(12) INTERNATIONALAPPLICATIONPUBLISHED UNDERTHEPATENTCOOPERATIONTREATY(PCT) (19)WorldIntellectualProperty Organization InternationalBureau (43)InternationalPublicationDate 26May2011 (26.05.2011)



# - - (51) InternationalPatentClassification: H01F41/08(2006.01) H01F27/06(2006.01) H01F27/02 (2006.01) H01F30/16(2006.01) (21) InternationalApplicationNumber: PCT/CA2010/001845 (22) InternationalFilingDate: 18November2010 (18.11.2010) (25) FilingLanguage: English (26) PublicationLanguage: English (30) PriorityData: 61/262,603 19November2009 (19.11.2009) US (71) Applicant (for all designated States except US): HYDRO-QUEBEC [CA/CA]; 75, boul.**Rell(~-Levesque** Ouest, 22eEtage, 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) H2Z2B7 (CA). (81) Designated States (unless otherwise indicated,for every kindof national 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 kindof regionalprotection 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). DeclarationsunderRule4.17: as to applicant's entitlementto applyfor andbe granted apatent(Rule 4.17(ii))



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# - [Continuedon nextpage) (54) Title: ELECTRICALTRANSFORMERASSEMBLY (57) Abstract: A support frame for an electrical transformer assembly, comprisingtwo loop-shapedparts, eachloop-shapedparthaving apluralityoflimbs, eachlimb having aperipheralrecessedportioninwhichaprimaryelectricalcoilismountable, andatleastone secondarycoilismountable in piggyback on the primary electrical coil, one limb ofeach loopshaped part having a straight section. The frame also includes an adjustable attaching means for attaching one ofthe 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,thecentrallegbeingforreceiving amagneticcoredistinctfromtheattachingmeans. Theframeprovides ameans andamethodto efficientlysecureadjacentwindings inacircularcoretransformerkernel.

FIGURE 36

## WO 2011/060547

## Al 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 Published:

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



### 1 ELECTRICALTRANSFORMERASSEMBLY FIELDOFTHE 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. 

### BACKGROUNDOFTHE 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 ofthe 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 primaryand secondarycoils enlace acore made ofaferromagnetic alloy to create a path for a magneticfluxto circulate in a closed loop through both ofsaid coils. When an oscillating voltage is applied across the leads of the primary coil, it induces afluctuating magneticflux in the core which, by reverse effect, induces back avoltage across the lead terminals ofthe secondarycoil. The ferromagnetic property ofthe core allows an increase ofthe peak magneticflux density induced bythe coils in order to reduce the coils loop size and therefore to reduce the size of the transformer. The primarycoil ofadistribution transformer is on the high voltage side, and the secondarycoil is on the lowvoltage side. Morethan one secondarycoil may enlace the core to provide morethan one lowvoltage. 

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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 5to 30 kV, and the secondary voltage ranges from 110 volts to up to 480 volts. The coils and the coreform an interlaced assembly and are generallyattached 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) ofthe coils respectively to the power line and to the load. For purpose of clarity, the term "transformer kernel" in this document will 10 refertothe coils and core assemblywithoutthe 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. Asingle phase shell-type distribution transformer hastwo 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 athree-phase distributed voltage, and offers greater 30 coil reliability against lightning surges. Many manufacturers produce non-subdivided

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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 ofthe coils, often resulting in a requirementfora largertank. As making these connections is done manually, it is believed that the reliability can be increased byavoiding them, which also reduces the cost ofthetransformerwhile still providing acceptablevoltage regulation and circulating currentcharacteristics. 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 oraramid 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 formaking 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 sheetthicknesses ranging from 0.23to 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 transformerexciting current and core loss. The sheet musttherefore be positioned within the transformer core to have the rolled direction following the circulating path ofthe induced magneticflux. Priorto 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 ofthe steel is generallyperformed byannealing the preformed cores in batch foraprolonged time in afurnace atatemperature above

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Amorphous-steels are non-crystalline alloys formed by casting the melted alloy on the surface ofacooling 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 ofas-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 ofthe induced magnetic flux. Cores are conventionally batch annealed in afurnace atatemperature 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 difficultto handle and to assemblewith 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 efficiencyWO 2011/060547


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### ofthe transformerwill be the ratio ofthe outputted powerwith respectto the total of outputted powerand internal powerloss (core and coils). The distribution transformer power output capability is rated based on the temperature rise above ambient ofthe 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 atank or by external radiators attached to the plain tank. Heat removal from the transformer kernel must also take into accountthe
. transfer of heat from the interior parts of the kernel. Heat can be transferred by means of conduction, radiation, and convection. Ofall 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 heavierfluid. The hot oil will be cooled by convecting along the tanksurface and will go backto the bottom. An increase ofthe heattransfercan 20 be gained by creating ducts on or within the kernel, mainly in the coils, with one opening located nearthe bottom ofthe tank and another nearthe top for oil to flow through. This will increase the oil convective current by a chimney effect (or stack effect). Properchoice ofmaterial and sizing ofthe transformerkernel will have an impact on the transformer efficiency and rating. At equivalent transformer efficiencies, the significant subtracted core loss gained oversilicon-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 coilsWO 2011/060547


### 6 PCT/CA2010/001845

may become a problem for evacuation if proper heat transfer means cannot be provided from the interiorofthe coilstothe 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 numberofcoiled loops ofthe primary coil will establish the peak magneticflux in the magnetic path ofthe core and the ratio of coiled loops ofthe primary coil over the secondary coil will transform the inputvoltage to be outputted across the secondary 10 coil. The highvoltage primary coil is normally made ofseveral coiled loops arranged in stacked rows (in the presentdocument, a row is a numberofobjects arranged in a "straight line") ofa small conductor size covered by avarnish 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 normallywelded to the ends ofthe 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 mUltipleturns ofa continuous strip ofmetal sheet (rolled-up-uncut-core). Cut cores have significant disadvantages over uncut cores. Firstly, manufacturing of 30 cut cores involve a lot of labourfor cutting and forming, which increases transformerWO 2011/060547


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### costs. Secondly, an increase in transformer exciting current and power loss are associated with the presence ofjoints 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 arethe most expensive to produce, as they require, among otherthings: more cutting steps; aspecial 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 ofthe electrical coils around a limb ofthe magnetic core (cut or uncut), or inversely, by rolling up the metal strip around a limb ofthe 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 ofthem to occupy most of the circular window of the core. Accordingly, the electrical conductors are wound with a different number ofcoiled 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 ofconductors to fit within a circular boundary, and Winding an insulating sheet 30 between adjacent rows is not obvious as conductors would tend to packthemselves

