Dead tank high-voltage circuit breaker having an electrode for measuring the voltage at its high-voltage terminal and a method for measuring voltage with the electrode

Abstract

The invention relates to a dead tank high-voltage circuit breaker (1), having a housing (2) and at least one feed-through (3) in the housing (2) for an electrical conductor (4), and having at least one electrode (5) for shielding the electrical conductor (4) from the housing (2). The at least one electrode (5) is at floating potential and is designed to measure the voltage at a high-voltage terminal of the dead tank high-voltage circuit breaker (1). The invention also relates to a method for measuring voltage with the electrode (5).

Description

[0001] Description

[0002] Dead-tank high-voltage circuit breaker with electrode for measuring the voltage at its high-voltage terminal and method for measuring voltage with the electrode

[0003] The invention relates to a dead-tank high-voltage circuit breaker, comprising a housing and at least one bushing on the housing for an electrical conductor, and at least one electrode for shielding the electrical conductor from the housing. Furthermore, the invention relates to a method for measuring voltage at the dead-tank high-voltage circuit breaker.

[0004] Dead-tank high-voltage circuit breakers are used for switching voltages and currents in the range of up to 1200 kV and in the range of up to several thousand amperes. Interrupter units in a dead tank, i.e. in a grounded housing, e.g. made of metals such as cast iron or steel, are designed to close and / or open a current path, i.e. to switch. The housing is filled with an insulating gas, e.g. SF6 and / or clean air. An interrupter unit comprises, e.g., at least one rated current contact and at least one arcing contact, or a vacuum interrupter with, in particular, two contact pieces. When the contacts are switched, arcs occur which are extinguished by blowing switching gas, e.g., via a blow nozzle made of Teflon and / or plastic, or extinguish in a vacuum. The movable contacts of the interrupter unit are moved by a drive during switching. Drives are, for example,Spring-loaded mechanisms, motors, and / or manual operators. An operator is attached, for example, to the housing of the dead-tank high-voltage circuit breaker. The housing is set up, for example, on a frame in a building or outdoors. The dead-tank high-voltage circuit breaker switches, for example, overhead lines, consumers such as machines, power generators, and / or parts of power grids on and / or off. Power lines are connected to the dead-tank high-voltage circuit breaker via contact flanges, with each current flange being electrically connected to the interrupter unit via an electrical conductor, e.g. in the form of a busbar in a bushing. The bushings are arranged on the housing of the dead-tank high-voltage circuit breaker. The electrical conductors are led out of the housing to the outside via the bushings.

[0005] In order to prevent electrical arcing between the electrical conductors and the housing, e.g. made of metal, electrodes are arranged in the area of ​​the bushings in the housing of the dead tank high-voltage circuit breaker. The electrodes are permanently electrically connected to earth potential to shield the live conductors. A voltage tap or voltage measurements are not provided for on the electrodes in the prior art, cf. in particular DE 19856775 A1. Separate devices, such as inductive voltage transformers and / or capacitive voltage dividers, are used to measure voltage in the high-voltage network. The separate devices for voltage measurement entail additional costs and space consumption in the voltage field or on the dead tank. A measurement signal is transmitted from the devices in the same way as to the measuring control room, where it is processed and used to control the dead tank high-voltage circuit breaker.

[0006] The invention is based on the object of specifying an improved dead-tank high-voltage circuit breaker with an electrode for measuring the voltage at its high-voltage connection and a method for measuring voltage with the electrode, in particular with low costs and / or reduced space requirements compared to voltage measurements with separate measuring devices. This object is achieved according to the invention by a dead-tank high-voltage circuit breaker with the features of claim 1 and / or a method for measuring voltage at a dead-tank high-voltage circuit breaker, in particular a previously described dead-tank high-voltage circuit breaker, according to claim 11.Advantageous embodiments of the dead-tank high-voltage circuit breaker according to the invention and / or of the method according to the invention for voltage measurement on a dead-tank high-voltage circuit breaker, in particular a previously described dead-tank high-voltage circuit breaker, are specified in the subclaims. Subject matter of the main claim can be combined with features of subclaims, and features of the subclaims can be combined with one another.

