (01-11-1988) None

22 August 1972 (22-08-1972) BE782437Al

BR7202223DO

CA962346Al

FR2134409Al

FR2134409Bl

GB1385224A

IT953694B

JP52047535B

JP53044650B

NL7205473A

ZA7201496A

16 December 1992 (16-12-1992) DE69205892Dl

DE69205892T2

DE69222066D1

DE69222066T2

DE69223162D1

DE69223162T2

EP0518565Bl

EP0643405A2

EP0643405A3

EP0643405Bl

EP0643406A2

EP0643406A3

EP0643406Bl

GB9211904DO

GB2257840A

GB2257840B

GB9422804DO

GB2283864A

GB2283864B

GB9112435DO

JP6181135A

US5387894A

US5455553A

23 October 1972 (23-10-1972)

09 August 1973 (09-08-1973)

04 FebruaIy 1975 (04-02-1975)

08 December 1972 (08-12-1972)

06 August 1976 (06-08-1976)

26 FebruaIY 1975 (26-02-1975)

10 August 1973 (10-08-1973)

03 December 1977 (03-12-1977)

30 November 1978 (30-11-1978)

25 October 1972 (25-10-1972)

29 November 1972 (29-11-1972)

14 December 1995 (14-12-

04 Apri11996 (04-04-1996)

09 October 1997 (09-10-1997)

02 JanuaIy 1998 (02-01-1998)

18 December 1997 (18-12-1997)

12 March 1998 (12-03-1998)

08 November 1995 (08-11-1995)

15 March 1995 (15-03-1995)

28 June 1995 (28-06-1995)

12 November 1997 (12-11-1997)

15 March 1995 (15-03-1995)

28 June 1995 (28-06-1995)

03 September 1997 (03-09-1997)

15 July 1992 (15-07-1992)

20 JanuaIy 1993 (20-01-1993)

10 JanuaIy 1996 (10-01-1996)

04 JanuaIy 1995 (04-01-1995)

17 May 1995 (17-05-1995)

10 JanuaIy 1996 (10-01-1996)

31 July 1991 (31-07-1991)

28 June 1994 (28-06-1994)

07 FebruaIy 1995 (07-02-1995)

03 October 1995 (03-10-1995)

Form PCTIISAl210 (patent famIly mmex) (July 2009) Page 3 01'3