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in adistorted mannerand breakthe row, especiallyatthe ends ofeach row nearthe edges ofthe 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 thatthey pile up at each coiled loop in the middle portion ofthe circulararea with the rows ofthe conductors ofthe 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 rectangularshape in orderto provide a rectangularwindow in the coils for rolling up asingle width continuous ferromagnetic metal strip. If necessary, a two-part rotating mandrel can be installed on the limb of the coils as asupportto easily roll upthe strip. A circular magnetic uncut core can be manufactured using a continuous single strip width ofa silicon-steel sheet or, ofan amorphous-steel ribbon. Forsilicon-steel, the complete core mustfirst be rolled up on asecond mandrel having the same diameter asthe one mounted on the coil limb and then annealed in afurnace. 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 significantstiffness, propercare 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 builtwith 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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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 easilytelescope ifallowed to slide atone end. Ifthe 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 anothermandrel ofa 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 Developmentfor 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 priorartanalyses, this method is believed to be impractical as the ribbon tends to breaktoo often during the transfer because ofits severe brittleness.
20 Another important aspect ofadistribution transformer kernel is its abilityto withstand ashort-circuitfault atthe outputofthe secondarycoil. During short-circuitconditions, 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 impairon the structural integrity ofthe coils ifthey 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 rectangularcross-section. Therefore, the coils must have 4 straight limbs delimiting a rectangUlar window for the core rectangular cross30 section to passthrough. Conductors and paperforming rectangularcoils lackthe selfWO 2011/060547
10 PCT/CA2010/001845

structural integrity required to withstand the repulsive forces. Strong inward forces will appearateach cornerofthe coils, which may causethe insulation atthe corners to fail if no adequate support is provided atthe corners. Support at the corner may be provided if the coils are firmly leaning against the core. A silicon-steel circular coremaybe strong enough to sustain the inward forces on its corners, butthis 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 arisk of de-lamination between the conductors/paper and the resin. Furthermore, cooling ofthe 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 solidlyfixed tothe enclosureviathe core. The practice isto 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 aframe for supporting both the coils and the corewithoutstressing 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 oftwo adjacentwindings 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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documentdoes not discuss the embrittlementofthe amorphous steel strip occurring after core annealing and the difficultyto 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 ofdifferentwidths and towind an insulating sheet between adjacent rows of conductors within a circular boundary. Additionally, no teaching is provided on howto make, locate and connectthe 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 ofthe rectangular coils as the document alleviates the problem by making these corners ofthe 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 transformerefficiency. SUMMARYOF THE INVENTION 20 Accordingly, it is an object of the present invention to proVide methods and apparatusto overcome at leastone drawbackofthe priorart. According to the present invention, there is provided asupportframe foran electrical transformerassembly, 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; andWO 2011/060547


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-an adjustable attaching means for attaching one of the loop-shaped parts with respectto the otherloop-shaped partand adjusting adistancetherebetween, so that only the straight sections are adjacent and form a central leg, the central leg being for receiving a magneticcore distinctfrom 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 partsto atransformertank. Preferably, according to afirst embodiment, the securing means comprises: -a baseframe; -first fixing means for fixing a bottom portion of the loop-shaped parts to the baseframe; and -second fixing meansforfixing the baseframe tothe transformertank. Preferably, according to anotherembodiment, the securing means comprises: -a baseframe; 20 -firstfixing means forfixing atop portion ofthe loop-shaped parts to the base frame; and -second fixing meansforfixing the baseframe tothetransformertank. Preferably, the securing means comprises alignment means for aligning the loopshaped parts with respecttothe baseframe. Preferably, the support frame further comprises handling means located on a top portion ofthe loop-shaped parts for handling and displacing the support frame from one location to another. 

### 30

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Preferably, according to anotherembodiment, the securing means comprises: -a baseframe; -first fixing means for fixing the handling means ofthe loop-shaped parts to the baseframe; and -second fixing meansforfixing the baseframeto thetransformertank. 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 ofthe channels having one inlet on one side of said 10 one limb and one outleton the otherside ofsaid one limb. Preferably, the channels form an angle with respect to the horizontal to produce a chimneyeffect 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 ofthe first chimneyand the second chimney, achimneyeffect in thefluids. 

### 20 Preferably, in one embodiment of the invention, the channels are formed by transversal grooves in the recessed portion ofthe 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 bythe adjustable attaching means such thatthe loop-shaped parts 30 are selectivelyseparated by afirst spacing distance and asecond spacing distance,

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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 interlockablefirst and second halfportions. Preferably, the mandrel furthercomprises oppositeflanges atextremities 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 memberhaving an inletand an outletforallowing circulation byachimneyeffect. According to the present invention, there is also provided a loop-shaped part of a supportframe ofan electrical transformerassembly, 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 piggybackon said primaryelectrical coil, one limbWO 2011/060547


### 15 PCT/CA2010/001845

of the loop-shaped part having a straight section, the peripheral recessed portion comprising: -a base portion forsupporting said primaryelectrical coil; -slanting sidewall portions extending from both sides of said base portion, said slanting portions comprising a plurality ofsteps 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 adjacentlyand transverselyto the coils, each ofthe 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 ofa step along a limb is increased by a length to accommodate said inletand outlet. Preferably, one ofsaid pluralityoflimbsfurtherprovides an tap inputopening on one side ofthe loop-shaped part, allowing connection ofatap tothe coils, once mounted, 20 and wherein a heightofastep along a limb is increased bya length to accommodate said tap inputopening. Preferably, predetermined steps are formed for bridging a lastcoil loop ofa rowwith afirst coil loop on an adjacent row. Preferably, the bridging is performed atcorners ofperpendicular limbs. Preferably, the loop shaped part comprises interlockable first and second half portions. 

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Preferably, one of said plurality of limbs further provides channels for conducting fluids adjacently and transverselyto the coils, each ofthe 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 areformed bytransversal groovestraversing the base portion and at leastone ofthe slanting sidewall portions. Preferably, a portfluidly 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 innersurface ofthe loop-shaped part atthe limbs perpendicularto said limb having the straightsection isflat. Preferably, a radius of curvature of the inner surface that is substantially semicylindrical is smallerthan 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 aframe 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 itselfalong afirst fold line according to an angle between 15 and 75 degrees such that said one end extends transversallywith respectto a plane where the coil liesto provide aconnection lead. Preferably, in one embodimentofthe 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 ofthe strip.

