US2857557A

US2857557A - High voltage substation

Info

Publication number: US2857557A
Application number: US414813A
Authority: US
Inventors: Imhof Alfred
Original assignee: Moser Glaser and Co AG
Current assignee: Moser Glaser and Co AG
Priority date: 1953-03-06
Filing date: 1954-03-08
Publication date: 1958-10-21
Anticipated expiration: 1975-10-21
Also published as: DE1027759B

Description

y Oct. 21, 1958 A vlMHQF 2,857,557

HIGH VOLTAGE SUBSTATION .Filed March 8', 1954 4 Sheets-Sheet 1 A .9 Z 49 M; F75. 5.

4 INVENTOIL Ha/@50. IMA/ox:

A. lMHOF HIGH VOLTAGE SUBSTATION l Oct. 21, 1958 4 Sheets-Sheet 2 Filed March 8; 1954 INVENTOR. 44 FP50 .ZM/fop :www

Oct. 21, 1958 A. lMHoF HIGH VOLTAGE suBsTATIoN 4 Sheets-Sheet 4 Filed March, 1954 v /ZO 7a IN V EN TOR.

402250 221f1f/ofc' BY v States Patent HIGH voLrAoa sUBsrArroN Alfred Imhof, Zurich, Switzerland, assignor to Moser- Glaser & Co., A. G., Muttenz, near Basel, Switzerland Application March 8, 1954, Serial No. 414,813 Claims priority, application Switzerland March 6, 1953 39 Claims. (Cl. 317-9) The invention relates to electric high voltage apparatus, and more particularly to a high voltage apparatus for connecting lines or bus bars with each other.

It is an object of the present invention to provide a high voltage apparatus of the kind described which forms a completely metal enclosed substation.

It is another object of the present invention to provide a high voltage apparatus capable of withstanding voltages of 60 kilovolts or more.

Other objects and advantages of the present invention will become apparent from the following detailed description thereof when read in connection with the accompanying drawings forming part of this specification and illustrating, by way of example, some embodiments of the present invention. In the drawings:

Fig. l is a sectional view of an embodiment of the coupling means according to the invention;

Figs. 2 to 6 are, respectively, sectional views of other embodiments of the coupling means according to the invention;

Figs. 7, 7a, and 8, are respectively, sections of two.

further embodiments of the present invention;

Fig. 9 is a wiring diagram of certain parts shown in Figs. 7, 7a, and 8;

Fig. 10 is a sectional view of still another embodiment of the invention; and

Figs. ll and l2, are, respectively, sectional views of two more embodiments of the invention.

Referring now to the drawings, it will be seen that in a substation according to the invention syntheticA resins are provided as insulating layers between the high voltage parts and the grounded metal enclosure. VFluid insulating materials such as oil or compressed air are used only in very limited quantities in coupling joints between solid parts and in ducts in which component parts of the apparatus are moving. Each phase 'may be enclosed separately, or all phases may be enclosed together provided the voltage is not too high.

The above mentioned synthetic-resin must be of the type which is liquid during the casting process and hardens without giving off volatile components. Resins that harden at room temperature, as well as those that harden at elevated temperatures may be used. The hardening maybe effected by means of either polymerization or polyaddition. Suitable resins are, for instance, epoxy resins such as those sold in commerce under the trade name Araldite, which can be cast in liquid form .at 130 C. and are set, for instance, at about 120 C.

A fundamental component of a high voltage substation according to the invention is the electrical coupling between the current carrying bus bars. Two diierent ern` bodiments of such a coupling are shown in Figs. 1 and 2 Where a bus bar carrying high voltage includes a part 1 and a part 1a connected with each other by a contact tongue 5. The partk 1 is embedded in an insulatorZ consisting of a synthetic resin of the kind referred to above, and part 1a is embedded in a similar insulator 3 consisting also of synthetic resin. Metal coverings 4 and 2,857,557 Patented Oct. 2l, 1958 4a are arranged on the outside of the

