Metal encapsulated multi-phase high voltage switching system filled with compressed gas

A metal enclosed multi-phase high voltage switching arrangement filled with compressed gas and provided with an interior protective wall between the bus bar chamber and the switch chamber. The electrical connection between the two chambers is established via gas tight passages or passthroughs arranged diagonally in the protective wall, with the passages being disposed, in one direction, at the spacing between the bus bars and, in the other perpendicular direction, at the spacing of the poles of the high voltage power or load switch in the switch chamber. Straight connections without crossovers are provided in the bus bar chamber between each bus bar and the associated passage via the respective disconnect or three-way position bus bar switch, while the connecting lines in the switch chamber from the passages to the respective poles of the high voltage switch extend in mutually parallel planes, here again without cross-overs.

BACKGROUND OF THE INVENTION 
The present invention relates to a metal encapsulated or enclosed 
multi-phase high voltage switching system filled with compressed gas for 
single or multiple double bus-bar systems. 
More particularly, the present invention relates to a switching system of 
the above-type which is provided with protective walls, equipped with 
passages, for gas-tightly partitioning the system into the following 
protected chambers: (1) a switch chamber including a high voltage switch 
in the form of a power or load break switch, and cable terminals 
electrically connected with the switch and penetrating the enclosure or 
encapsulation; and (2) a bus bar chamber for each bus bar system 
accommodating the respective bus bars and a respective disconnect or 
three-way switch for each phase connected with the bus bars. Moreover, the 
protective walls of the switching system are also provided with 
bushing-type current pins which extend through the passages to 
electrically connect the two protected chambers, and the poles of the 
power or load switch are arranged next to one another in a straight line 
or slightly offset with respect to the front of the switching system. 
A system having the above features is known under the name "Steel Sheet 
Protected, SF6 Insulated Switching System Series ZV2" and is described in 
Publication No. 1376/14 of Color-Emag ElecktizitAts-Aktiengesellschaft of 
Ratingen, Federal Republic of Germany, and is composed of a plurality of 
block-shaped modules which are closed in themselves and are thus separated 
from one another. The modules each include an operational chamber, e.g. a 
bus bar chamber. To be able to assemble a complete switching system, the 
modules of several operational chambers must be combined through the 
intermediary of gas-tight passages. 
In view of the use of block-shaped housings, the known switching system 
makes it possible to encapsulate or enclose its simple framework in planar 
sheet metal. To be able to reliably manage the pressures developing during 
operation or in case of malfunction, without having to make the metal 
sheets of the encapsulation too thick, these metal sheets are reinforced 
by additional measures, e.g. ribs welded to their interior or exterior 
faces. 
In the known system, the block-shaped housing modules make it possible to 
arrange all three bus bars of a system in a plane parallel to the closest 
covering. Since the bus bar disconnect switches also provided in this 
module are oriented phase by phase according to the poles of the power 
switch, the connecting lines between the bus bars and the disconnect 
switch poles are intertwined and cross over one another. Thus the bus bar 
chambers have a relatively great depth and, for that reason, they are 
disposed above or below the switch chamber. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a high voltage system 
of this type which has the most compact structure and short, simply 
configured connecting lines so that the entire system is improved and more 
economical in configuration and manufacture. 
This is accomplished in a system of the type having the features initially 
described above by providing that: 
(1) in each bus bar chamber the electrical connection between the bus bar 
and the bushing-type current pin in each phase is effected in a straight 
line and at least approximately at a right angle to the axis of the bus 
bar, and with the respective straight line electrical connections being in 
mutually parallel planes; 
(2) the passages in the protective wall are staggered diagonally in such a 
manner that the center lines of their bushing-type current pins in one 
direction are spaced at a distance equal to the center-to-center spacing 
of the bus bars and in the other (lateral or perpendicular) direction at a 
distance equal to the center-to-center spacing of the poles of the power 
or load switch; and 
(3) in the switch chamber, the electrical connections between the upper or 
lower terminals of the power or load switch and the bushing-type current 
pins is effected in a straight line or at an angle, in mutually parallel 
planes for the respective phases. 
The arrangement of the lines according to the invention results in a number 
of advantages compared to the prior art switching system and similar 
products on the market, the most important ones of these advantages being 
the following. 
(a) Due to the straight-line, uncrossed arrangement of the lines, the depth 
of the bus bar chamber can be minimized. 
(b) Due to the diagonal arrangement, the distance between the current paths 
of the disconnect or three-way switches is clearly greater, with a given 
bus bar division than in the prior art switching system. This noticeably 
reduces the danger of electrical sparkover and thus the introduction of a 
malfunction into the bus bar chamber, even if it is considered that parts 
of the current paths may have a configuration at individual locations 
which is unfavorable from a high voltage point of view. 
