Rc arrangements for switching inductive currents, using high-voltage vacuum switches

Abstract

The invention relates to the wiring of electric devices, in particular high-voltage switching devices, for the high-voltage energy transfer using RC arrangements. The invention allows vacuum switching devices to be used for inductor switching applications in the high-voltage range >= 72.5 kV.

Description

[0001] Description

[0002] RC arrangements for switching inductive currents with high-voltage vacuum switches

[0003] The invention relates to the wiring of electrical devices, in particular high-voltage switching devices, for high-voltage energy transmission with RC arrangements.

[0004] When switching small inductive currents, such as those encountered in choke applications in high-voltage networks (>= 72.5 kV), special protective measures are necessary. This switching task poses the risk that transient overvoltages could destroy substation components. The choke itself is particularly exposed to a certain risk. Gas switches and vacuum switchgear, for example, are suitable switching media.

[0005] SF6 circuit breakers are predominantly used in high-voltage networks. In these applications, the gas circuit breakers are not operated without additional protective measures. These measures serve to reduce the overvoltages that occur during the switching process.

[0006] Until now, reactor switching applications in high-voltage grids (>= 72.5 kV) have been served by a combination of an electronic control unit (which controls the exact moment of closing or opening) and an SF6 circuit breaker with a single-pole drive. This solution is cost-intensive, requires increased commissioning effort, and carries the risk that the power switching data stored in the control unit, such as the breaker's operating times, could change over the course of operation—over decades. This could alter the optimal switching time and impair the function of the arrangement of the single-pole-driven circuit breaker and electronic control unit.The invention is based on the problem of providing solutions that enable the use of vacuum switching devices instead of gas switches in the high-voltage range (>= 72.5 kV) and, furthermore, of multi-pole switching devices for choke switching applications.

[0007] The problem is solved by a device for electrical high-voltage energy transmission comprising the features of claim 1.

[0008] The use of an RC filter circuit (a series connection of resistor R and capacitor C) can significantly reduce the impact of transient overvoltages. Such a solution has been used in medium-voltage systems for many years and is therefore state-of-the-art. Consequently, RC filter circuit components are also available for the medium-voltage level.

[0009] By transferring this technology to higher voltage levels (>= 72.5 kV), the use of vacuum switching devices instead of gas switches for reactor switching applications in the high-voltage range becomes possible.

[0010] The RC filter circuit elements can be implemented by interconnecting existing discrete RC components (e.g., RC elements in a metal-encapsulated housing ("can") with oil insulation), as already used in medium-voltage systems. Alternatively, the RC elements can be integrated into existing or newly designed high-voltage components for gas-insulated (GIS) or air-insulated (AIS) applications.

[0011] The RC filter circuits can be advantageously integrated into existing or newly designed high-voltage elements, or the existing high-voltage components can be expanded or supplemented with corresponding components. The advantage here is that, thanks to their integration into the high-voltage components, the RC elements do not require separate outdoor-proof housings (e.g., metal-enclosed housings with bushings). This results in cost and space savings. Multi-pole switchgear can be controlled with a single drive.

[0012] Advantageous further developments of the invention are specified in the subclaims.

[0013] The invention is explained in more detail below as an embodiment to the extent necessary for understanding with reference to figures.

[0014] Showing:

[0015] Fig. 1 shows a three-pole, gas-insulated high-voltage device according to the invention with individual resistance discs and capacitors,

[0016] Fig. 2a a single-pole high-voltage cast resin bushing according to the invention with RC circuits,

[0017] Fig. 2b a three-pole high-voltage cast resin bushing according to the invention with RC circuits,

[0018] Fig. 3 a high-voltage bushing according to the invention in two embodiments

[0019] Fig. 4a a high-voltage bushing according to the invention with RC elements integrated into the coupling,

[0020] Fig. 4b shows RC element discs arranged concentrically to the conductor according to the invention,

[0021] Fig. 5a shows a high-voltage circuit breaker according to the invention with RC elements integrated into the insulating supports on the drive side,

[0022] Fig. 5b shows a high-voltage circuit breaker according to the invention with RC elements integrated into the insulating supports on the fixed contact side,

[0023] Fig. 6 Variants of combinations of RC elements according to the invention, Fig. 7 a first outdoor-insulated high-voltage arrester housing according to the invention with individual resistance discs and capacitors,

[0024] Fig. 8 shows a second outdoor-insulated high-voltage arrester housing according to the invention with individual resistor discs and capacitors,

[0025] Fig. 9a a live tank circuit breaker according to the invention with integrated RC elements,

[0026] Fig. 9b shows RC element discs arranged concentrically to the shift rod according to the invention,

[0027] Fig. 10 shows a dead-tank circuit breaker according to the invention with RC elements integrated into the bushing and Fig. 11 shows a dead-tank circuit breaker according to the invention with RC elements integrated into the support.