insulators

2 and 3, which are separated by a conical joint 6 (Fig. l) or a joint 6 (Fig. 2) having a V-shaped cross-section which is lled with a uid or uidized insulating material 'such as a heavy oil, a chlorinated biphenyl, a chlorinated phenylidan, a peruoroether such as perfluorohexylether (C6F13)2O, or perfluoro-CB cyclic ether c-CaFlGO, a uoro-t-amine such as triperfluoropropylamine (C3F7)3N, a half liquid polyvinylchloride, a gaseous chlorinated methane of high dielectric strength, or a compressed gas. Fluorine compounds are in particular suitable as a dielectric for the joint owing to their high dielectric strength, stability, heat resistance, noninammability, and high Iboiling point.

Since only small quantities of the dielectric are needed in the narrow joints, even expensive substances may readily be used.

A reservoir 7 containing the fluid insulating material is connected through a pipe 102 having an orice 103 arranged in the ange :1 with a circular chamber 104 forming the outer end of the joint 6. Instead of providing separate reservoirs such as 7 for each joint, a central reservoir or tank may be used, which suppliesv all the joints with the fluid insulating material. By the use of pressure, a complete lling of all joints with the iluid insulating material can be insured, which provides for increased electric strength.

In such a joint coupling, only readily controllable axial electrical forces are set up. Tests of such joints have shown that with smooth joint walls and transformer oil as the insulating material a creepage gradient of 25 kv./cm. (R. M. S.) and more is attained.

In the embodiment of the invention shown in Fig. 3 the joint 6 is curved so that the voltage stress along the joint surface is substantially constant. Y

In the embodiment shown in Fig. 4 of the drawings, the joint 6a is formed by interengaging cam surfaces which in cross-section form a zigzag line 6a the slopes of which vary, e. g. decrease from the conductor 1 to the

metal coverings

4, 4a. In this construction, the axial length of the joint is shortened in comparison to the joint 6" shown in Fig. 3.

Referring now to Fig. 5 of the drawings, the metal coverings have conical parts such as 106 and 106a connected along the

base flanges

107, 107a thereof with one another by screw bolts such as 108. The conical parts 106 and 106a accommodate, respectively, the conical base portions 2a and 3a of the

insulators

2 and 3, which base portions each from a plurality of ridges and 10551l and grooves 9 and 9a, respectively. The ridges 10S of the insulator 2a are arranged opposite to the ridges 105a of the insulator 3a so as to increase the creeping path. If the grooves 9 and 9a have a depth exceeding a predetermined minimum value the breakdown of the dielectric will bea puncture of the fluid insulating material lling the joint 6b and the grooves 9, 9a instead of a ashover along the creepage surfaces (e. g. Fig. 5).

However, if desired, the ridges 105 and 105a can be arranged oppositely to the grooves 9 and 9a, respectively, so as to extend the length of the electric creeping path.

The joint shown in Fig. 5 allows of a lateral removal of. the coupling Ibecause no parts of the solid dielectric of the coupling are interlocked with the solid dielectric of the apparatus. The contact is shown here by way of example as a pressure contact 8.

Tests have shown that with respect tothe electric strength of the joints-certain solid dielectrics used as llers, such as polyethylene, behave, when under pressure, similarly to fluid dielectrics proper. It is, therefore, to be understood that the term Huid dielectrics embraces also suchgsolid dielectrics which have owing properties, particularly when they have a liquid surface film or a surface lm of pasty consistency. The term equally applies to porous materials, for example paper, which are impregnated with a freely owing dielectric, such as oil.

Referring now to Fig. 6 of the drawings, a coupling ac.- cording to the present invention is shown which makes it possible to actuate internal parts which are at a high potential by imparting thereto rotary or translatory motion by means of screw threads, worm gears Or ,the like. At the outside, the coupling must be provided in this case with armatures having gliding surface yFor instance, the embodiment shown in Fig. 6 includes a revolvable insulator 11 arranged between the

insulators

2 and 3 separated therefrom by joints 6c and 6d, respectively. The insulator 11 may be rotated by a ,rotating shaft 116 carrying a worm 14 engaging a worm wheel 13 arranged at the circumference of a flange 113 of a sleeve 117 having a U-shaped cross-section and being connected with the insulator 11. The

outer coverings

4 and 4a of the

insulators

2 and 3 have flanges 1 19 connected by iluid-tight joints 15 with the anges 120 of the sleeve 117- The inner part 12 of the insulator 11 is threaded and engages a threaded part 121 of a rod 10 tov which a high potential is imparted.