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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 straightsections, said coil assemblycomprising: -a primary electrical coil wound around said loop-shaped part, said primary electrical coil comprising first and second primary terminals at opposite ends ofsaid primarycoil, said first and second primaryterminals extending from the firstsidewall ofthe 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 secondaryterminals at opposite first and second ends ofsaid secondary coil, the first secondary coil terminal being formed by folding the first end ofthe strip over itselfalong afirst 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 thefirst and second primarysub-coil terminals extend, the second secondaryterminal being formed byfolding the second end ofthe strip over itselfalong a second 45 degree fold line to form afirst 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 ofthe strip extends in parallel with and outside said first and second sidewalls. According to the present invention, there is also provided a method ofassembling an electrical transformerkernel assembly, comprising the steps of: a) winding a primary electrical coil around a first loop-shaped part having a peripheral recessed portion along its outersurface for receiving the primaryelectrical coil, thefirst loop-shaped part having at leastone straightsection;WO 2011/060547


### 18 PCT/CA2010/001845

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 outersurfacefor receiving the primaryelectrical coil, the second loop-shaped part having at least one straightsection; 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 partsothatonlythe straightsections are adjacent and form acentral leg; 10 f) adjusting a distance between the first loop-shaped part and the second looped shaped partto afirstspacing distance; g) installing a mandrel around said central leg, said mandrel being sized to rotate freelyaround the central leg when the first loop-shaped part and the second looped shaped partare spaced bysaid firstspacing distance; and h) winding a metallic ribbon around the central leg to form a magneticcore, wherein thewinding step h) is distinctfrom the attaching step e). Preferably, the method furthercomprisesthe 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 thatthe 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 furthercomprises, 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) individuallytwisting each ofthe conductor loopsto form connection leads; cc) inserting insulating sleeves between adjacenttwisted conductor loops; andWO 2011/060547


### 19 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 firstwinding system forwinding a primary electrical coil around afirst loopshaped partand 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 parteachhaving at leastone straightsection; -a second winding system forwinding asecondaryelectrical 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 ofan adjustable attaching means, so thatonlythe straightsections are adjacentand form acentral 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 forwinding 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 containerfor containing a plurality of electrical transformer kernel assemblies assembled by the above30 described method.WO 2011/060547

20
BRIEF DESCRIPTION OF THE DRAWINGS PCT/CA2010/001845

Figure 1 is aschematicviewofatransformerkernel comprising acircularcore; 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 windowwhen theyare 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 windowwhen they are separated apart by spacers and leaning against the mandrel ofthe circular core; Figure 5shows rows ofconductors ofa primary sub-coil arrangement in asupporting 20 frame according to a preferred embodiment; Figure 6 shows rows of conductors of another primary sub-coil arrangement in anothersupporting frame according to anotherpreferred 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 7are associated; 

### 30WO 2011/060547
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Figure 9 is a schematic view of a cut cross section of a coil arrangement in a supporting frame ofa horizontal limb located outside ofthe core window; Figure 10 is a schematic view of a cut cross section of a coil arrangement in a supporting frame ofavertical limb located outside ofthe corewindow; Figure 11 is a perspective view of a supporting frame according to a preferred embodiment; 10 Figure 12 is a schematic drawing oftwo compressed rows ofconductors in a corner ofthe supporting frame of Figure 11; Figure 13 is a perspective cropped view ofthe supporting frame shown in Figure 11 showing how to coil a conductorfrom one row to the next according to a preferred embodiment; Figure 14 is a perspective cropped view ofthe supporting frame providing space for routing taps according to a preferred embodiment; 20 Figure 15 is a perspective view ofasupporting frame provided with skewed ducts for convecting oil toflowthrough according to a preferred embodiment; Figure 16 is a perspective view ofa supporting frame provided with horizontal ducts forconvecting oil to flowthrough according to anotherpreferred embodiment; Figure 17 is acutview ofasupporting frame shown in Figure 16; Figure 18 is a perspective view of two supporting frames assembled back-to-back and secured with attaching means; 

### 30WO 2011/060547

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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 apreferred 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 anotherpreferred embodiment; Figure 21 is a perspective viewfrom to viewing angles ofa base frame for receiving 10 two supporting frames assembled back-to-back; Figure 22 is aperspectiveviewofatwo partassemblyofasupporting 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 conductorcoil during winding ofsaid 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 electricalWO 2011/060547
23 PCT/CA2010/001845

connections between coils, and for locating a transformer kernel in a transformer tankwith electrical connections tothe bushings; Figure 28 is a schematic drawing showing a front view of the transformer kernel shown in Figure 27 in atank; Figures 29 A and B are schematic drawings ofan additional sequence involved for winding a conductor strip to form a coil around the supporting frame according to anotherpreferred embodiment; 

### 10 Figures 30 A to C are two front and perspective views respectively of a supporting mandrel for rolling-up a magneticstriptoform acircularcore; Figure 31 is a perspective view showing two coil arrangements assembled back-tobackand secured before installing the core mandrel; Figure 32 is a perspective view showing the installation ofthe core mandrel around the central leg oftwo coil arrangements assembled back-to-backand 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 atop view ofa 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 beforethe rolling up ofa magneticstrip around a mandrel installed around 30 the central leg oftwo coil arrangements assembled back-to-backand secured;

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### 10



### 20 Figure 36 is a perspective view from afirst angle showing a completed transformer kernel assemblyattached to a base on the bottom ofan oval tank; Figure 37 is a perspective view from a second angle showing a completed transformerkernel assemblyattached to abase frame on the bottom ofan oval tank; Figure 38 is a perspective view from athird angle showing a completed transformer kernel assemblyattached to a baseframe; Figure 39 is a perspective viewfrom athird angle ofa 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 aseries ofback-to-backcoil arrangements and three circularcores. Figure 41 is a perspective view ofa container used for storing and shipping multiple transformerkernels; 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 OFTHE PRESENT INVENTION Differentpreferred objects ofthe present invention will nowbe presented.