[0007] A dead-tank high-voltage circuit breaker according to the invention comprises a housing and at least one bushing on the housing for an electrical conductor, and at least one electrode for shielding the electrical conductor from the housing. The at least one electrode is at a floating potential. Because the at least one electrode is not at ground potential but at a floating potential, a voltage of a high-voltage connection of the dead-tank high-voltage circuit breaker or the voltage at the electrical conductor which is arranged in the bushing with the at least one electrode can be measured at the at least one electrode. This saves on an additional measuring device, in particular a voltage transformer and / or a voltage divider, which is associated with cost and space savings. Space is saved in the span for an additional measuring device and / or on the dead tank.This makes a compact design possible.

[0008] The at least one electrode can be arranged in the at least one bushing, in particular an outdoor bushing. This has the advantages described above. At least one interrupter unit can be arranged in the housing, which is connected to at least two electrical conductors, each of which is led out of the housing through a bushing, in particular for connecting a high voltage in the range greater than and / or equal to 52 kilovolts. In this way, a voltage can be measured on one or both electrical conductors, and the function of the at least one interrupter unit can be checked, in particular the on and off switching state. The interrupter unit can also be switched depending on the occurrence of overvoltages on the electrical conductors.The measured voltages can be processed directly on site or transmitted to a control room and / or used to regulate or control the power grid and / or the interrupter unit.

[0009] The at least one electrode can be electrically insulated from the housing and electrically connected to ground potential, in particular via discrete capacitances. With the at least one electrode at floating potential, which is insulated from the housing and coupled to ground potential via discrete capacitances, the stray capacitance between the conductor and the electrode, together with the discrete capacitances, forms a voltage divider that can be used to measure the high-voltage potential.

[0010] An electrical circuit with at least one voltage divider can be included for measuring a high-voltage potential at the electrical conductor, wherein the voltage divider can comprise, in particular, discrete capacitances and at least one stray capacitance between the electrical conductor and the at least one electrode. This makes it possible to simply and cost-effectively measure a voltage of a high-voltage terminal of the dead-tank high-voltage circuit breaker via the electrode, or to measure the voltage at the electrical conductor arranged in the bushing with the at least one electrode.

[0011] The electrical circuit for measuring a high-voltage potential can include overvoltage protection elements, particularly for protecting connected measuring equipment. This provides effective protection against irreversible damage when overvoltage peaks occur.

[0012] The voltage divider can be designed in such a way, in particular with a transmission ratio, that a low voltage is applied to the particularly discrete capacitances when a high voltage is applied to the dead-tank high-voltage circuit breaker, in particular a low voltage in the range of up to 1000 volts.

[0013] The voltage divider's ratio can be selected so that a low voltage, typical for further processing, is applied to the discrete capacitors. The potential increase of the electrode relative to the housing is negligible, so that the electric field strengths occurring at the highly stressed elements of the dead-tank high-voltage circuit breaker do not change significantly, and the functionality of the electrode is maintained.

[0014] Due to the modified potential connection of the electrode, a non-conventional voltage transformer is integrated into the dead-tank high-voltage circuit breaker. This provides voltage measurement at each high-voltage connection of the circuit breaker, allowing function and load to be continuously monitored. Any overvoltages that occur are recorded, making additional data available for further investigations. For example, measurements of temporarily occurring overvoltages can be used in an aging model for the high-voltage insulation. The dead-tank high-voltage circuit breaker can be designed for switching in the range greater than or equal to 52 kV, i.e. for high voltages.

[0015] The at least one electrode can be arranged in a cylindrical shape around the respective electrical conductor in a contact-free manner, particularly symmetrically. This provides a good option for voltage measurement without voltage flashovers and voltage surges, particularly at the electrode and / or the housing, and a compact design of the dead-tank high-voltage circuit breaker is possible.

[0016] The at least one electrode, in particular made of copper, aluminum, and / or steel, can be attached to an insulator of the respective bushing, in particular made of ceramic, silicone, and / or a composite material, and / or can be attached to the housing of the dead-tank high-voltage circuit breaker, in particular a metallic tank, in particular attached by screwing, welding, clamping, and / or gluing, electrically insulated from the housing, which can be connected to ground potential. This enables a compact, mechanically and temporally stable structure.