The insulator 11 is coupled with the rod 10 by means of the threaded part 121 engaging the part 12 of the insulator 11 so as to impart to the rod 10 translatory motion to and fro in the axial direction of the rod. If desired, the gear connecting the insulator 11 with the rod 10 may be designed so as to impart a rotatory motion to the rod 10 about the axis thereof.

In sections having discontinuities in the bus bars, as for example in circuit breakers and disconnecting portions, the bus bar ends must be designed in a special manner to avoid an excessive increase of the electric field strength in thel surrounding insulation. The invention provides two solutions to this problem. One solution consists in designing .the busl bar ends within Spheres or sphere-like electrodes4 such as those shown for example in Fig. l0. TheV other solution consists in the embedding of stress controlling condensers as shown in Fig. 7, which illustrates a complete apparatus according to the present invention, the wiring diagram of which is shown in Fig. 9 of the drawings.

The embodiment shown in Figs. 7 and 7a serves for connecting a high voltage cable 70S with a bus bar 771 and includes a cable section 701 having a termination 708', a coupling member 702 coupling the cable section 701 with a section 703 being formed as a disconnecting switch more fully to be described hereinafter, a section 704 including a potential transformer and a current transformer also more fully described hereinafter. The section 704 couples the section 703 with a section 705 including a circuit breaker, an auxiliary coupling member 706 coupling the circuit breaker section 705 with a section 703' similark to section 703. and being formed as a disconnecting switch, and a section 797 connecting the section 703 with the bus bar '771.

Section 703 being formed as a disconnecting switch comprises two spherical or almost

spherical electrodes

709 and 710 embedded into the

solid dielectric

721, or 721a, 723 and forming, respectively, the ends offhollow

cylindrical switch members

711 and 712 which may be either electrically connected or disconnected by a metal contact rod 713 arranged for longitudinalmotion in a channel. 714 extending from the termination 7,08' through the hollow cylindrical metal member 711 to the hollow electrode 710. The channel 714 is filled with a fluid dielectric such as air or heavy oil. The rod 713 ,can be axially displaced, for example electromagnetically, under the action of a spring (not shown) or by a servomotor 715 the shaft 715 of which is engagedrby a rack 713s formed on the rod 713. The 'servo-motor is connected to the secondary 717 of an insulating transformer having an iron core 716 and a primary winding 718, so

`that the servo-motor 715 is supplied with the high secl ondary voltage of the insulating transformer 7 16,7178

. grounding rod (not shown) may be pushed as far as the axis of the disconnecting switch through a channel 719 arranged at right angles to the axis so that a creepage path leads from the disconnecting switch to ground.

Alternatively, the disconnecting switch may comprise two rods (not shown) making contacts with each other in lthe middle of the channel 714 and moving in opposite direction when the disconnecting switch is to be opened. In such a disconnecting switch, the one half is identical with section 703 of Fig. 7, the other half is the mirror image of said first half. In Vthis way, the disconnecting switch possesses two spherical electrodes 709, each pro-v vided with a s ervomotor 715 for controlling the contact rods 7.13. Each servomotor is supplied from an insulating transformer 716-718 as set forth hereinabove.

Section 704 includes a bus bar 738 embedded in an insulator 737 consisting of synthetic resin and enclosed by a metal covering 740b. connected, respectively, withl the metal coverings 703b and 705b of switches 703 and 70,5 by screws such as 7.04. Embedded in the insulator' 737 are the Vprimary winding 739 and the secondary winding 7,40 of a potential transformer having an iron core 741 being partly outside the metal covering 704b and the insulator 737. Also

iron cores

742 and 743 of current transformers are arranged so as to surround the bus bar 738 forming the primary winding thereof, whereas the secondary windings 74251 and 743a of the current transformers are embedded in the insulator 737.