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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 formass production and is ofminimal cost. US patentapplication number 61/262,603 discloses a new system and method fortreating 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 uptoform circularcores showing lowcore 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 offurnace annealed core which renders the manufacturing of circular-uncut core distribution transformers possible and costeffective. 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. Anotherobject ofthe present invention is to provide adistribution transformer kernel having acircularcore which can be massivelymanufactured at lowcost.WO 2011/060547


### 26 PCT/CA2010/001845

Accordingly, the present invention provides a method to efficiently coil and stack differentwidths of rows ofconductors and wind an insulating strip between adjacent rowswithin a recess having acurved 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 supportthe coil and the core ofacircularamorphous-steel coretransformerkernel. Accordingly, the present invention also further provides a transformer kernel which can be efficientlyenclosed and fixed in asmall 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 thetankbushings. Accordingly, the present invention also further provides a means and a method to 20 efficientlysecure an amorphous steel circularcoretransformerkernel into atank. Accordingly, the present invention also further provides a means and a method to efficiently remove heat generated within the coils ofa circular amorphous-steel core transformerkernel. 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.WO 2011/060547


### 27 PCT/CA2010/001845

Accordingly, the present invention also further provides a means and a method to efficientlywind aconductoron acoil frame and to make, locatethe 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 atransformerkernel. 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 atransformer kernel that can be efficientlyenclosed in an oval enclosure ortank. 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 coilarrangements 3. Preferably, the coil-core arrangement lies with the circularcore central axis in avertical position. Each rectangularcoil arrangement 3 comprises an innerprimary sub-coil 5 and an outersecondary 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. Figure2 shows a cutview ofa limbfrom one ofthe 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 outerwall 11 ofthe supporting frame 9 has an arc shape. The inner walls 13 of the supporting frame 9 are arranged in a 30 series ofsteps 8 to provide a recess to accommodate the rows ofsmall conductors

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### 28 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 atthe deepest partofthe recess and the last one being wound on top ofthe coil. The thickness along the innerwalls 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 ofthe primary sub-coil 5 are arranged in rows preferably separated by a thin electrical insulating layer 17 ofa material such as paper, epoxy coated paperor 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 athin 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 heightofeach step 8 is equal to the sum ofeach row's heightfacing the step. On top ofthe last row ofconductors, there is athicker electrical insulating row 19 preferably madewith several coiled loops ofathinner insulating strip such as astrip ofpaper, epoxy coated paperor poly-aramid, and extending on each side overthe supporting frame. The junction between the thicker dielectric row 19 and the sides 21 of the supporting frame 9 represents atracking path yielding lowerdielectric 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 outerwall 11. A conductorstrip 27 adjoined to athin insulating strip preferablyWO 2011/060547


### 29 PCT/CA2010/001845

made of paper, epoxy coated paperor poly-aramid, and which is slightly widerthan the conductorstrip 27 is simultaneously coiled in piggyback overthe 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 fitwithin a half-disc shape. The arc shape ofthe outer wall 11 of the coil frame is chosen to have a radius smaller or equal to the inner radius ofthe 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 ofthe 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 ofconductors 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 oftwo coil arrangements positioned back-to-back within the window opening of a circular core (the coil 20 portions outside ofthe core are not shown). The two backto back limbs are leaning against each other in order to create the gap 35 which allows the mandrel 31 to rotatefreely in orderto be ableto roll upthe amorphous in-line annealed alloy ribbon on the mandrel to form the circularcore 1. Referring nowto Figure 4, there is shown azoomed viewofthe central portion ofthe core with the two half-disc limbs of the two coil arrangements now separated by insulated spacers 37. The half-disc limbs ofthe two coil arrangements are separated apartand are immobilized by each leaning attheir midpoint 36 againstthe innerwall ofthe core mandrel 31. The insulated spacers 37 are placed between the two back30 to-backcoil arrangements to maintain agap and to create opening ducts 39foroil to

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### 30 PCT/CA2010/001845

flowthrough in orderto cool the conductors. Two openings 41 forming ducts on each side ofthe secondarycoil are also availableforoil to flowthrough in orderto cool the coils. Preferably, the circular core lies in the transformertank 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 forthe transformer kernel in the tankforthe 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. ofthe conductor in rows increasing inwidth as they are. stacked raises the problem of having to route the coiled conductorfromone 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 ofthe first row to the left end and then, is switched to the next upper row as shown bythe curved arrow at the end ofthe row. The conductor is then coiled from left end to the right end ofthe 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 atthe end ofsome rows in orderto bring the conductor underthe 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 atthe end ofthe rowto provide asafe 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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from one rowto the next. The first rowofconductoris coiled from starting location 24 at the right end ofthe 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, isverticallyswitched to the next upper rowto be coiled as shown by the curved arrow at the end of the extending row. When required, a narrowstrip of insulating material 28 can also be added atthe end ofthe rowto provide asafe tracking distance between the first coiled loop ofa row and the last coiled loop ofthe next upper row where the voltage between two conductors of 10 adjacentcoiled 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 ofvoltage 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 intermediatevoltage 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 aretwo leads at both ends ofthe sub-coil which areWO 2011/060547
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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 avoltage pointto a lead ofa primary sub-coil will impact on the dielectric thickness ofthe 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 ofthe leads tovoltage points V1 to V8 shown in Figure 8 represent apreferred embodiment. Using the schematic of Figure 7 and referring to Figure 8: Preferably, the lead extending from conductor loop 51 ofthe 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 ofthe HVa and HVb sub-coils are connected to pointV2. 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 pointV2. Since the voltage pointV2 is at about halfofV3, the thickness ofthe 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 pointV1 is lowerthan V3, the dielectric portion ofthe 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 ofthe present invention, proper voltage insulation is provided between loops of conductors and the core, in 30 orderto withstand high voltage impulsetests.WO 2011/060547
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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 L

V1 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 L V2b 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 ofeach coil arrangement 3 shown in Figure 1 will be at the lowestvoltage, asV4 is normallyconnected to the ground voltage reference (this is generallythe case forthe 

### 120/240Vsecondary coils ofa distribution transformer). In the casewhere thetransformeronly has one secondarycoil, 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 towithstand high voltage impulse tests. Referring nowto Figure 9, a cross section ofthe top and bottom horizontal portions ofthetwo coil arrangements 3thatare located outside ofthe core windowopening is 20 shown. The outline ofthe cross section for the supporting frame is not constrained by the circular shape ofthe window opening. In Figure g, the wall ofthe supporting frame g can be made thickerto 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 ofthe core 1. Forthe top and bottom horizontal portion of the coil arrangements shown in Figure 1, the bottom boundary 75 ofthe 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 boundarycan be efficiently used to create aflat 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 windowWO 2011/060547