[0017] A method according to the invention for measuring a voltage on a dead-tank high-voltage circuit breaker as described above comprises that the at least one electrode for shielding the electrical conductor from the housing at a floating potential measures a voltage on a high-voltage terminal of the dead-tank high-voltage circuit breaker, in particular continuously.

[0018] An overvoltage can be detected by measuring the voltage at the high-voltage terminal of the dead-tank high-voltage circuit breaker.

[0019] The occurrence of overvoltage and / or its time course can be used to determine the aging of a high-voltage insulation of the dead-tank high-voltage circuit breaker.

[0020] The advantages of the method according to the invention for a voltage measurement on a previously described dead-tank high-voltage circuit breaker according to claim 11 are analogous to the previously described advantages of the dead-tank high-voltage circuit breaker according to the invention according to claim 1 and vice versa.

[0021] In the following, embodiments of the invention are shown schematically in the figures and described in more detail below.

[0022] The

[0023] Figure 1 shows a schematic sectional view of a dead-tank high-voltage circuit breaker 1 according to the invention, with a housing 2 and with two bushings 3 on the housing 2 for electrical conductors 4, wherein the conductors 4 are each surrounded by an electrode 5 for shielding at a floating potential, and

[0024] Figure 2 shows a schematic enlarged sectional view of the electrode 5 in a feedthrough 3 .

[0025] Figure 1 shows a schematic side view of a dead-tank high-voltage circuit breaker 1 according to the invention in a sectional view. In the exemplary embodiment in Figure 1, the dead-tank high-voltage circuit breaker 1 comprises a housing 2 with two bushings 3 which are arranged on the housing 2. At least one interrupter unit 6 for interrupting and / or closing at least one current path is arranged in the housing 2. The interrupter unit 6 is connected via electrical conductors 4 to connections, for example, to an electrical power grid, to power generators, power storage devices, electrical consumers and / or high-voltage lines. The electrical conductors 4 are each spatially enclosed by a bushing 3 in order to electrically connect the interrupter unit 6 inside the housing 2 to the electrical connections outside the housing 2 via the electrical conductors 4.

[0026] The housing 2 of the dead-tank high-voltage circuit breaker 1 is, for example, a metal housing, in particular made of steel, cast iron and / or aluminum. The particularly tank-shaped housing

[0027] 2 is arranged and / or mounted on a frame 8, and is installed in a building or outdoors. In particular, the tank is, for example, cylindrical and gas-tight. The housing 2 is filled with an insulating gas, e.g., SF6, CO2, and / or purified, dried air, i.e., clean air.

[0028] The interrupter unit 6 is arranged in the housing 2. The interrupter unit 6 comprises, for example, at least one conventional circuit breaker with rated current contact pieces and arcing contact pieces, and / or at least one vacuum interrupter. The movable contact pieces of the interrupter unit 6 are driven by a drive 7, e.g., a motor, a hand crank, and / or a spring-loaded drive. The drive 7 is arranged, for example, in the housing 2, or in a separate housing on the housing 2 and / or on the frame 8, and is mechanically connected to the movable contact pieces via elements of a kinematic chain, such as a gear and / or a switching rod.

[0029] The bushings 3 are attached to the housing 2, e.g., via flanges, in particular in a gas-tight manner, e.g., screwed, welded, glued and / or clamped. Through the bushings

[0030] 3, the conductors 4, electrically connected to the interrupter unit 6, are led from the interior of the housing 2 to the exterior. The bushings are gas-tight and filled with the insulating gas, e.g., SF6, CO2, and / or purified, dried air, i.e., clean air. The bushings 3 comprise, for example, an insulator 12, in particular made of ceramic, silicone, and / or a composite material. The insulator 12 is, for example, cylindrical, with ribs on the outer surface to extend leakage current paths. The bushing 3 is open toward the housing 2 and, on the opposite side, gas-tight, closed toward the outer terminals, with conductors led to the exterior.

[0031] 4.

