Voltage switching control device and method with indicated lockout mode

Abstract

The application discloses a voltage switching control device and method with an indicating locking mode, which adds an indicating lamp in the circuit of the normally closed contact of the isolating switch in the direct current loop. In normal operation, the indicating lamp can cooperate with the starting circuit of the normally open contact of the isolating switch to indicate the actual position of the isolating switch. When the primary equipment of the isolating switch needs to be replaced or overhauled, the secondary circuit wiring changes or is reconnected, the correctness of the secondary circuit wiring where the auxiliary contact of the isolating switch is located can be checked in the main control room in time, and the working efficiency is improved. Meanwhile, the locking circuit is added in the alternating current circuit of the double bus voltage switching device. In normal operation, even if the magnetic holding relay and the corresponding contact have problems, the voltage circuit can be ensured to be single. When the isolating switch is replaced and the secondary circuit is reconnected, even if the connection of the normally closed contact of the isolating switch is incorrect, the voltage of the live bus will not return to the off bus during power transmission, and the safety is higher.

Description

Technical Field

[0001] This invention relates to the field of substation circuit technology, and in particular to a voltage switching control device and method with an indication of the blocking mode. Background Technology

[0002] In substations, 220kV busbars mostly adopt a double busbar connection method, and some 110kV and 35kV busbars also adopt a double busbar connection method. The lines or transformers connected to the double busbars can be connected to bus I or bus II through disconnecting switches. When connected to bus I, its voltage circuit must be connected to the secondary voltage circuit of the voltage transformer used by bus I. Similarly, when connected to bus II, its voltage circuit must be connected to the secondary voltage circuit of the voltage transformer used by bus II. This conversion of the secondary voltage circuit is achieved through a voltage switching circuit.

[0003] When the relay used in the voltage switching circuit is a magnetically latching type, once the relay is activated, it will remain in the activated state even if the DC power supply is lost. Only when the disconnecting switch is opened, the normally closed auxiliary contact of the disconnecting switch closes, and the relay return coil is energized will the relay return and disconnect the voltage secondary circuit. When substations upgrade or replace circuit breakers and disconnecting switches, the secondary circuit wiring will be re-installed. Due to the dense wiring of the terminal blocks, incorrect wiring or open circuits may occur, which are not easily detected during inspection. In the wiring diagram of the 220kV circuit breaker terminal box, the wiring of the normally open and normally closed contacts of the disconnecting switch is also in the circuit breaker terminal box.

[0004] After the secondary circuit wiring of the disconnecting switch is completed, a pull-open test is performed on the disconnecting switch. When the disconnecting switch is closed, the voltage switching secondary circuit is connected and the indicator light is lit, which can verify the correctness of the secondary circuit wiring. When the disconnecting switch is opened, the correctness of the circuit cannot be guaranteed because there is no corresponding indicator signal. Due to misalignment, open pressure, or lack of compaction of the normally closed auxiliary contact wiring of the disconnecting switch, the disconnecting switch is opened, but the corresponding voltage secondary circuit is not actually cut off. In practice, when energizing the line or testing another disconnecting switch, as soon as the disconnecting switch is closed, the voltage of the live bus is immediately energized through the voltage switching secondary circuit, endangering personal and equipment safety, and in severe cases, causing project delays and economic losses.