[0028] In the figures, like designations refer to like elements.

[0029] The invention can be used in gas insulated applications (GIS) which fall into the category of boiler applications.

[0030] In the gas-insulated high-voltage device shown in Fig. 1, which can be single-pole or multi-pole, a conventional arrester is modified in such a way that instead of arrester resistors, such as metal oxide (MO) resistors, individual resistance discs R and capacitors C are arranged.

[0031] Figures 2a and 2b show a single-pole cast resin bushing and a three-pole cast resin bushing, respectively, in which the RC elements are integrated in such a way that they are cast in the cast resin. In this case, a conductor 22 subjected to high voltage is connected to ground M via a respective RC element. A cast resin bushing according to the invention can be combined with an LPIT - Low Power Instrument Transformer. The high-voltage bushing / outlet 23 of a gas-insulated switchgear shown in Figure 3 shows two designs in which the RC elements are arranged parallel to the bushing. As shown on the right in Figure 3, the RC elements can be integrated into the bushing's cover, either on the inner surface of the bushing or in the solid material (ceramic, composite, silicone, etc.) of the bushing.As shown in Fig. 3 on the left, the RC elements can be stacked in a separate cover 19, whereby gas, liquid or solid insulation can be used for the RC elements.

[0032] In the high-voltage bushing / outlet 23 of a gas-insulated switchgear shown in Fig. 4a, the RC elements are integrated into the bushing's cover, with the conductor 22 being connected via the RC elements to the electrode E connected to ground M or to the outer casing of the bushing connected to ground M. The RC elements can be encapsulated in cast resin. The RC elements can be arranged as coaxial elements stacked around the conductor 22, as shown in Fig. 4b. In the embodiment according to Fig. 4a, the diameter and / or length of the area of ​​the bushing / outlet where the RC elements are arranged can be enlarged compared to a conventional bushing / outlet.

[0033] In the high-voltage circuit breaker shown in Fig. 5a, RC elements are arranged in the insulating insulator on the drive side of an interrupter unit UE. In the high-voltage circuit breaker shown in Fig. 5b, RC elements are arranged in the insulating insulator on the fixed contact side of an interrupter unit UE. The RC elements, which are connected in series between high voltage HV and ground M, can be cast into the insulating insulator, providing solid insulation. The RC elements can be arranged in the gas space parallel to the insulator material of the insulating insulator.

[0034] Fig. 6 shows combination variants of RC elements according to the invention. The RC circuit can be implemented in various ways depending on the design and application, for example, alternating small RC elements, a large R and a large C element, various combinations of R and C elements (e.g., 2xR, 2xO), symmetrical or asymmetrical.

[0035] The invention can be used in outdoor isolated applications (AIS).

[0036] In the embodiment shown in Fig. 7, in an outdoor insulated high-voltage arrester housing, instead of the conventional arrester resistors, such as metal oxide (MO) resistors, individual resistor discs R and capacitors C are arranged in a stacked manner in a gas-, liquid- or solid-insulated manner.

[0037] In the embodiment shown in Fig. 8, in an outdoor-insulated high-voltage arrester housing, instead of conventional arrester resistors, such as metal oxide (MO) resistors, individual resistor discs R and capacitors C are arranged in an insulated manner according to the invention. The resistor discs R and the capacitors C are spaced from the insulating housing 13 that concentrically encloses them by means of GRP rods arranged concentrically and evenly around them.

[0038] The live tank circuit breaker shown in Fig. 9a can be single-pole or multi-pole, in particular three-pole. An interrupter unit UE in the coupling is carried by a base 16 via an insulating insulator column 25 and can be actuated by a drive 17 and a gear housed in the base 16 via an insulating switching rod 18 arranged in the insulator column. In the interrupter unit shown on the left in Fig. 9a, RC elements are arranged in the insulator column 25 next to the switching rod. In the interrupter unit shown on the right in Fig. 9a, a separate RC column is arranged in a separate coupling 19 next to an insulator column 25 with switching rod 18. RC elements with gas, liquid or solid insulation can be arranged in the RC column.

[0039] In the interrupter unit shown centrally in Fig. 9a, as shown in more detail in plan view in Fig. 9b, RC elements 7 are arranged as RC discs stacked concentrically to the switching rod 18 in the support column.

[0040] In the dead-tank circuit breaker shown in Fig. 10, an interrupter unit UE is fastened by means of insulating supports 20 in a housing connected to ground M and can be actuated by a drive 17. RC elements 7 are integrated in a bushing 23. The bushing shown on the left in Fig. 10 may be provided by a high-voltage bushing / exit described for Fig. 4. The bushing 23 shown on the right in Fig. 10 may be provided by a high-voltage bushing / exit described for Fig. 3.