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opening is shown. The bottom portion of the supporting frame can also have a straight boundary72 or itcan be extended to adoptacurved shape 77 as it needsto 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, thetwo side boundaries 79 are straightand 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, 9and 10. The limb 87 is extruded according to the outline ofthe cross section of Figure 5 and the limbs 83 and 85 are extruded according to the outline ofthe cross section shown in Figure 9. As forthe limb 89, it is extruded using the straight boundary 72 of Figure 10. Forall four limbs, the walls 13 ofthe recessed portion ofthe 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 ofthe supporting frame is an extrusion revolving around the innercornerwhere the limbs are meeting to provide a series ofsteps 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 ofthe primary coil to oil in order to cool the conductors. The switching of the conductor loop 15 of the primarysub-coil from one rowto the next, the overlapping ofeach insulating layer 17 coiled over each row, and the output leads forthe primary and secondary sub-coilsWO 2011/060547


### 35 PCT/CA2010/001845

are all located on one ofthe three limbs ofthe coil arrangement situated outside of the corewindowopening. When coiling the conductor 15 ofa row overan 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 ofthe supporting frame. Referring now to Figure 12, if the primary sub-coil is coiled with a round conductor, the coiled conductorwill naturally position itselfon the small recess appearing on the insulating layerbydeformation 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 rowswill be smallerby a Evaluewhich is dependanttothe conductorcoiled 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 corneras shown in Figure 12. Accordingly, the step height 8 is gradually reduced from both ends ofthe 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 dependenton the numberofrows 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 properfilling ofeach row in the recess portion ofthe 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 ofthe 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 ofthe supporting frame, one hole aligned with the flat surface ofthe recessed portion to start the coiling the firstWO 2011/060547

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row, and the otheraligned with the lastcoiled 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 ofthe coil. Alternatively, the lead on the last coiled row can exit between the coil frame edge 86 andthe insulating layer 19 through insulating papersleeves. Referring to Figure 14, the edges 86 on top of the supporting frame could extend overthe last row ofconductorsto provide aspace 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 allowconnections to atap selector. The secondary sub-coils 7 as shown in Figure 1 have significant outer surface portions available foroil convection cooling within the transformertank. This includes the portion located within the core window opening. Forthe 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 ofconductors 15. Referring backto 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 ofthe steps 8 on both sides ofthe spacers are increased. Two ramp-up spacers 113 and 114 could also be used to smooth the elevation ofthe 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 ofthe supportingWO 2011/060547
37 PCT/CA2010/001845

frame to create the chimney effect. Each duct has an opening for oil to get in orto getout. Oil entering from the bottom ofthetank is guided up bythe 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 effectand therefore the oil flow for better cooling. With the provided ducts, heat can be evacuated from the conductors ofthe primary coil located in the core window opening, by using the high thermal conductivity ofthe conductors themselves to carry the heat out to the location ofthe 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 10and 11 thatwill allowflowing 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 stepsfrom theflat bottom surface ofthe recessed portion ofthe 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 ductto create aconvecting flowofoil bychimneyeffect. Referring back to Figure 11, the supporting frame of the present invention further comprises protuberant portions 84 located atthe top and bottom on each side ofthe 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 togetherto form a unique rigid structure. Positioning the nuts onWO 2011/060547


### 38 PCT/CA2010/001845

the rods allows adjustmentofthedistance between thetwoframes. 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 bollardsto ease lifting and handling ofthe assembly. The supporting frame ofthe 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 ofthe supporting frame. These protuberant portions 117 comprise an opening perpendicularlyaligned with abase plane 121 forsecuring the assembled supporting frames to thebase with nuts screwed on athreaded 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 ofatransformertank onto which the elevating threaded rods are fixed on by means ofaweld. 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 togetherto provide a rigid levelled surface 127to supportthe frame assembly and openings 129for holding bolts foranchoring the support frame attaching means. The base frame also comprises nipples 131 formed underthe 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 ofWO 2011/060547
39 PCT/CA2010/001845

supporting the coils and the core in the tank without transmitting mechanical stressestothem. 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 ofthe first halfsupporting frame 134 into the female portion 135 ofthe second half supporting frame 136. This mating junction provides a tracking path at least threetimes superiorto the insulating thickness nearthejunction once the two halves are assembled. A proper bindercompatible 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 atwo part mould afterwhich openings such as openings 88 are simplydrilled. The description ofthe supporting frame being complete, thefollowing 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 transformercoil, and howan 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 ofthe ribbon can be assembled in afully 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 motordrive. 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 largerthan the conductor strip. Each material feeder is provided with a robot manipulating arm 30 and a cutting actuatorto bring, engage, wound and cut the material on the rotatingWO 2011/060547
40 PCT/CA2010/001845

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 ofthe supporting frame. The conductor is then wound for a predetermined number ofturns On a single layerto 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 ofthe 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 

### 142which is then dressed with an insulating sleeve and bent on the side ofthe 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 ofthe supporting frame associated to a left-coil or a right-coil arrangement, whichever is being wound. The next step will be the winding ofthe secondary sub

### 30 coil.

### wo 2011/060547
41 PCT/CA2010/001845

The winding of the secondary sub-coil consists of winding both an insulating and conductorstrip overtheprimary sub-coil ofoverall rectangularshape. 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 ofthe strip to form a right angle exit. In the present invention, the robot manipulating arm includes means to fold and shapethe extremityofthe strip 194. Figure 25, sequencesAto Eshowwith schematicviews the steps involved to fold and wind the conductorstrip 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 ofthe drawing in each sequence shows atop view ofthe supporting frame being wound with the conductorfoil and the insulating strip arriving overthe supporting frame which is rotating clockwise with reference to the right drawing showing the supporting frame from afront 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 identifierwill 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 dielectricthickness is obtained, the lead ofthe 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 transverselyto the coil. Then, the length ofa lead must be sufficiently long to allow connection to a transformer tank bushing with further upward folding, ortothe exit lead ofanothercoil. 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 ofthe 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 ofWO 2011/060547
42 PCT/CA2010/001845

the description, the strip isfolded along a45 degreesfolding line. In sequence B, the folding line 201 ofthe strip 194 is broughton top ofthe supporting frame limb where the exits leads 197and 198are located. Both conductorstrip 194and insulating strip 195 are then wound simultaneously foran appropriate numberofturns. 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 oftravel ofthe strip being wound. The location ofthefolding 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' showcompleted left-coil and right-coil arrangements. Figure 26, sequences A to 