[0005] Reference Figure 1 This is a simplified diagram of a conventional substation with dual busbars. Taking the secondary circuit for line voltage switching as an example, QS11 and QS12 are disconnecting switches connecting bus I and bus II, respectively. Figure 2As shown, 1YQJ4, 1YQJ5, and 1YQJ6 are control DC relays for switching to the secondary circuit of bus section I (TV1), and 2YQJ4, 2YQJ5, and 2YQJ6 are control DC relays for switching to the secondary circuit of bus section II (TV2). When the line is connected to bus section I, closing the QS11 disconnecting switch closes the normally open auxiliary contact of the bus section I disconnecting switch, energizing the operating coils of the corresponding relay groups 1YQJ4, 1YQJ5, and 1YQJ6, starting the relays, illuminating the LED LD1, and simultaneously connecting the normally open contacts of the corresponding relays to the secondary circuit of bus section I voltage. Figure 3 As shown, the device panel will display that it is in operation on bus I (TV). Since 1YQJ4, 1YQJ5, and 1YQJ6 are magnetically latched relays, they will remain in the activated state even if the DC power supply is lost, ensuring the normal operation of the AC voltage circuit. When disconnector switch QS11 is opened, its normally open auxiliary contact on bus I opens, LD1 goes out, the normally closed contact on bus I closes, and the return coils of relays 1YQJ4, 1YQJ5, and 1YQJ6 are energized, causing the relays to return and thus disconnecting the AC secondary circuit of bus I. When the line is connected to bus II, the working principle of relay group 2YQJ4, 2YQJ5, and 2YQJ6 and their corresponding normally open and normally closed contacts is the same as that of 1YQJ4, 1YQJ5, and 1YQJ6. The operating principle of the transformer voltage switching secondary circuit is the same as that of the line.

[0006] When replacing disconnectors QS11 and QS21 with new equipment and rewiring the corresponding secondary circuits, a pull-open test must be performed on the disconnectors to ensure they operate correctly. Simultaneously, the correctness of the voltage switching and other secondary circuits should be verified using indicator lights and the device panel. When the disconnector is closed, the LED illuminates when the voltage switching relay's starting circuit is activated, indicating correct wiring. However, when the disconnector is opened, because there is no indication signal in the relay return circuit, the disconnector can open normally even if the normally closed auxiliary contact wiring is incorrect or not properly secured. Therefore, the test personnel cannot confirm the correctness of the relay return circuit wiring. In this situation, although the disconnector is open, the actual AC voltage circuit is not disconnected, and the corresponding busbar is de-energized. If another energized busbar supplies power to the line or opens / closes a disconnector at this time, the corresponding disconnector on the other busbar will close, and the voltage on the energized busbar will energize the de-energized busbar, seriously endangering personal and equipment safety. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a voltage switching control device with a high level of security and an indicator-locked-out mode.

[0008] To address the aforementioned problems, this invention provides a voltage switching control device with an indication of a lockout mode, comprising a DC circuit and an AC circuit. The DC circuit includes a normally open contact start-up circuit for a bus I disconnect switch, a normally closed contact circuit for a bus I disconnect switch, a normally open contact start-up circuit for a bus II disconnect switch, and a normally closed contact circuit for a bus II disconnect switch. A first indicator light is connected to the normally closed contact circuit for the bus I disconnect switch, and a second indicator light is connected to the normally closed contact circuit for the bus II disconnect switch.

[0009] The first indicator light is used to verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the I bus disconnector is located when the secondary circuit corresponding to the I bus disconnector is rewired; the second indicator light is used to verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the II bus disconnector is located when the secondary circuit corresponding to the II bus disconnector is rewired.

[0010] As a further improvement of the present invention, the first indicator light is also used to indicate the actual position of the I-bus disconnector switch in normal operation, in conjunction with the indicator light of the normally open contact start circuit of the I-bus disconnector switch.

[0011] As a further improvement of the present invention, the second indicator light is also used to indicate the actual position of the II bus disconnector switch in conjunction with the indicator light of the normally open contact start circuit of the II bus disconnector switch during normal operation.

[0012] As a further improvement of the present invention, the first indicator light is a light-emitting diode.

[0013] As a further improvement of the present invention, the second indicator light is a light-emitting diode.

[0014] The present invention also provides a voltage switching control method with an indication of a lockout mode, applied to the aforementioned voltage switching control device with an indication of a lockout mode, comprising the following steps:

[0015] During normal operation, the first indicator light works in conjunction with the indicator light in the normally open contact start circuit of the I bus disconnect switch to indicate the actual position of the I bus disconnect switch;

[0016] When the secondary circuit corresponding to the I bus disconnect switch is rewired, the first indicator light can verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the I bus disconnect switch is located.