[0032] In the feedthrough 3, at least one conductor 4 is arranged at a distance from the insulator 12, e.g., congruent to the cylindrical axis of the insulator 12, and at least in one region is spatially spaced from the electrode 5. Conductors 4 are made, e.g., of copper, aluminum, and / or electrically highly conductive steel, and / or in the shape of a rod or busbar. The electrodes 5 are made, e.g., of copper, aluminum, and / or electrically highly conductive steel, with, e.g., a cylindrical or truncated cone shape. Conductor 4, insulator 12, and electrode 5 of a respective feedthrough 3 are arranged, e.g., on a congruent axis, which represents the longitudinal axis of the conductor 4, insulator 12, and electrode 5, respectively. The electrode

[0033] 5 is arranged at a distance from the conductor 4 and the insulator 12, in the insulator 12, spatially enclosing the conductor 4, via electrically insulating spacer elements or spacers 15, for example, attached to the insulator 12, as shown in Figure 1, or to the tank housing 2 of the dead-tank high-voltage circuit breaker 1, as shown in the embodiment of Figure 2.

[0034] 1 and 2 are otherwise identical, with Figure 2 showing an electrode 5 in a schematically enlarged sectional view in an associated bushing 3. The electrode 5 is at a floating potential and is arranged at a distance around the associated conductor 4 for electrical shielding. By arranging the electrode 5 at a distance around the electrical conductor 4, at a floating potential and not at ground potential, a voltage of a high-voltage connection of the dead-tank high-voltage circuit breaker 1 or of the conductor 4 can be measured directly at the at least one electrode 5. This makes it possible to save on an additional measuring device, in particular a voltage transformer and / or a voltage divider outside the dead-tank high-voltage circuit breaker, which is associated with cost and space savings. A compact design is thus possible.

[0035] The electrode 5, which is at a floating potential, is electrically insulated from the housing 2 and coupled to earth potential via at least one discrete capacitance 9. A stray capacitance 10 between the electrode 5 and the associated electrical conductor 4 forms, with the at least one discrete capacitance 9, a voltage divider which is used to measure the high-voltage potential at the electrical conductor 4. To protect connected measuring technology, an overvoltage protector 13, for example, is integrated into the measuring tap on the dead-tank high-voltage circuit breaker 1. The transformation ratio of the voltage divider is, for example, selected such that a voltage customary for further processing is applied to the at least one discrete capacitance 9, in particular in the range from below one volt up to one volt, and / or in the range from one volt up to several hundred volts.The potential increase of the electrode 5 relative to the housing 2 is thus negligible, so that the electrical field strengths occurring at the electrically highly stressed parts or elements of the dead-tank high-voltage circuit breaker 1 do not change significantly and the shielding functionality of the electrode 5 for the conductor 4 is retained.

[0036] The previously described electrical circuit 11 further comprises, for example, a terminating resistor 14, in particular in the range from a few ohms up to a few megaohms, for measuring the voltage across the at least one discrete capacitance 9. Due to the modified potential connection of the electrode 5 at a floating potential, arranged at a distance around the conductor 4, a non-conventional voltage transformer is integrated in the dead-tank high-voltage circuit breaker 1. With a corresponding design on each conductor 4 in a corresponding bushing 3, a voltage measurement is available at each high-voltage connection of the dead-tank high-voltage circuit breaker 1, whereby function and load can be permanently monitored. Any overvoltages that occur are recorded, so that additional data is available for further processing. For example,Measurements of temporarily occurring overvoltages are used for an aging model of the high-voltage insulation. Monitoring and control of the switching of the dead-tank high-voltage circuit breaker 1 or of connected high-voltage lines and / or devices is enabled.

[0037] The measurement data can be processed and / or sent locally, e.g., wirelessly or by cable, particularly via the intranet and / or internet, to a central control room and / or data processing facilities. There, the data can be stored, processed, and / or used for control purposes, or, e.g., for predictive maintenance.

[0038] The previously described embodiments can be combined with one another and / or can be combined with the prior art. For example, a housing 2 of a dead-tank high-voltage circuit breaker 1 can contain a plurality of interrupter units 6. These interrupter units can be electrically connected to one another and / or connected via at least two or more conductors 4 in, for example, bushings 3, in particular via external connections, to high-voltage conductors and / or networks, consumers and / or power generators. Further high-voltage devices, such as switching resistors, can also be provided in the housing 2 or on the housing 2, e.g. in separate housings. An electrode 5 for voltage measurement can be provided around a conductor 4, or several electrodes, e.g. at different locations in the bushing and / or in the housing 2, and / or outside the housing 2, e.g. in the open air.A dead-tank high-voltage circuit breaker 1 may also comprise several housings, each containing interrupter units 6, bushings 3, electrical conductors 4 and / or electrodes 5 at free potential.

