Direct-current power supply system of GIS control cubicle

Abstract

The utility model relates to a direct-current power supply system of a GIS control cubicle, and belongs to the field of GIS electrical equipment. The direct-current power supply system comprises a first direct-current power supply circuit and a second direct-current power supply circuit which supply power to a circuit breaker opening and closing control loop, the first direct-current power supply circuit and the second direct-current power supply circuit are connected with each other through a connection branch, and a connection switch is arranged on the connection branch in series; the interconnection switch is used for conducting the interconnection branch circuit when the first direct-current power supply circuit or the second direct-current power supply circuit cannot supply power normally and disconnecting the interconnection branch circuit when the first direct-current power supply circuit and the second direct-current power supply circuit can supply power normally. According to the direct-current power supply system, when any direct-current power supply breaks down suddenly, the other direct-current power supply can be used for maintaining normal operation of a circuit breaker opening and closing control loop, safe and stable operation of GIS equipment is guaranteed, and sufficient time can be reserved for operation and maintenance personnel to repair the fault power supply.

Description

Technical Field

[0001] The utility model belongs to the field of GIS electrical equipment, and particularly relates to a DC power supply system for a GIS control cubicle. Background Art

[0002] For GIS equipment with a voltage level of 220 kV and above, a control cubicle is provided for each interval. One of the functions of the control cubicle is to control the opening and closing of the circuit breaker, disconnector, and earthing switch in the interval. Among them, the opening and closing control circuit of the circuit breaker adopts a DC220V or DC110V DC power supply. Currently, users provide two independent DC power supplies for each control cubicle. The first DC power supply is used for the closing circuit of the circuit breaker and the first set of opening circuits, which can realize the remote control opening and closing, protection closing, and the first set of protection opening operations of the circuit breaker; the second DC power supply is used for the second set of opening circuits of the circuit breaker, which can realize the second set of protection opening operations of the circuit breaker; in the control cubicle, the first DC power supply and the second DC power supply have no direct connection.

[0003] The existing DC power supply system in the GIS control cubicle has the following defects: when the first DC power supply fails (loses voltage), the circuit breaker cannot perform remote control opening and closing and protection closing operations, and can only rely on the second set of opening circuits to complete the protection tripping operation. Therefore, the existing DC power supply system in the GIS control cubicle cannot ensure the safe and stable operation of the GIS equipment. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a DC power supply system for a GIS control cubicle to solve the problem that the existing DC power supply system in the GIS control cubicle cannot ensure the safe and stable operation of the GIS equipment.

[0005] The DC power supply system for a GIS control cubicle provided by the utility model to solve the above technical problems includes a first DC power supply circuit and a second DC power supply circuit for supplying power to the opening and closing control circuit of the circuit breaker. The first DC power supply circuit and the second DC power supply circuit are interconnected through a connection branch, and a connection switch is connected in series on the connection branch; the connection switch is used to conduct the connection branch when the first DC power supply circuit or the second DC power supply circuit cannot supply power normally, and disconnect the connection branch when both the first DC power supply circuit and the second DC power supply circuit can supply power normally.

[0006] Further, the connection switch is a DC contactor or a DC relay.

[0007] Further, there are two connection branches, namely the first connection branch and the second connection branch. Each connection branch interconnects the first DC power supply circuit and the second DC power supply circuit. A normally closed contact of a first connection switch is serially connected on the first connection branch, and a normally closed contact of a second connection switch is serially connected on the second connection branch. A control coil of the first connection switch is connected in parallel on the first DC power supply circuit, and a control coil of the second connection switch is connected in parallel on the second DC power supply circuit.

[0008] Further, a normally open contact of the first connection switch is serially connected on the first DC power supply circuit, and the normally open contact of the first connection switch is located between the connection point of the first connection branch and the first DC power supply circuit and the control coil of the first connection switch.

[0009] Further, a normally open contact of the second connection switch is serially connected on the second DC power supply circuit, and the normally open contact of the second connection switch is located between the connection point of the second connection branch and the second DC power supply circuit and the control coil of the second connection switch.

[0010] Further, the power supply system further includes a DC power supply fault alarm circuit, and the DC power supply fault alarm circuit is used to output an alarm signal when the connection switch is closed.