[0017] During normal operation, the second indicator light works in conjunction with the indicator light in the normally open contact start circuit of the II bus disconnect switch to indicate the actual position of the II bus disconnect switch;

[0018] When the secondary circuit corresponding to the II bus disconnect switch is rewired, the second indicator light can verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the II bus disconnect switch is located.

[0019] As a further improvement of the present invention, the AC circuit includes a first bus voltage circuit and a second bus voltage circuit. A relay 1JK is provided in the first bus voltage circuit, a normally closed contact of 1JK is provided in the second bus voltage circuit, a relay 2JK is provided in the second bus voltage circuit, and a normally closed contact of 2JK is provided in the first bus voltage circuit.

[0020] The relay 1JK is activated when the normally open auxiliary contact in the I bus voltage circuit is closed, and opens the normally closed contact 1JK in the II bus voltage circuit to cut off the corresponding voltage of the II bus; the relay 2JK is activated when the normally open auxiliary contact in the II bus voltage circuit is closed, and opens the normally closed contact 2JK in the I bus voltage circuit to cut off the corresponding voltage of the I bus.

[0021] As a further improvement of the present invention, relay 1JK and relay 2JK are disposed on the same phase or on different phases.

[0022] As a further improvement of the present invention, the relay 1JK is installed on any phase of the I bus voltage circuit, and the relay 2JK is installed on any phase of the II bus voltage circuit.

[0023] The present invention also provides a voltage switching control method with an indication of a lockout mode, applied to the aforementioned voltage switching control device with an indication of a lockout mode, comprising the following steps:

[0024] When the normally open auxiliary contact in the I bus voltage circuit is closed, the relay 1JK is activated and opens the normally closed contact 1JK in the II bus voltage circuit to cut off the corresponding voltage of the II bus.

[0025] When the normally open auxiliary contact in the II bus voltage circuit is closed, the relay 2JK is activated and opens the normally closed contact 2JK in the I bus voltage circuit, cutting off the corresponding voltage of the I bus.

[0026] The beneficial effects of this invention are:

[0027] The present invention relates to a dual bus voltage switching device and method. By adding an indicator light to the normally closed contact circuit of the isolating switch in the DC circuit, the indicator light can work in conjunction with the normally open contact start circuit of the isolating switch to indicate the actual position of the isolating switch during normal operation. When the primary equipment of the isolating switch needs to be replaced or repaired, and the wiring of the corresponding secondary circuit changes or is rewired, the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the isolating switch is located can be checked in a timely manner in the main control room, thereby improving work efficiency.

[0028] Meanwhile, a blocking circuit is added to the AC circuit of the dual bus voltage switching device. During normal operation, even if the magnetic latching relay and corresponding contacts malfunction, the blocking circuit can still ensure the singleness of the voltage circuit. When the disconnecting switch is replaced and the secondary circuit is rewired, even if the normally closed contact of the disconnecting switch is not wired correctly, the voltage of the energized bus will not return to the de-energized bus when power is supplied, thus improving inherent safety and ensuring the safety of personnel, power grid and equipment.

[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a simplified diagram of a conventional substation with dual busbars.

[0031] Figure 2 Wiring diagram of DC circuit for conventional line dual-bus voltage switching device;

[0032] Figure 3 This is the AC circuit wiring diagram for a conventional dual-bus voltage switching device.

[0033] Figure 4 This is a DC circuit wiring diagram of the line dual-bus voltage switching device in an embodiment of the present invention;

[0034] Figure 5 This is the AC circuit wiring diagram of the dual bus voltage switching device in an embodiment of the present invention. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0036] like Figure 4-5 As shown, this is a voltage switching control device with an indication of the blocking mode in an embodiment of the present invention, including a DC circuit and an AC circuit. The DC circuit includes a normally open contact start-up circuit of the I bus disconnect switch, a normally closed contact circuit of the I bus disconnect switch, a normally open contact start-up circuit of the II bus disconnect switch, and a normally closed contact circuit of the II bus disconnect switch.