Section 705'is a circuit breaker section comprising two contact rods '727 and 723 arranged opposite to each other in a 4channel 724 filled with compressed air, and connected, respectively, to the bus bar 733 and a hollow electrode 726 formed as body of revolution about an axisv coinciding with the common axis line of the

rods

727 and 728, yof which rod 727 is stationary whereas the rod 728 is arranged for translatory motion and actuated by a compression spring 729 acting on a piston 730 so as to close the circuit breaker including the

contact rods

727 and 728. The circuit breaker opens its contact when air is applied to the piston 730 overcoming the force of the' spring 729; on displacement, said piston opens a connecting channel to the hollow electrode 726 and allows thc compressed air to enter said electrode. The arc between the contact rods 727 and 72S is confined to a narrow section 737 of the channel 72.4. If desired, the circuit breaker may be equipped with multiple contacts (not shown) and a plurality of arc coniining sections places in series to one another.

Compressed air is'supplied to the circuit breaker over a channel 732 traversing the insulating wall 705C andy provided with valves 732a and 732b at the ends thereof., to a chamber 725 surrounding part of the stationary rod 727 and communicating with the channel 724. The thickness of the insulating well 705e depends on the voltage against ground of the stationary rod 727 so as to obtain a suitable flashover voltage; The valves 7320 and 73211 are designed as check valves ensuring that the` chamber 725V and the channel 732 are filled ,by compressed air. Y

The hot gases emitted by the opening arc between the rods 727V and 728 escape at a high velocity into the hol low electrode 726 having a strongmetal wall in order to take up rapidly a considerable portion of the heat developed by,A the hot Agases which escape slowly to the atmosphere through the channel 734 provided at its ends with checlcvalves Y733; The valve arrangedat the enA tranc'eof'the channel 734 is designed so as to open 'slowly Aunder the influence of the increased pressure prevailing within the air chamber formed by the hollow electrode 726, in which the lrot air can be cooled. This isnecessary since hot air has a low dielectric strength so that some damage might be done to the insulating wall. Circuit breakers subject to very high voltages require stress controlling condensers such as 735 connected in series and embedded into the insulating material so as to surround the air channels 734.

The closing of the circuit breaker is accomplished by suitable devices (not shown) which are well known in the art.

The hollow electrode 726 is continued by another hollow electrode 736a being rigidly and electrically connected with a metal rod 760 arranged for making contact with the ycontact rod 713 forming part of the section 703', which is a disconnecting switch similar to the disconnecting switch formed by section 703 so that no detailed description thereof is deemed necessary.

As will be seen from Figs. 7 and 7a, all sections 702-707 comprise, apart from the current-carrying membersv thereof, insulator 70211 and metal coverings 702b which are the analogs of the

insulators

2, 3 and the

metal coverings

4, 4a described hereinbefore. The insulators consist of synthetic resin and some of the insulators, for instance those arranged in the section 703, are provided with a channel 719 for allowing the entry of gases or liquids or of solid members such as rods or cables to be applied between ground and the high volta'ge current carrying rod 713. a continuous insulating surface from the grounded metal coverings to the inner parts such as 713 which are at high voltage. r

The inner parts of the various sections 703-703 may be assembled, taken apart, or checked as follows: The two spherical orgnearly

spherical bodies

709 and 710 of section 703 are removable to allow replacement of contacts (not shown) or access lto the servo-motor 715 arranged within the body 709. In order to accomplish this, a cylindrical body 721 consisting of synthetic resin is separated from the body 721a by a joint 720 filled completely with a fluid insulating material, and the bodiesV 721 and 72la are detachably secured together. The same applies to the cylindrical body 723 which is separated from the body 721a by a joint 722.