### J show with schematic views the steps involved to fold and wind the conductorstrip 194with insulating strip 195to formtwo secondarysubcoils 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 adashed line and the identifierwill include an additional superscript mark ( ,). Priorto starting the winding ofthe conductorstrip 194, a thick insulating layer 19 is built by winding multiple turns with the insulating strip 195. Oncethe desired dielectricthickness is obtained, the lead ofthe 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 simultaneouslyforan appropriate numberofturns. In sequence 30 C, the conductor foil 194 is cut and the trailing end is folded twice along two 45WO 2011/060547

43 PCT/CA2010/001845

degree folding lines 154 (154') and, 155 (155') on the same side (opposite side fora 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 ofthe 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, afew 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 oftravel ofthe 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 Fwill 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 simultaneouslyfor an appropriate numberofturns. In sequence H, the conductorfoil 194 is cutand the trailing end isfolded twice on the opposite sidetothe primarysubcoil 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 respectto the direction oftravel ofthe strip. The location ofthe folding line 160 on the strip 194 has been chosen in orderto arrive on top ofthe limb ofthe 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 thenWO 2011/060547


### 44 PCT/CA2010/001845

completed. To finalize the winding ofthe coil arrangement, a few extra turns ofthe 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 

### 156with 

### 156', 159 with 

### 159', and 

### 162with 

### 162' aligned towards each otherwith 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 secondarysub-coils. In the case ofasingle 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 limbformed bythe backto-back coil arrangements to form acircularcore 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 bestsuited 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 lowvoltage 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 wouldWO 2011/060547
45 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 tothe bushing by an upward folded strip segmentthat may have been welded on the lead, orwhich is realized byfurther folding the leads that were extending further away from the coils when they were wound in Figures 25Ato E' or26Ato J'. In cases where the conductorfoil 194 produces bulky leads that are

### too large when folded, the winding sequences Figures 25 A to E' or26 A to 

### J' may incorporate an 10 additional folding step as shown in Figure 29A. Thewidth ofa 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 arrangementwith narrowerleads 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-backcoil arrangement. Figures 30Ato 30C showa mandrel assembly for rolling up a ribbon. It comprises two walls 230 and 231 each having an arc shape ofa predetermined internal radius and athickness, 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 theywill form a cylindrical tube having the given internal radius and given height. The walls ofthe mandrel are preferably made ofa pressed or moulded rigid inSUlating material, although stainless steel or any non-ferromagnetic material having good structural rigidity cOuld also be used. Both ends ofthe walls have a half discflange 170 such that when the two walls are snapped, a mandrel with flanges is formed. A bindercan also be used tofuse thetwo walls and flangestogether. 

### 30WO 2011/060547
46 PCT/CA2010/001845

Referring to Figure 31, completed left-coil and right-coil arrangements 199 and 200 are put back-to-backand secured togetherwith thethreaded, rods 115, nuts 119 and washers 117. The nuts 119 are positioned on the threaded rods 115 such thatwhen the coil arrangements are pushed towards each other, the two arc shaped back to back limbsfitwithin a circularoutline as shown in Figure 3and 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 greaterthan the outer radius ofthe circular outline ofthe two backto backarc shaped limbs and its height is slightlysmallerthan the heightofcoil 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 leastthree 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 centeraxis 

### (Xo,Yo ). Three narrow rollers 234 can be used on each flange 237 of both sides of the mandrel to clearthe access ofthe middle portion ofthe mandrel forthe ribbon. The angular distance between rollers can be different as long as they are localized over an angle greaterthan 180 degrees to keep the mandrel from getting out ofthe axis of rotation. The internal distance between theflanges 236 ofthe rollers 234from one side ofthe mandrel tothe other isjustwide enough to allowthe width ofthe mandrel to fit in between to maintain its axial position in orderto avoid frictional contact with one ofthe 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, atWO 2011/060547 

### 47 PCT/CA2010/001845

least one ofthe 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 ofthe circularlimb centeraxis'

### (Xo,Yo ). Ifgreaterprecision is needed, each rollercan successively push on the mandrel until it leans againstthe 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 ofthe 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 supportto 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 arewelded 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 supplyof ribbon can be provided by bringing a filled reel in rotation in proximity ofthe 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 ofa ribbon toform cores oftransformer 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 tothe mandrel while the completed transformerkernel is moved away. Figures 36 to 38 showafinal transformerkernel assembled according to the present 30 invention. Insulating sleeves 240 have been added around the primary coil externalWO 2011/060547


### 48 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 arrangementfurther comprising bracing members 243 and 244 that are held againstthe 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 aflow of cooling fluid near the top and bottom surface ofthe secondary coils. The bracing members will increase the transformer abilityto 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 primaryand secondary sub-coils from separating apartdue tothe repulsiveforces created bythe short-circuitcurrents 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 transformeras 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 usingWO 2011/060547


### 49 PCT/CA2010/001845

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 ofthe transformer. Referring to Figure 41, core-coil arrangements produced with the system ofthe present invention can be grouped in rows on a on a rack 252 and multiple racks 252 containing a numberofcoil 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 forsupporting a group ofcore-coil arrangements and atop means 255 forsecuring the group ofcore-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 transformerkernel manufacturertotransformerassemblers. 20 Referring to Figure 42, a distribution transformerfinal assembly comprising an oval tankwhich is capable of enclosing the transformer kernel ofthe present invention is shown. Such a distribution transformerwill have a centre ofgravity located closerto 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 orspiritofthe present invention.WO 2011/060547

WHAT IS CLAIMED: 

### 50 PCT/CA2010/001845

1. A supportframe foran electrical transformerassembly, 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 respectto the other loop-shaped partand adjusting a distance therebetween, so that only the straight sections are adjacent and form a central leg, the central leg being for receiving a magneticcore distinctfrom the attachingmeans. 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 forsecuring the loop-shaped partsto atransformertank. 