(c) Due to the arrangement of the electrical connections without crossovers 
within the protected chambers, it is possible to apply grounded partitions 
to separate the lines by phase. This considerably increases the 
availability of the switching system since in the case of malfunction no 
high current phase sparkovers but only earth-fault arcs are able to occur 
similarly to a single-phase encapsulation. Moreover, the phase partitions 
according to the invention are connected with the protective wall in an 
intersecting manner and thus reinforce the protective wall to a special 
degree. Thus no deformations and thus no untightness will occur in the 
case of malfunction at the locations where the insulated passages are 
screwed in. 
(d) The idea of the invention can also be utilized if the prior art block 
or cube-shaped protected chambers of the basic switching system are 
combined into a one-piece housing, in which case "nesting" of the 
protected chambers and thus further reduction of the enclosed volume of 
the switching system can be realized effortlessly. Moreover, there will 
then be only a few locations that have to be sealed and thus the leakage 
rate will be lower. 
(e) Another advantageous feature of the invention is the use of separate 
housings for the bus bar chamber and the switch chamber so that, in the 
case of a malfunction in the switch chamber, the latter can be removed as 
a whole without it being necessary to interrupt operation in one of the 
bus bar systems.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In FIGS. 1A and 1B, bus bar chamber 11 of the prior art switching system 
has a block shape and contains superposed bus bars 1, and respective leads 
2 connecting the respective bus bars to the counter contacts of respective 
bus bar switches in the form of three-way switches 3 whose axes of 
rotation 4 are attached phase by phase to passages or pass-throughs 13 
installed in a gas-tight manner in a protective wall 12. Respective 
connecting lines 5 connect each one of passages 13 with a respective pole 
6 of the power switch 9 disposed in switch chamber 14. The height of bus 
bar chamber 11 is determined by the diameter d of the bus bars 1, the 
distances a between adjacent bus bars 1 and the distances b between the 
upper and lower walls of the chamber 1 and the upper and lower bus bars 1, 
respectively, while the depth of chamber 11 is determined by distance c 
from the bus bars 1 to the side wall, the diameter d of the bus bar, the 
depth e of the bent lead 2 which intersects the middle bus bar and the 
length f of the moveable switching member 8 of three-way switch 3. The 
phases of the three-way switch have axes of rotation 4 which are aligned 
with one another, and their pivot planes, which are parallel to one 
another, are spaced from one another at the same distance p as the 
separation of the centers of the poles 6 of the high voltage switch in the 
form of power switch 9. Due to the length and configuration of leads 2, 
the countercontacts (fixed contacts) 7 must be fastened to isolators (not 
shown). 
FIGS. 2A and 2B show, for the switching system according to the invention, 
that the height of bus bar chamber 21 is determined by the same parameters 
as in the prior art switching system according to FIGS. 1a and 1b. 
However, the lines extend in straight lines in the individual phases, from 
bus bars 1 to passages 13 by way of the three-way switches 3, in mutually 
parallel planes, so that only the dimensions c, d and f are determinative 
for the depth. It can also be seen in FIG. 2B that passages 13 are aligned 
phase by phase with poles 6 of the power switch and thus are in a diagonal 
line along protective wall 12 in a staggered manner (FIG. 2C). In this 
way, it is possible to realize the shortest possible lines in each phase 
between bus bar 1 and power switch pole 6 by way of a three-way switch 3, 
a bushing-type current pin 51 disposed in passage 13 and a connecting line 
5, with countercontact (fixed contact) 7 for the movable switching element 
8 of three-way switch 3 being attached directly at bus bar 1 without any 
additional support from an isolator. The straight line arrangement of the 
conductors as proposed by the present invention also substantially avoids, 
in the case of a short circuit, the generation of electrodynamic forces 
which could act on the line sections. In each phase, the axis of rotation 
4 intersects, at a right angle, the plane defined by bus bar 1 and 
three-way switch 3 in which thus also takes place the pivoting movement of 
the switching member 8 of three-way switch 3 during switch-off and 
grounding. The width of bus bar chamber 21 can be minimized in that, 
according to FIG. 2B, the three-way switches 3 for the two outer phases 
are pivoted in opposite directions toward the interior of the switching 
system, with the pivoting direction of the center phase being selectable 
as desired. As is clear from FIGs. 2A-4 the housing (enclosure) 20 has 
chambers 14 and 21 which are cube or block shaped and planar covers 17, 
the chambers being separated by protective walls 12. 