An alternate assembling and disassembling procedure will be explained with reference to sections 705 and 706. In order to render accessible the inner parts'of section 705, the coupling member or section 706 is removed so that the opening 736 becomes accessible, thus giving access to the inner parts of section 705 more fully described hereinbefore. v

As set forth hereinabove, the operation of circuit breaker contacts or disconnecting contacts and of other partsconnected to high voltage may easily be secured by the revolvable joints mentioned hereinbefore, or by means of embedded electromagnets or servo-motors such as 715, for which the voltage may be supplied by a low voltage network (not shown) by means of servo-transformers such as 716-718 which are embedded in the insulators 721a.

Most of the apparatus belonging to a section such as disconnecting switches, transfer switches, current transformers, potential transformers, circuit breakers, etc., are designed in such a manner that they may be mounted directly in line with the bus bar which is arranged so as to be approximately in line with the longitudinal axis of the apparatus. Embodiments of such a design have been explainedV hereinabove. l

In order to keep the distances of the phases from one another as short as possible, all parts protruding at right angles touthe axis of the system such as the part 732 should be arranged so that they protrude in one and the same .direction which shouldr be perpendicular to the plane connecting the bus bars of neighboring phases.

These channels provide Referring now to Fig. 8 of the drawings, a composite bus bar is shown connecting a cable 808 with a bus bar 871, said part being the analogue of the cable 708 and the bus bar 771 shown in Fig. 7, and including

sections

802, 803, 804, 805, 806, 803 and 807 being the analogue, respectively, of

sections

702, 703, 704, 705, 706, 703 and 707 of Fig. 7 so that a detailed description of these sections is deemed unnecessary. However, whereas in the arrangement shown in Fig. 7 all the sections are aligned with one another, in the arrangement shown in Fig. 8 the sections'802-804 are aligned and the same applies to sections S05- 807 in the reverse direction. Two,

sections

812 and 818 are interrelated in series between sections 804and 805. One of these sections, viz. section 818 comprises a bent metal cover 820 connected to thev grounded covers 821 and 822 of

sections

812 and 805, respectively, an insulating body 823, and a bus bar segment 824 being electrically connected with the bus bar element 838 forming part of section 804 and the rod 827 forming part of the circuit breaker section 805. The

bus bar segment 824 is curved so as to align smoothlywith the bus bar element 838 and the rod 827.

In Fig. l0 a so-called transfer switch is shown byv which an incoming line (not shown) is connected to one of two.conductors (not shown). The incoming line is held by a clamp 1021 arranged in the upper part of a spherical electrode 1003 and connected by a flexible connection (not shown) to a contact rod 1006 provided with a rack 1006a being in engagement with a worm 1008a driven by a servo-motor 1008 fed by the secondary 1011 of a transformer having an iron core 1010 and a primary winding 1012, so that the contact rod 1006 can be displaced in axial direction within the channel 1007 provided in the insulating body 1001. The channel 1007 ends to the left and to the right, respectively,

terial as the insulating body 1001 from which they arey separated by the

joints

1024 and 1025, respectively.

The insulating body 1001 is preferably provided with channels such as 1009 and/or 1009 which are arranged symmetrically at either side of the transformer 1010- 1012 and receive grounding rods (not shown). A grounded metal covering 1030 is provided at the outside of the transfer switch.

In operation, the contact rod 1006 is either kept in its left-most position as shown in Fig. 10 where it makes contact with the metal sleeve 1005, or in the right-most position (not shown) where it makes contact with the sleeve 1004, so that the incoming line (not shown) connected to the contact rod 1006 is alternately connected to the conductors (not shown) which are connected, respectively, with the

metal sleeves

1005 and 1004.