### 20 4. The support frame according to claim 3, wherein the securing means comprises: -a baseframe; -first fixing means for fixing a bottom portion of the loop-shaped parts to the base frame; and -second fixing meansforfixing the baseframe to thetransformertank. 5. The support frame according to claim 3, wherein the securing means comprises: -a baseframe;WO 2011/060547
51 PCT/CA2010/001845

-firstfixing means forfixing atop portion ofthe loop-shaped parts to the base frame; and -second fixing meansforfixing the baseframetothetransformertank. 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 baseframe.
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 supportframe from one location to another. 8. The support frame according to claim 7, wherein the securing means comprises: -a baseframe; -first fixing means for fixing the handling means of the loop-shaped parts to the baseframe; and -second fixing meansforfixing the baseframetothetransformertank. 20 9. The support frame according to anyone ofclaims 1 to 8, wherein a selected one ofsaid pluralityoflimbs otherthan those forming the central leg further provides channels for conducting fluids adjacently and transversely to the coils, each ofthe channels having one inlet on one side of said one limb and one outlet on the other side ofsaid one limb. 10. The supportframe according to claim 9, wherein the channels form an angle with respectto the horizontal to produce achimney effect in thefluids.
11. The supportframe according to claim 9, further comprising afirst chimney for 30 enclosing the inputs ofthe channels, the first chimney having a closed top and an

### wo 2011/060547


### 52 PCT/CA2010/001845

open bottom, and a second chimney for enclosing the outputs ofthe channels, the second chimney having a closed bottom and an open top, to produce, by means of the firstchimneyand the second chimney, achimneyeffect 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 supportframe according to anyone ofclaims 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 bysaid 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 interlockablefirstand second halfportions.WO 2011/060547


### 53 PCT/CA2010/001845

17. The support frame according to anyone of claims 14 to 16, wherein the mandrel further comprises oppositeflanges atextremitiesthereof. 18. The supportframe according to anyone ofclaims 1 to 8, furthercomprising at least one bracing member mountable on an external surface of at least one of said limbs otherthan 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 bysaid at leastone bracing member having an inletand an outlet forallowing circulation byachimneyeffect. 20. A loop-shaped part of a supportframe 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 secondarycoil being mountable in piggybackon said primary electrical coil, one limb 

### 20 of the loop-shaped part having a straight section, the peripheral recessed portion comprising: -a base portion forsupporting said primaryelectrIcal coil; -slanting sidewall portions extending from both sides of said base portion, said slanting portions comprising a plurality ofsteps 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 cornerbetween adjacent perpendicularlimbs isgradually reduced. 

### 30WO 2011/060547



### 54 PCT/CA2010/001845

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 ofthe channels having one inlet on one side ofthe loop-shaped part and one outlet on the other side ofthe loop-shaped part and wherein a height of a step along a limb is increased bya length to accommodate said inletand 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 bya length to accommodatesaid tap inputopening. 24. The loop-shaped partaccording to claim 20, wherein predetermined steps are formed forbridging a lastcoil loop ofa rowwith afirst coil loop on an adjacent row. 25. The loop-shaped part according to claim 24, wherein said bridging is performed atcorners ofperpendicular limbs. 26. The loop-shaped part according to anyone of claims 20 to 25. wherein the loop shaped part comprises interlockablefirstand second halfportions. 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 ofthe channels having one inlet on one side ofthe loop-shaped part and one outlet on the other side ofthe loop-shaped part, and wherein the channels areformed bytransversal grooves traversing the base portion and at leastone ofthe slanting sidewall portions. 28. The loop-shaped part according to claim 27, wherein a port fluidly connects the inletsto the transversal groovestraversing the base portion. 30WO 2011/060547

55 PCT/CA2010/001845

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 perpendicularto said limb having the straightsection isflat.
30. The loop-shaped part according to claim 29, wherein a radius of curvature of the innersurface that is substantially semi-cylindrical is smallerthan an inner radius ofacylindrical core mountable around said loop-shaped part. 10 31. An electrical coil assembly comprising an electrical coil and a frame onto which the coil iswound, made ofan electrical conductorstrip having afirst 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 transversallywith respectto aplane where the coil lies to provide aconnection 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 or32, wherein said oneend 20 folded over itself is further folded along a second fold line parallel to a longitudinal axis ofthe 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 straightsections, said coil assemblycomprising: -a primary electrical coil wound around said loop-shaped part, said primary electrical coil comprising first and second primary terminals at opposite endsWO 2011/060547


### 56 PCT/CA2010/001845

ofsaid primarycoil, said first and second primaryterminals extending from the firstsidewall ofthe 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 secondaryterminals atopposite first and second ends ofsaid secondary coil, the first secondary coil terminal being formed by folding the first end ofthe strip over itselfalong afirst 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 thefirst and second primarysub-coil terminals extend, the second secondaryterminal being formed byfolding the second end ofthe strip over itselfalong a second 45 degree fold line to form afirst 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 ofthe strip extends in parallel with and outside said firstand 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 outersurfacefor receiving the primaryelectrical coil, thefirst loop-shaped part having at leastone straightsection; b) winding a secondary electrical coil on piggyback on the primary electric coil around thefirst loop-shaped part; c) winding a primary electrical coil around a second loop-shaped part having a peripheral recessed portion along its outersurfacefor receiving the primaryelectrical coil, the second loop-shaped part having at leastone straightsection; d) winding a secondary electrical coil on piggyback on the primary electric coil around the second loop-shaped part;WO 2011/060547

57 PCT/CA2010/001845

e) attaching the first loop-shaped part with respect to the second loop-shaped partsothat onlythe straightsections are adjacentand form acentral leg; f) adjusting a distance between the first loop-shaped part and the second looped shaped partto afirstspacing 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 partare spaced bysaid firstspacing distance; and h) winding a metallic ribbon around the central leg to form amagneticcore, wherein the winding step h) is distinctfrom the attaching step e). 