Referring to FIG. 3A and 3B, the proposed arrangement of the conductors in 
bus bar chamber 21 can also be employed in a switching system in which 
this chamber lies above switch chamber 14 and is rotated by 90. with 
respect to the switch chamber. The connecting lines 5 between bushing-type 
current pins 51 and switch poles 6 in switch chamber 14 and the associated 
partial volume 14a extend with different bends (FIG. 3A) but in mutually 
parallel planes (FIG. 3B). Thus, the diagonal arrangement of the three 
passages 13 in protective wall 12 remains in effect, as in FIG. 2C. 
In the description above, disconnect switches and separate devices can also 
be employed instead of the three-way switches to operationally ground the 
branches. 
The structural configuration of a single bus bar system according to the 
line scheme of FIGS. 2A, 2B and 2C can be seen in FIG. 4. A housing 20 
includes a block-shaped bus bar chamber 21 and a switch chamber 14 and has 
a one piece construction. Protective wall 12 is provided with passages 13 
in a diagonally offset manner, with the three-way switches 3 being mounted 
in a rotatable manner on the pins 51 at these passages 13. Bus bars 1 are 
arranged in straight lines above one another and are mounted in passages 
(not shown). A gas-tightly attached cover 23 seals the installation 
opening of bus bar chamber 21. 
The power switch 9 is composed of three poles 6 (only one of which is seen 
in the figure) and a drive 24 whose basic frame 25 seals the installation 
opening of switch chamber 14 in a gas-tight manner with sealing strips. 
Drive 24 also includes, outside of the gas filled chamber, an energy store 
for switch-on and switch-off and the usual control and signalling members. 
The driving movement is transferred by way of gas-tightly mounted cranks 
26 and an insulated switching rod 34 to the movable switch contacts of 
poles 6. In order to facilitate maintenance of power or load switch 9 and 
its movable parts, without requiring larger installation openings at 
housing 20, the electrical connections to the upper (bar or bus 
connection) and lower (power) terminals 59 and 59' of the power switch 9 
are effected by way of simple plug-in contacts 27. 
Plug-in the respective plug-in contacts 27 disposed at the two (upper and 
lower) regions of the terminals 59 are preferably at the same heights for 
all three poles 6. Connecting lines 15a, 15b, 15c to bushing-type current 
pins 51 thus have different lengths and are arranged phase by phase in the 
same planes as the respective poles 6 of the power switch. The distance 
between the voltage carrying phases is nowhere reduced by bends or 
intersecting conductors. Since the bushing-type current pins 51 and poles 
6 of power switch 9 are very stable supports, additional supports for the 
connecting lines, particularly by means of isolators and the like, can be 
substantially avoided. 
Housing 20 changes in its lower connection region to single-phase 
encapsulated cylindrical connecting chambers 28 (see FIG. 5), with one 
cable being connectable in each by way of a high voltage plug 29 and a 
cable terminal or socket 19. Connecting chambers 28 are arranged in the 
form of a triangle and may be equipped, on their exteriors, with the 
secondary windings of transformers 30 as known from prior art structures. 
Moreover, further cable terminals or plug-in sockets 31 for the connection 
of voltage transformers or for the application of normally grounded 
connections or the like, may be provided for each phase in the lower 
region of housing 20. As shown the sockets 31 extend preferably in a 
horizontal (rear to front) direction and are connected to respective short 
lines 18 adjacent the respective lower connection terminals 59 of the 
switch 9. The cable terminals or sockets 19 are connected phase by phase 
with the lower plug-in contacts 27 by means of the short lines 18. Instead 
of the triangular arrangement of FIG. 5, the power cable terminals 19 may 
also be arranged by phase in a diagonally staggered arrangement with 
respect to the front of the system. 
According to a further feature of the invention as shown in FIGS. 4 and 5, 
grounded partitions 22 and 32, respectively, separate bus bar chamber 21 
as well as switch chamber 14 over their entire height and depth into three 
single-phase, mutually not gas-tight chambers. These chambers are not 
sealed with respect to each other. Partitions 22 and 32 form a right angle 
with one another and abut on both sides of protective wall 12, being 
firmly connected therewith, for example by welding. Protective wall 12 is 
thus optimally reinforced which has an advantageous effect, primarily in 
the case of arc interference in one of chambers 21 and 14, since passages 
13 which are inserted in a sealed manner cannot become untight due to 
dents in protective wall 12. In this way, the unaffected protected 
chamber, e.g. bus bar chamber 21, remains operational without limitations. 