In the embodiment shown in Fig. ll of the drawings, a disconnecting switch is shown which comprises a stationary portion 1100 and a movable portion 1101. y The stationary portion includes two

metal rods

1111 and 1112 aligned with one another and ending in cup-shaped

contacts

1106 and 1116, respectively, arranged in spaced relationship parallel to each other. The

rods

1111 and 1112 andthe cup-shaped

contacts

1106 and 1116 are embedded in an insulating body 1104 consisting of a synthetic resin of the type described hereinbefore and having two cup-shaped

cavities

1120 and 1121 arranged parallel gaging thel correspondingly shaped end portions (not shown) of other circuit elements (not shown).

vThe movable portion 1101 includes a U-shaped metal` d. 1.1.0.3, theends of which are adapted to make contact with the cup-shaped

contacts

1106 and 1116 of thel stationary portion 1,100. The U-shaped rod 1103 is embedded except at its ends ina U-shaped insulating body 1106 having conical end portions such as 1130 iittirig into the cavities 1120 and` 1121. A metal covering 1128 encloses the main portion of the U-shaped insulating body 1105 so as, to make contac twhen the disconnecting switch is, closed, with the grounded metal covering 1123 of the stationary portion 1100 and to form a continuation thereof.

Fig. ll shows the disconnecting switch with the portions 1100 and 1101 thereof in closing position for connecting the

metal rods

1111 and 1112 through the U- shaped metal rod 1103, For opening the disconnecting switch, the movable portion 1101'` is pulled out of the cup-shaped'

cavities

1120, 1121, so that the ends of the U-shaped metal. rod 1103,` are. removed from the cupshaped contacts 1 106 and 1116.k

' If it is intended to use the disconnecting switch shown` in4 Fig. 1l in. a very high voltage` circuit, the insulating stress within the insulating

bodies

1104 and 1105 should be, controlled by stress controlling condensers (not shown) analogous to the stress controlling condensers 735 shown in Fig. 7a.

Referringrnow to, Fig. 12, it will be seen that the disconnecting switch shown in this iigure is similar to that shown in Fig. 1,1 and that especially the

parts

1204, 1206, 12071207a, 1211, and 1212 thereof have the same function, respectively, as the

parts

1104, 1106, 1107, ll07a', 1111, 1112 shown in Fig. l1. However, in the embodiment shown in Fig. l2 a potential transformer and a` current transformer havey been added. The potential transformer includes an iron core 121.0 partly embedded in the,Y insulating body 1204, a primary winding 1208 and secondary windings 1209; The current transformer inciudcs'an iron core 1213,51 primary winding 1221, and asecondaryv winding 1222. lt should be noted thatthe transformers are arranged symmetrically at one and the other-'side of the middle plane A-A of the disconnecting switch.

The overvoltage or lightning arresters used in my apparatus do not, differ in principle from the conventional porcelain clad arresters but are also designed for complete metal enclosure in the manner described for the other parts of the apparatus. The arrester is tightly surrounded by an insulating wall of insulating resin of the type herein described and insulated by said wall from the metal covering. The insulating wall between the active arrester part and said earthed metal covering has a` gradually decreasing thickness from the entrance bush* ing towards the grounded end.

In another form, the arrester is of the straight line type, that is, the high voltage bus bar lies in the axis of the arrester, which is built as a solid of revolution. The

coordinating spark gaps, the voltage dependent resistorsV andv the current limiting resistors are built into coaxial cylindrical bodies.

The following description concerns the actual installation of'such a station. Three arrangements are particularly suitable:

(l) The devices and their bus couplings are placed on a horizontal track (not shown). They are equipped with wheels and can therefore be readily moved during the assembly or disassembly of an in-line station. An example of such as assembly is shown in Fig. 7, in which the rails and Wheels have been omitted. lf the bus bars run. vertically and are perpendicular to the station axis, the incoming lines need not have an offset. The individual pieces ofJ equipment are described hereinabove.

(2) The devices are mounted on one side of a vertical carrier (not shown). Each individual part can be moved along the vertical axis. For example they could be fastened to acommon screw. spindle (not shown) in order to be able tochange their position through rotation ofthe 8 spindle. If the, bus bars are horizontah the incoming lines need not have an offset.

(3) The devices. are mounted on both sides of a vertical carrier, so as to form together a U-shape. If the bus bars run horizontally, the incoming lines need not have an offset. This arrangement is shown in Fig. 8.

in all three arrangements, thei various phasesA of an nphase system can be mounted so closely to one another that the longest axial protrusionstouch each other.