[0037] Figure 4In the diagram, +KM and -KM are the positive and negative terminals of the control power supply, GD1 and GD2 are the wiring terminals for the positive and negative terminals of the control power supply, 1Q is a DC air switch used to control the on / off state of the control power supply; the normally open and normally closed auxiliary contacts of the I and II bus disconnect switches are taken from the auxiliary contacts that are switched during the operation of the disconnect switches; LD1 and LD2 are LEDs, indicating whether the secondary circuits of the I and II bus voltages are connected, respectively; 1YQJ4, 1YQJ5, and 1YQJ6 are control DC relays for switching to the secondary circuit of TV1 on the I section bus, 2YQJ4, 2Y... QJ5 and 2YQJ6 are control DC relays for switching to the secondary circuit of TV2 on the II-section busbar. Both are magnetically latched relays, meaning they will remain in the started state even if the DC power supply is lost after startup. R is the current-limiting resistor for the AC voltage disconnection circuit. 1YQJ4, 1YQJ5, 1YQJ6 and 2YQJ4, 2YQJ5, 2YQJ6 are all reverse-parallel diodes. Their function is to prevent the reverse electromotive force generated when the DC relay is disconnected from damaging components or causing any impact. The reverse-parallel diodes provide a path for the back electromotive force, thus providing protection. 1YQJ1, 1YQJ2, 1YQJ3 and 2YQJ1, 2YQJ2, 2YQJ3 are ordinary relays, mainly providing contacts for use in other circuits.

[0038] Figure 5 In the diagram, A630, B630, and C630 represent the three-phase voltage of the I busbar, L630 represents the zero-sequence voltage of the I busbar, A640, B630, and C640 represent the three-phase voltage of the II busbar, L640 represents the zero-sequence voltage of the II busbar, and A710, B710, C710, and L710 represent the voltages supplied to protection and control devices after the switching of the equipment. Figure 5 1YQJ4, 1YQJ5, 1YQJ6 and 2YQJ4, 2YQJ5, 2YQJ6 are Figure 4 The normally open contacts of the medium magnetic latching DC relays 1YQJ4, 1YQJ5, 1YQJ6 and 2YQJ4, 2YQJ5, 2YQJ6; 7D1 to 7D15 are all wiring terminals.

[0039] In this embodiment, a first indicator light is connected in the normally closed contact circuit of the I bus disconnect switch, and a second indicator light is connected in the normally closed contact circuit of the II bus disconnect switch.

[0040] The first indicator light is used to verify the correctness of the wiring in the secondary circuit where the normally closed auxiliary contact of the I bus disconnector is located when the secondary circuit corresponding to the I bus disconnector is rewired. The second indicator light is used to verify the correctness of the wiring in the secondary circuit where the normally closed auxiliary contact of the II bus disconnector is located when the secondary circuit corresponding to the II bus disconnector is rewired. This improves work efficiency. If the indicator light is not lit, the secondary circuit wiring can be checked, preventing wiring problems from causing voltage back to the de-energized bus when power is supplied, thus avoiding endangering personal and equipment safety.

[0041] Furthermore, the first indicator light is also used, during normal operation, in conjunction with the indicator light of the normally open contact start-up circuit of the I bus disconnector to indicate the actual position of the I bus disconnector. The second indicator light is also used, during normal operation, in conjunction with the indicator light of the normally open contact start-up circuit of the II bus disconnector to indicate the actual position of the II bus disconnector.

[0042] Optionally, the first indicator light is a light-emitting diode LD3, etc., and the second indicator light is a light-emitting diode LD4, etc.