According to a further feature of the invention, primarily slit-shaped 
connecting openings 35 are provided, for example, in partitions 22 and 32, 
respectively, opposite cover 23, and basic frame 25 for drive 24, where 
during operation of the system there are relatively low electric field 
intensities. These openings provide gaseous communication between the 
subdivisions and therefore in the case of pressure development due to an 
internal arc, these openings enable a pressure equalization to take place 
within protected chambers 14 or 21 and thus partial overloading of one 
partial chamber is prevented. Additionally, partitions 22 and 32 are 
connected with adjacent covers 17 which are firmly attached and thus 
reinforce them as well. 
A switching system according to FIG. 4 rests on a base 33 whose height is 
dependent upon the accessibility of the high voltage plugs 29 during 
installation. 
FIG. 6 shows a double bus bar system based on a single bus bar system as 
shown in FIG. 4. The second bus bar chamber 41 here has its conductors or 
liner arranged as shown in FIG. 3 and is accommodated in a housing 40 in 
which part 14a of an enlarged switch chamber is also disposed and includes 
connecting lines 42a, 42b, 42c from bushing-type current pins 51 to 
plug-in contacts 27 at the upper side of the poles 6 of power switch 9. 
As shown in FIGS. 4 and 6, the internal configurations of the two bus bar 
chambers 21 and 41 are completely identical. This also applies for the 
configuration and drive of the three-way switches which will be described 
below. 
For each phase, the three-way switch 3 is pivotable either in the 
respective phase plane defined by the axis of the corresponding bus bar 1, 
the corresponding bushing-type current pin 51 and the current path through 
the switch 3 in its closed position or in a plane parallel to and 
separated by a small distance from, the respective phase plane. According 
to FIGS. 7A and 7B, a three-way switch 3 is composed of a support 50 made 
of sheet metal whose axis of rotation 4 is mounted in a fork of 
bushing-type current pin 51. Symmetrical current carrying contact bridges 
52, in the present case two on each side, are attached to support 50 by 
way of contact springs 53 in such a manner that, in the switched-on state, 
they connect pin 51 with countercontact 7 fastened to bus bar 1. Support 
50 is provided with an eye 55 at which engages a drive rod 56 for each 
switch. Eye 55 is arranged in such a manner that the switch, for example, 
of the outer phase on the left, as shown in FIG. 8, can be moved by means 
of drive rod 56 from the operating position I shown in FIG. 7A to the 
disconnect position II and the grounded position III. 
In the grounded position III, contact bridges 52 contact ground contact 54 
which is in conductive communication with the grounded protective wall 12, 
for example by way of a weld. 
FIG. 7A also shows the gas-tight installation of passage 13 in protective 
wall 12. Consequently, passage 13 is inserted together with the already 
attached three-way switch through the installation opening of bus bar 
chamber 21 or 41 (FIG. 4 or FIG. 6) and is tightened against protective 
wall 12 by means of clamping rings 57 and 58 and screws. The seal is here 
provided by gaskets 43 and 44. 
In the selected embodiment shown in FIG. 8, the three-way switches for 
phases L1 and L2 open clockwise and the switch for phase L3 opens 
counterclockwise (see FIGS. 2b and 3b). Moreover, for kinematic reasons, 
the direction of the switch-on contact bridges 52 slightly deviates from 
the elongate, straight path, as mentioned in the present specification in 
connection with FIGS. 2a and 2b, which, however, does not narrow the 
advantages of the inventive idea. 
FIGS. 8 and 9 show the drive for the three-way switches of a bus bar 
chamber 21 or 41. As already indicated in connection with FIG. 4, a drive 
shaft 71, coming from a drive outside the switching system encapsulation, 
enters into bus bar chamber 21 or 41 through a bearing location 72 
provided with sealing means and penetrates partitions 22 between bus bars 
1 for phases L.sub.1 and L.sub.2 and for phases L.sub.2 and L.sub.3, 
leaving a narrow gap. The position of these phases is also shown in FIG. 
4, for example. In order to transfer the switching movement to phases 
L.sub.1 and L.sub.2, a respective crank 73 is provided on drive shaft 71 
for each of these phases, with drive rods 56a and 56b establishing a 
connection with the respective three-way switches (not shown in FIGS. 8 
and 9; see FIGS. 7A-7B). In the partition 22 between phases L2 and L3, 
drive shaft 71 is guided in a bearing 74 and transfers its motion into 
rotation of a second rotatably mounted shaft 77 in an opposite direction 
through a four-bar mechanism installed on that partition 22. 
In particular, the shaft 71 is terminated by a crank 75 which, by way of 
rods 76, moves a second shaft 77, and from there by way of a crosswise 
arranged drive rod 56c, crank 75 moves the three-way switch belonging to 
phase L.sub.3 which is switched in the opposite sense of rotation. The 
rods 76 are covered against the voltage carrying components by a shield 78 
mounted on the partition 22. 