Inv order tov carry out the principle of. the complete metal enclosure the incoming high voltage lines must also be metal enclosed and enter through cables which are completely metal clad'A at the station end ofthe cable terminal.

If solid dielectrics are used as lillers of the coupling joints, for instance in form. of sheets,v the surface of such. solid dielectrics can be moistened with one of the insulating liquids recitedhereinabove in order to insure a perfect contact between the synthetic resin and the` solid joint filler. For the. same purpose also salve-like substances or insulating salvescan be used, as for example a silicone paste or` solvents, which, applied to the surface of, solid dielectric, soften said. surface and make it sticky.

What I claim is:

l. A highvoltage substation comprising a plurality of metal clad, electrically connected high voltage devices mechanically coupled for ready removal and replacement. of individual devices, each of4 said devices comprising a.A form-stable insulating block of a synthetic resin, anelectric conductor firmly and substantially completely embedded in said block, and an. outer metal covering, said. insulating blocksbeing joined together plugwise to form. a susbtantially continuous insulation leaving only nar.- row gaps betweentheadjoining ,facesof said blocks, and

' said metalr coveringsv forming a, grounded metalV sheath4 enclosing the substation, said gaps being filled. with an insulating materialhaving flow properties.

2. A substation as deiined in claim l wherein said synthetic resin is an epoxy resin.

3. A substation as defined in claim l wherein said adjoining ends of said insulating blocks form conical socket joints.

4. A substation as defined in claim l wherein the adjoining endsof theinsulating blocks are curved to ensure a constant voltage stress along-v the joint surface.

5. A high voltage substation as defined in claim l, wherein the surfaces of said insulating blocks enclosing said gaps have a configuration increasing the length of the creepage path.

6. A substation as defined in claim lV comprising joints having a zig-zag' profile.

7. A substation as defined in claim l. comprising insulating bodies having straight end faces so as to allow removal of said bodies perpendicularly to the axis of the substation.

8. A substation as defined in claim 1 comprising grooved joints of the insulating bodies, the ridges of said grooves being arranged oppositeeach other.

9. A substation as defined in claim l comprising insulating bodies having opposite grooved end faces interengaging cach other to form said joints.

l0. A substation as definedin claim l wherein said joint-iil-ling insulating material has flowing properties under pressure.

1l. Asubstation as defined in claim l wherein thejointfilling insulatingv materialk is a thermoplastic substance having owing properties underV pressure.

l2. A substation as defined` in, claim l includingV means placing the joint-filling insulatingfmaterial underv pressure,

13. A substation as defined in claim 1 comprising` a'- assise? oint-filling insulating material is a porous solid impregnated with a liquid dielectric.

15. A substation as defined in claim 1 wherein said insulating bodies are composed of separate portions and the joints between said portions are filled with an in sulating material having flowing properties.

16. A substation as defined in claim l comprising an insulating transformer embedded in said continuous insulation and supplying electric energy to at least part of said high voltage devices.

17. A substation as defined in claim 1 wherein a plurality of said devices is designed as in line devices having a current conductor arranged approximately in the axis of said devices.

18. A substation as defined in claim 1 comprising a plurality of protruding parts, all said parts protruding at right angles to a plane through the axis of a neighboring substation in the same direction.

19. A substation as defined in claim 1 comprising high voltage devices having at least one hollow electrode, a duct connecting said electrodes to the outside, and a plurality of condensers embedded in said insulating bodies and surrounding said ducts, said condensers controlling the voltage gradient of said electrodes.

20. A substation as defined in claim 1 comprising a disconnecting switch forming part of said substation, said disconnecting switch having two spaced spherical terminals embedded in solid dielectric, a straight channel in the axis of said terminals, a fiuid dielectric in said channel, and a metal rod arranged for translatory motion in said channel.