### 10 36. The method according to claim 35, furthercomprising 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 thatthe 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 ofconductor loops with the primary electrical coil at distinct predetermined turncounts; bb) individuallytwisting each ofthe conductor loopstoform connection leads; cc) inserting insulating sleeves between adjacenttwisted conductor loops; and dd) bending said leads transversally with respect to the winding of the primary electrical coil. 38. Asystem forassembling an electricaltransformer kernel assembly, comprising: -a first winding system forwinding a primary electrical coil around a first loopshaped partand second loop-shaped part respectively, each loop-shaped part 30 having a peripheral recessed portion along its outer surface forreceiving theWO 2011/060547



### 58 PCT/CA2010/001845

primary electrical coil, the first loop-shaped part and the second loop-shaped part each having at leastone straightsection; -a second winding system forwinding asecondaryelectrical 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 thatonlythe straightsections are adjacentand 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 forwinding a metallic ribbon around the central leg to forma magnetic core, the core being distinct from the adjustable attaching means. 39. The use ofthe method as claimed in claims 35 to 37 to manufacture electrical transformerkernel assemblies in series production. 20 40. A storage container for containing a plurality of electrical transformer kernel assemblies assembled bythe method ofclaims 35to 37.""02011/06054'1 

### '\147

### PC1'/C~2010/001S45

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SUBSTITUTE SHEET (RULE 26)INTERNATIONAL SEARCHREPORT InternationalapplicationNo. PCT/CA20101001845 A CLASSIFICATIONOF SUBJECTMATTER IPC: H01F41/08 (2006.01), H01F27/02 (2006.01), H01F27/06(2006.01), H01F30/16(2006.01) AccordingtoInternationalPatentClassification(IPC)ortobothnationalclassificationandIPC B. FIELDS SEARCHED Minimumdocumentation searched (classificationsystemfollowed byclassificationsymbols) IPC: HOIF41/08 (2006.01), HOIF27/02 (2006.01) HOIF27/06 (2006.01) HOIF 30/16 (2006.01)
Documentationsearchedotherthanminimumdocumentationto theextentthatsuchdocuments areincludedinthefields searched

Electronicdatabase(s)consulted duringtheinternational search(nameofdatabase(s) and, wherepracticable, searchtermsused) Epoque Epodoc,US FullTxtdatabase: IEEE, CanadianPatentDatabase (Keywords transformerassembly, loop, limbs, legs,recessed, fibreglass, epoxy, paper, cardboard, wood, composites, supportframe, basefi:ame, distributiontransformer) C DOCUMENTS CONSIDEREDTOBERELEVANT CategOlY* Citationofdocument, withindication, whereappropriate, oftherelevantpassages A EP318322 (Book) 31 May 1989 (31-05-1989) (seewholedocument) A .TP2009188034 (FutaietaL) 20August2009 (20-08-2009) (seewholedocument) A GB126,271 (Holslag) 15 March 1920 (15-03-1920) (seewholedocument) A US 4,781,348 (CutforthetaL) 1November 1988 (01-11-1988) (seewholedocument) A US 3,686,561 (Spreadbmy)22August 1972 (22-08-1972) (seewholedocument) A EP518,565 (AllanetaL) 16December 1992(16-12-1992) (seewholedocument) Relevantto claimNo. 1-40
1-40
1-40
1-40
1-40
1-40

[ ] FurtherdocumentsarelistedinthecontinuationofBoxC. Specialcategoriesofciteddocmnents ")"." dOCUlllt:;l1tde±1ningthegeneralstateofthe 3rtwhichisnotconsidered tobe ofpartIcularrele,\Tance "E" earlierapplicationorpatentbutpublishedonorat1erthe international filmg date "L"' document"\I'hichmaythrm:vdoubts onpriorityclaim(s) or,'.'hichis CItedtoestablIshthepublIcatIondate ofanotherCItatIonorother specwlreason (as specdied) documentreferringto anoraldisclosure, use, exhibitionorothermeans "P" documentpublishedpriorto the internationalfiling datebutlaterthan thepnont:vdate claImed Dateofthe actualcompletionoftheinternational search 8February2011 (08-02-2011) Name andmailingaddress oftheISAICA CanadiallhltellectualPropertyOtlice PlaceduPortageI, C114- 1stFloor,BoxPCT 50Victoria Street Gatineau, QuebecKIAOC9 FacsimileNo. 001-819-953-2476 FormPCTIISAl210 (second sheet) (July2009) [X] Seepatenttinnilyalmex. "T" laterdocmnentpublisheda±1erthe internationalfiling dateorpriority date andnot111 con11Ict"\'liththeapl)hcatIonbutciteatounderstand

- thepnnciple ortheorylUlderlY111gtle 111\ientIon C"X" documentofparticularrelevance', theclaimedinventioncmmotbe conSIderednovelorcannotbeconslderedto 111volvean 111ventIve step ';vhenthedoclUllentis takenalone c.ycc docmnentofpartIcularrelevance. theclallned111ventlOnemmotbe conSIderedtoIl1\/Olve 3n111\ientI,,-'e stepyvhenthedocument lS comb111edYVlthoneormoreothersuchdocuments, suchcombination beingobviousto apersonskilledinthe 3rt "&" documentmemberofthe samep3tentfamily Dateofmailingoftheinternational searchreport 10FeblUaIy2011 (10-02-2011) Authorizedotlicer Camran Syed (819) 934-4550

Page201'3INTERNATIONAL SEARCHREPORT Informationonpatentfamilymembers InternationalapplicationNo. PCT/CA2010/001845 PatentDocument CitedinSearchReport EP0318322Al Publication Date 31 May 1989 (31-05-1989) PatentFamily 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) 29May 1989 (29-05-1989) 13 FebruaIy 1990 (13-02-1990)
JP2009188034A
GB126271A
US4781348A
US3686561A

EP0518565Al 1995) 20 August2009 (20-08-2009) None
15March 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 16December 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) 04FebruaIy 1975 (04-02-1975) 08December 1972 (08-12-1972) 06August 1976 (06-08-1976) 26FebruaIY 1975 (26-02-1975) 10August 1973 (10-08-1973) 03 December 1977 (03-12-1977) 30November 1978 (30-11-1978) 25 October 1972 (25-10-1972) 29November 1972 (29-11-1972) 14December 1995 (14-12- 04Apri11996 (04-04-1996) 09 October 1997 (09-10-1997) 02 JanuaIy 1998 (02-01-1998) 18December 1997 (18-12-1997) 12March 1998 (12-03-1998) 08November 1995 (08-11-1995) 15March 1995 (15-03-1995) 28 June 1995 (28-06-1995) 12November 1997 (12-11-1997) 15March 1995 (15-03-1995) 28 June 1995 (28-06-1995) 03 September 1997 (03-09-1997) 15 July 1992 (15-07-1992) 20JanuaIy 1993 (20-01-1993) 10JanuaIy 1996 (10-01-1996) 04JanuaIy 1995 (04-01-1995) 17May 1995 (17-05-1995) 10JanuaIy 1996 (10-01-1996) 31 July 1991 (31-07-1991) 28 June 1994 (28-06-1994) 07FebruaIy 1995 (07-02-1995) 03 October 1995 (03-10-1995) FormPCTIISAl210 (patentfamIlymmex) (July2009) Page 3 01'3