FIG. 9 also shows the installation opening 35 for bus bar chamber 21 and 
its cover 23 as well as the connecting opening 35 between the partial 
chambers defined by partitions 22. Additionally, FIG. 9 shows the 
protective wall 12, bus bars 1 and their passages 82 as well as the 
gas-tight screw connection 83 between two adjacent switching systems. This 
figure also shows how the problem of fastening the bus bars is solved for 
an end field. However, these details are not of significance for the 
present invention and will therefore not be discussed further. 
FIG. 10A shows the switching system according to the invention with a 
connecting region disposed above the bus bar chamber, as used in stations 
not employing cable channels. Bus bar chamber 91 and switch chamber 92 
here have the same significant features as shown in FIG. 4. Switch chamber 
92 is partitioned in such a manner that cable terminal 19 and at least one 
high voltage plug 29 per phase are provided behind power switch 9 and 
above bus bar chamber 91. Housing 93 may here have a flush rear wall 94, 
as shown in FIG. 10A with the terminals or sockets 19 for the plugs 29 
inserted horizontally in a rear to front direction connect, or, as shown 
in FIG. 10B, a part 95 which projects beyond bus bar chamber 91 and into 
which the terminals 19 for the plugs 29 are inserted vertically (in the 
direction of alignment of the bus bars 1) from the bottom. In the upper 
part of switch chamber 92, vertically extending plug-in sockets 31 are 
provided for the connection of voltage transformers and the like. In this 
embodiment, partitions 96 in switch chamber 92 pass around protective wall 
12 on two sides. 
Switching systems having the cable terminals at the top can also be 
modified in an advantageous manner to serve as double bus bar systems. The 
arrangement of FIG. 11 in housing 403 here represents a possible 
embodiment in which the essential features of the invention are employed 
in switch chamber 92 as well as in the two bus bar chambers 91 and 98, the 
partial volume 92a containing the connecting line conductors 42a, 42b, and 
42c. The same reference numerals apply as used in FIG. 10A. 
The basic configuration of the switching system according to the invention 
can also be configured, as shown in FIGS. 12A and 12B, to have a two-part 
housing 60 and 60a. Housing part 60 here accommodates bus bar chamber 61. 
This chamber is defined by protective wall 12 and its passages 13. Switch 
chamber 62 is provided in housing part 60a which is open with respect to 
protective wall 12. The two housing parts 60 and 60a are connected 
together, by way of a fastening device 63 (not shown in detail) in a 
gas-tight but releasable manner. This embodiment has the advantage that, 
if there is a malfunction in any part of switch chamber 62, the latter can 
be disassembled completely, once the insulating gas has been discharged, 
and can be exchanged for a new one. The supply of energy to the remainder 
of the switching systems need then not be interrupted since bus bar 
chamber 61, with three-way switches 3 grounded, remains ready for 
operation. 
FIGS. 12A and 12B, respectively, also show partitions 22 and 32 
schematically. According to the concept of this embodiment of the system, 
the two partitions 22 are firmly connected with the protective wall 12, 
e.g. welded to it, while partitions 32 lie against the protective wall, 
releasable at any time. 
FIG. 13 shows a triple bus bar system. Based on the configuration according 
to FIG. 4 or FIGS. 12A, 12B, two symmetrically arranged bus bar chambers 
99a and 99b are accommodated in a housing 80. Each one of the bus bar 
chambers corresponds in all details to bus bar chamber 21 in FIG. 4 and to 
bus bar chamber 41 in FIG. 6, respectively. The center part of housing 80 
accommodates a partial volume 14a of switch chamber 14 including 
connecting lines 84 which establish a connection between bushing-type 
current pins 51 and plug-in contacts 27 of power or load switch 9. In 
operation, a cover 81 closes the installation opening of the center part 
in a gas-tight manner. Housing 80 is connected with housing 20 or with the 
two-part housing 60/60a of the basic embodiment likewise in a gas-tight 
manner. 
The power or load switches 9 may be vacuum switches. It is also conceivable 
in each embodiment to use the insulating gas, such as SF6, provided in the 
switch chamber (14, 62 or 92) as the quenching agent for the power and 
load switches 9. 
The present disclosure relates to the subject matter disclosed in Federal 
Republic of Germany Patent Application No. P 37 15 053.7, filed May 6, 
1987, the entire specification of which is incorporated herein by 
reference. 
It will be understood that the above description of the present invention 
is susceptible to various modifications, changes and adaptations, and the 
same are intended to be comprehended within the meaning and range of 
equivalents of the appended claims.