[0043] Another embodiment of the present invention discloses a voltage switching control method with an indication of a blocking mode, applied to the voltage switching control device with an indication of a blocking mode in the above embodiment, comprising the following steps:

[0044] During normal operation, the first indicator light works in conjunction with the indicator light in the normally open contact start circuit of the I bus disconnect switch to indicate the actual position of the I bus disconnect switch;

[0045] When the secondary circuit corresponding to the I bus disconnect switch is rewired, the first indicator light can verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the I bus disconnect switch is located.

[0046] During normal operation, the second indicator light works in conjunction with the indicator light in the normally open contact start circuit of the II bus disconnect switch to indicate the actual position of the II bus disconnect switch;

[0047] When the secondary circuit corresponding to the II bus disconnect switch is rewired, the second indicator light can verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the II bus disconnect switch is located.

[0048] Reference Figure 5 The AC circuit includes a bus voltage circuit I and a bus voltage circuit II. In some embodiments, a relay 1JK is provided in the bus voltage circuit I, a normally closed contact of relay 1JK is provided in the bus voltage circuit II, a relay 2JK is provided in the bus voltage circuit II, and a normally closed contact of relay 2JK is provided in the bus voltage circuit I.

[0049] The relay 1JK is activated when the normally open auxiliary contact in the I bus voltage circuit is closed, and opens the normally closed contact 1JK in the II bus voltage circuit to cut off the corresponding voltage of the II bus; the relay 2JK is activated when the normally open auxiliary contact in the II bus voltage circuit is closed, and opens the normally closed contact 2JK in the I bus voltage circuit to cut off the corresponding voltage of the I bus.

[0050] The relay 1JK is installed on any phase of the I bus voltage circuit, and the relay 2JK is installed on any phase of the II bus voltage circuit. In the AC circuit of the dual bus voltage switching device, the corresponding contacts of the magnetically latching relays have the same function. Both the I and II bus voltage circuits can achieve voltage switching interlocking circuits using only one relay (the interlocking circuits are implemented by relay 1JK and relay 2JK respectively).

[0051] Among them, relay 1JK and relay 2JK can be installed on the same phase or on different phases. When the locking relay is connected to different contact circuits in the I bus and II bus voltage circuits, even if the contact used fails, the other contact circuit can still achieve the purpose of locking, thus improving reliability.

[0052] Another embodiment of the present invention discloses a voltage switching control method with an indication of a blocking mode, applied to the aforementioned voltage switching control device with an indication of a blocking mode, comprising the following steps:

[0053] When the normally open auxiliary contact in the I bus voltage circuit is closed, the relay 1JK is activated and opens the normally closed contact 1JK in the II bus voltage circuit to cut off the corresponding voltage of the II bus.

[0054] When the normally open auxiliary contact in the II bus voltage circuit is closed, the relay 2JK is activated and opens the normally closed contact 2JK in the I bus voltage circuit, cutting off the corresponding voltage of the I bus.

[0055] This invention adds an indicator light to the normally closed contact circuit of the isolating switch in the DC circuit of the dual bus voltage switching device. During normal operation, it can cooperate with the normally open contact start circuit of the isolating switch to indicate the actual position of the isolating switch. When the primary equipment of the isolating switch needs to be replaced or repaired, and the wiring of the corresponding secondary circuit changes or is rewired, the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the isolating switch is located can be checked in the main control room, thereby improving work efficiency.

[0056] This invention adds a blocking circuit to the AC circuit of the dual bus voltage switching device. During normal operation, even if the magnetic latching relay and its corresponding contacts malfunction, the added blocking circuit can ensure the singleness of the voltage circuit. When the disconnecting switch is replaced and the secondary circuit is rewired, even if the normally closed contact of the disconnecting switch is not wired correctly, the voltage of the energized bus will not return to the de-energized bus when power is supplied, thus improving intrinsic safety and ensuring the safety of personnel, power grid and equipment.

[0057] The present invention adds an indication and interlocking circuit to the dual bus voltage switching device, which can play a dual role in normal operation and rewiring when replacing equipment.