[0039] Reference symbol list

[0040] 1 dead-tank high-voltage circuit breaker

[0041] 2 housings

[0042] 3 Implementation

[0043] 4 electrical conductors

[0044] 5 Electrode

[0045] 6 Breaker unit

[0046] 7 Drive

[0047] 8 frame

[0048] 9 discrete capacity

[0049] 10 scattering capacity

[0050] 11 electrical circuit

[0051] 12 Insulator

[0052] 13 Surge protection

[0053] 14 Terminating resistor

[0054] 15 insulating spacers

Claims

Patent claims 1. Dead-tank high-voltage circuit breaker (1), with a housing (2) and with at least one bushing (3) on the housing (2) for an electrical conductor (4), and with at least one electrode (5) for shielding the electrical conductor (4) from the housing (2), characterized in that the at least one electrode (5) is at floating potential.

2. Dead-tank high-voltage circuit breaker (1) according to claim 1, characterized in that the at least one electrode (5) is arranged in the at least one bushing (3), in particular an outdoor bushing.

3. Dead-tank high-voltage circuit breaker (1) according to one of the preceding claims, characterized in that at least one interrupter unit (6) is arranged in the housing (2), which is connected to at least two electrical conductors (4), each of which is led out of the housing (2) through a bushing (3), in particular for connecting a high voltage in the range greater than and / or equal to 52 kilovolts.

4. Dead-tank high-voltage circuit breaker (1) according to one of the preceding claims, characterized in that the at least one electrode (5) is constructed to be electrically insulated from the housing (2) and is electrically connected to earth potential via, in particular, discrete capacitors (9).

5. Dead-tank high-voltage circuit breaker (1) according to claim 4, characterized in that an electrical circuit (11) with at least one voltage divider is included for Measurement of a high voltage potential on the electrical conductor (4), wherein the voltage divider comprises the in particular discrete capacitances (6) and at least one stray capacitance (10) between see the electrical conductor (4) and which comprises at least one electrode (5).

6. Dead-tank high-voltage circuit breaker (1) according to claim 5, characterized in that the electrical circuit for measuring a high-voltage potential comprises elements for overvoltage protection, in particular for protecting connected measuring technology.

7. Dead-tank high-voltage circuit breaker (1) according to one of claims 5 or 6, characterized in that the voltage divider is designed in such a way, in particular with a transmission ratio, that a low voltage is applied to the in particular discrete capacitors (9) when high voltage is applied to the dead-tank high-voltage circuit breaker (1), in particular a low voltage in the range of up to 1000 volts.

8. Dead-tank high-voltage circuit breaker (1) according to one of the preceding claims, characterized in that the dead-tank high-voltage circuit breaker (1) is designed for switching in the range greater than or equal to 52 kV.

9. Dead-tank high-voltage circuit breaker (1) according to one of the preceding claims, characterized in that the at least one electrode (5) is arranged in particular cylindrically around the respective electrical conductor (4) in a contact-free manner, in particular symmetrically.

10. Dead-tank high-voltage circuit breaker (1) according to one of the preceding claims, characterized in that the at least one electrode (5), in particular made of copper, aluminum and / or steel, is fastened to an insulator (12) of the respective bushing (3), in particular made of ceramic, silicone and / or a composite material, and / or is fastened to the housing (2) of the dead-tank high-voltage circuit breaker (1), in particular a metallic tank, in particular fastened by screwing, welding, clamping and / or gluing, electrically insulated from the housing (2) which is connected to ground potential.

11. Method for voltage measurement on a dead-tank high-voltage circuit breaker (1) according to one of the preceding claims, characterized in that the at least one electrode (5) for shielding the electrical conductor (4) from the housing (2) at a floating potential measures a voltage at a high-voltage terminal of the dead-tank high-voltage circuit breaker (1), in particular continuously.

12. Method according to claim 11, characterized in that an overvoltage is detected by measuring the voltage at the high-voltage terminal of the dead-tank high-voltage circuit breaker (1).

13. Method according to claim 12, characterized in that the occurrence of overvoltage and / or its temporal progression is used to determine the aging of a high-voltage insulation of the dead-tank high-voltage circuit breaker (1).

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