[0041] In the dead-tank circuit breaker shown in Fig. 11, an interrupter unit UE is mounted in a housing connected to ground M by means of insulating supports 20. RC elements 7 are integrated into the insulating supports facing away from the drive 17 on the fixed contact side of the interrupter unit. RC elements 7 can be integrated into the insulating supports facing the drive on the drive side of the interrupter unit.

[0042] A cast resin bushing 24 corresponding to the design shown in Fig. 2a is arranged between the bushing 23 shown on the right in Fig. 11 and the housing flange. RC elements are integrated into the cast resin bushing in such a way that they are encapsulated in the cast resin. The cast resin bushing can be combined with an LPIT - Low Power Instrument Transformer.

[0043] The dead-tank applications shown in Figures 10 and 11 fall into the category of boiler applications. The dead-tank circuit breaker shown in Figures 10 and 11 can be single-pole or multi-pole, particularly three-pole.

[0044] An interrupter unit UE may comprise a high-voltage switch, in particular a high-voltage vacuum switch.

[0045] The inventive wiring of electrical devices for high-voltage energy transmission with RC arrangements forms a protective circuit for high-voltage switching devices, in particular high-voltage vacuum switches.

[0046] High voltage in the sense of the invention is understood to mean a voltage of 72.5 kV (kilovolts) and higher, including direct current, alternating current and, if three-pole, three-phase current.

[0047] The present invention has been explained in detail for illustrative purposes using specific embodiments. Elements of the individual embodiments can also be combined with one another. The invention is therefore not intended to be limited to individual embodiments, but is limited solely by the appended claims. List of Reference Symbols

[0048] 1 - Exhaust opening

[0049] 2 - Pressure relief unit

[0050] 3 - Compression spring

[0051] 4 - Sealing ring

[0052] 5 - Putty

[0053] 6 - Metallic filler piece

[0054] 7 - RC combination

[0055] 8 - Grab bar, glass-fiber reinforced plastic (GRP)

[0056] 9 - Holding plate, glass fiber reinforced plastic (GRP)

[0057] 10 - Porcelain case

[0058] 11 - Aluminum flange

[0059] 12 - End fitting with high-voltage connection

[0060] 13 - Silicone shielding

[0061] 14 - GRP rods

[0062] 15 - End fitting with foot, mass

[0063] 16 - Base, Gearbox

[0064] 17 - Drive

[0065] 18 - Switch rod, insulating rod

[0066] 19 - Throw

[0067] 20 - Insulating supports, supports

[0068] 21 - Base

[0069] 22 - Ladder

[0070] 23 - Implementation

[0071] 24 - Cast resin bushing

[0072] 25 - Supporting column

[0073] AIS - Air Insulated Switchgear

[0074] C - capacitor, capacitance

[0075] E - Electrode

[0076] DT - Dead Tank

[0077] GIS - Gas Insulated Switchgear

[0078] HV - high voltage

[0079] LPIT - Low Power Instrument Transformer

[0080] LT - Live Tank

[0081] M - mass, earth potential MO - metal oxide

[0082] R - electrical resistance

[0083] UE - Interrupter unit

Claims

Patent claims 1. Device for the electrical high-voltage energy transmission in which the high voltage (HV) is greater than or equal to 72.5 kilovolts, characterized in that a series circuit comprising at least one electrical resistor R and at least one capacitor C is arranged between a conductor (22) carrying the high voltage (HV) and ground (M).

2. Device according to claim 1, characterized in that it is provided by a high-voltage feedthrough / outlet (23).

3. Device according to claim 2, characterized in that it is designed as a cast resin bushing (24).

4. Device according to claim 3, characterized in that the cast resin feedthrough is combined with a Low Power Instrument Transformer (LPIT).

5. Device according to claim 2, characterized in that the series circuit comprising at least one electrical resistor R and at least one capacitor C is integrated into the sleeve (19) of the bushing.

6. Device according to claim 2, characterized in that the series circuit comprising at least one electrical resistor R and at least one capacitor C are arranged in a separate cover (19) parallel to the bushing (23).

7. Device according to claim 1, characterized in that it is provided by a high-voltage circuit breaker and the series circuit comprising at least one electrical resistor R and at least one capacitor C is arranged in the insulating support (20) on the drive side or the fixed contact side of an interrupter unit UE.

8. Device according to claim 1, characterized in that it is provided by a live tank circuit breaker and the series circuit comprising at least one electrical resistor R and at least one capacitor C are arranged parallel to the support column (25).

9. Device according to claim 1, characterized in that it is provided by an arrester in which the series circuit comprising at least one electrical resistor R and at least one capacitor C is arranged instead of the arrester resistor.

10. Device according to one of the preceding claims, characterized in that it has a vacuum switching device as the interrupter unit UE.

11. Device according to one of the preceding claims, characterized in that it is designed to be multi-pole.

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