[0058] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A voltage switching control device with an indication and interlocking mode, comprising a DC circuit and an AC circuit, wherein the DC circuit includes a normally open contact starting circuit of a bus I disconnector, a normally closed contact circuit of a bus I disconnector, a normally open contact starting circuit of a bus II disconnector, and a normally closed contact circuit of a bus II disconnector, characterized in that, A first indicator light is connected in the normally closed contact circuit of the I bus disconnector, and a second indicator light is connected in the normally closed contact circuit of the II bus disconnector. The first indicator light is used to verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the I bus disconnector is located when the secondary circuit corresponding to the I bus disconnector is rewired; the second indicator light is used to verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the II bus disconnector is located when the secondary circuit corresponding to the II bus disconnector is rewired. The AC circuit includes a Bus I voltage circuit and a Bus II voltage circuit. A relay 1JK is installed in the Bus I voltage circuit, and a normally closed contact of 1JK is installed in the Bus II voltage circuit. A relay 2JK is installed in the Bus II voltage circuit, and a normally closed contact of 2JK is installed in the Bus I voltage circuit. The relay 1JK is activated when the corresponding normally open auxiliary contact in the Bus I voltage circuit is closed, and opens the normally closed contact of 1JK in the Bus II voltage circuit to cut off the corresponding voltage of Bus II. The relay 2JK is activated when the normally open auxiliary contact in the II bus voltage circuit is closed, and opens the normally closed contact 2JK in the I bus voltage circuit to cut off the corresponding voltage of the I bus.

2. The voltage switching control device with indicator lockout mode as described in claim 1, characterized in that, The first indicator light is also used to indicate the actual position of the I bus disconnect switch in normal operation, in conjunction with the indicator light of the normally open contact start circuit of the I bus disconnect switch.

3. The voltage switching control device with indicator lockout mode as described in claim 1, characterized in that, The second indicator light is also used to indicate the actual position of the II bus disconnector switch in normal operation, in conjunction with the indicator light of the normally open contact start circuit of the II bus disconnector switch.

4. The voltage switching control device with indicator lockout mode as described in claim 1, characterized in that, The first indicator light is a light-emitting diode.

5. The voltage switching control device with indicator lockout mode as described in claim 1, characterized in that, The second indicator light is a light-emitting diode.

6. The voltage switching control device with indicator lockout mode as described in claim 1, characterized in that, Relay 1JK and relay 2JK can be installed on the same phase or on different phases.

7. The voltage switching control device with indicated lockout mode as described in claim 1, characterized in that, The relay 1JK is installed on any phase of the I bus voltage circuit, and the relay 2JK is installed on any phase of the II bus voltage circuit.

8. A voltage switching control method with an indication lockout mode, applied to the voltage switching control device with an indication lockout mode as described in any one of claims 1-7, characterized in that, Includes the following steps: During normal operation, the first indicator light works in conjunction with the indicator light in the normally open contact start circuit of the I bus disconnect switch to indicate the actual position of the I bus disconnect switch; When the secondary circuit corresponding to the I bus disconnect switch is rewired, the first indicator light can verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the I bus disconnect switch is located. During normal operation, the second indicator light works in conjunction with the indicator light in the normally open contact start circuit of the II bus disconnect switch to indicate the actual position of the II bus disconnect switch; When the secondary circuit corresponding to the II bus disconnect switch is rewired, the second indicator light can verify the correctness of the wiring of the secondary circuit where the normally closed auxiliary contact of the II bus disconnect switch is located.

9. A voltage switching control method with an indication lockout mode, applied to the voltage switching control device with an indication lockout mode as described in any one of claims 1-7, characterized in that, Includes the following steps: When the normally open auxiliary contact in the I bus voltage circuit is closed, the relay 1JK is activated and opens the normally closed contact 1JK in the II bus voltage circuit to cut off the corresponding voltage of the II bus. When the normally open auxiliary contact in the II bus voltage circuit is closed, the relay 2JK is activated and opens the normally closed contact 2JK in the I bus voltage circuit, cutting off the corresponding voltage of the I bus.

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