21. A substation as defined in claim comprising in the symmetry plane of said spherical terminals a second channel leading perpendicularly from said straight channel to the metal enclosure, said second channel being arranged for receiving a grounding electrode in the open position and a uid dielectric in the closed position of said disconnecting switch. v

22. A substation as defined in claim l comprising a circuit breaker designed as a metal enclosed compressed air breaker, said circuit breaker having an insulation to ground consisting primarily of embedding resin, two opposite hollow substantially spherical electrodes and a compressed air channel connecting said electrodes embedded in said resin, two contact rods in said channel, one of said contact rods being stationary and the other contact rod being arranged for translatory motion, and additional channels for admitting compressed air and discharging the air contaminated by the arc between said contact rods, and means to close said additional channels so as to maintain the air under pressure.

23. A substation as defined in claim 22 comprising an air chamber for receiving the hot air from said arc and discharging said air at lower temperature through said additional channels to the outside.

24. A substation as defined in claim l comprising bus bars and transfer switches, said transfer switches having three substantially spherical terminal electrodes, tw-o of said electrodes serving as ends of the bus bars, the third of said electrodes serving as the end of the line to be switched and a plurality of contact rods forming part of said devices and being movable in translatory motion towards either one of said two electrodes by means of a servo force.

25. A substation as defined in claim 1 comprising a disconnecting switch in the form of a U-shaped plug having movable terminals and convex insulators, the axes of said insulators receiving said movable plugs.

26. A substation as defined in claim 25 wherein said disconnecting switch has a stationary part containing an instrument transformer embedded therein.

27` A substation as defined in claim 1 including a lightning arrester having an entry end and a grounded end and being embedded in an enclosure of synthetic resin, the wall thickness of said enclosure decreasing from the entry end to the grounded end.

28. A substation as defined in claim 1 including a lightning arrester formed a's a solid of revolution, and a bus bar in the axis of said lightning arrester.

29. A substation as defined in claim 1 comprising wheels at the devices and couplings of the station and horizontal rails supporting said wheels.

30. A substation as defined in claim 1 comprising vertical bus bars.

31. A substation as defined in claim 1 comprising horizontal bus bars.

32. A substation as defined in claim 1 comprising a vertical support, one side of said support carrying the parts of the substation, and vertical threaded spindles for displacing said parts.

33. A substation as defined in claim 1 comprising a vertical support carrying the parts of the substation on both sides in form of a U.

34. A substation as defined in claim 1 including cables for the incoming and outgoing high voltage lines, the station and terminals -of said cables being fully metalenclosed.

35. A substation as defined in claim l wherein at least part 0f said electrical conductors are bus bars having approximately spherical terminals.

36. A high voltage substation as defined in claim 1, comprising revolvable members coupling said high voltage devices, means for actuating said revolvable coupling members from the outside, and means transmitting the rotary motion of said coupling members into translatory motion of said high voltage devices.

37. A high voltage substation comprising a plurality of metal clad, electrically connected high voltage devices mechanically coupled for ready rem-oval and replacement of individual devices, each of said devices com prising a form-stable insulating block of asynthetic resin, an electric conductor firmly and substantially completely embedded in -said block, and an outer metal covering, said insulating blocks being joined together slugwise to form a substantially continuous insulation leaving only narrow gaps between the adjoining faces of said blocks, and said metal coverings forming a grounded metal sheath enclosing the substation, said gaps being filled with an insulating fluid.

38. A substation as defined in claim 37, wherein said fluid insulating material is a member of the group consisting of fluoroethers, fluoro-t-amines, and phenylindan.

39. A high voltage substation comprising a plurality of metal clad, electrically connected high voltage devices mechanically coupled for ready removal and replacement of individual devices, each of said devices comprising a form-stable insulating block of a synthetic resin, an electric conductor firmly and substantially completely embedded in said block, and an outer metal covering, said insulating blocks lbeing joined together plugwise to form a substantially continuous insulation leaving only narrow gaps between the adjoining faces of said blocks, and said metal coverings forming a grounded metal sheath enclosing the substation, said gaps filled with air under pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,089,052 Calvert Aug. 3, 1937 2,518,665 Collard Aug. 15, 1950 2,588,436 Violette Mar. 11, 1952 FOREIGN PATENTS 575,511 Great Britain Feb. 21, 1946