[0011] Further, the power supply system further includes a first DC power supply fault alarm circuit and a second DC power supply fault alarm circuit. A second normally closed contact of the first connection switch is serially connected in the first DC power supply fault alarm circuit, and a second normally closed contact of the second connection switch is serially connected in the second DC power supply fault alarm circuit.

[0012] Further, the breaker closing and opening control circuit includes a breaker closing control circuit, a first set of breaker opening control circuits, and a second set of breaker opening control circuits. The first DC power supply circuit is used to supply power to the breaker closing control circuit and the first set of breaker opening control circuits, and the second DC power supply circuit is used to supply power to the second set of breaker opening control circuits.

[0013] The beneficial effects of the present utility model are as follows: When both DC power supplies are normal, the power supply system of the present utility model can evenly distribute the load circuit on the two power supplies to achieve independent and balanced power supply; When any one of the DC power supplies suddenly fails, the other DC power supply can be used to maintain the normal operation of the breaker closing circuit, the first set of breaker opening circuits, and the second set of breaker opening circuits, ensuring the safe and stable operation of the GIS equipment, and leaving sufficient time for operation and maintenance personnel to repair the faulty power supply. Description of the Drawings

[0014] Figure 1This is the circuit schematic diagram of the DC power supply system for the GIS control cabinet in the embodiment of the present utility model. Detailed implementation manners

[0015] The following further describes the detailed implementation manners of the present utility model in conjunction with the accompanying drawings.

[0016] The basic idea of the present utility model is that the two DC power supplies in the DC power supply system of the GIS control cabinet are used as backups for each other. When any one of the DC power supplies fails (loses voltage), power switching can be performed so that the other normally operating DC power supply supplies power to the load corresponding to the faulty power supply, thereby ensuring the safe and stable operation of the GIS equipment.

[0017] Based on the above basic idea, the DC power supply system of the GIS control cabinet of the present utility model includes a first DC power supply circuit and a second DC power supply circuit for supplying power to the breaker closing and opening control circuits. The first DC power supply circuit and the second DC power supply circuit are interconnected through a connection branch, and a connection switch is serially provided on the connection branch; the connection switch is used to conduct the connection branch when the first DC power supply circuit or the second DC power supply circuit cannot supply power normally, and disconnect the connection branch when both the first DC power supply circuit and the second DC power supply circuit can supply power normally.

[0018] The breaker closing and opening control circuit of this embodiment includes a breaker closing control circuit, a first set of breaker opening control circuits, and a second set of breaker opening control circuits. The first DC power supply circuit is used to supply power to the breaker closing control circuit and the first set of breaker opening control circuits, and the second DC power supply circuit is used to supply power to the second set of breaker opening control circuits.

[0019] For the convenience of control, as a preferred implementation manner, the connection switch of this embodiment is a DC contactor or a DC relay. Preferably, the DC contactor is an electromagnetic contactor, and the DC relay is an electromagnetic relay. For the DC power supply system of GIS equipment with a voltage level of 220 kV and above, the rated coil voltage of the DC electromagnetic contactor and the DC electromagnetic relay is DC220V or DC110V.

[0020] As a preferred implementation manner, as Figure 1 shown, there are two connection branches in this embodiment, namely a first connection branch and a second connection branch. Each connection branch interconnects the first DC power supply circuit and the second DC power supply circuit; the first normally closed contact of the first connection switch KDC1 is serially provided on the first connection branch, and the first normally closed contact of the second connection switch KDC2 is serially provided on the second connection branch. The control coil of the first connection switch KDC1 is connected in parallel to the first DC power supply circuit, and the control coil of the second connection switch KDC2 is connected in parallel to the second DC power supply circuit.

[0021] Further, a normally open contact of a first connection switch KDC1 is serially arranged on the first DC power supply circuit, and the normally open contact of the first connection switch KDC1 is located between the connection point of the first connection branch and the first DC circuit power supply circuit and the control coil of the first connection switch KDC1.

[0022] Further, a normally open contact of a second connection switch KDC2 is serially arranged on the second DC power supply circuit, and the normally open contact of the second connection switch KDC2 is located between the connection point of the second connection branch and the second DC circuit power supply circuit and the control coil of the second connection switch KDC2.

[0023] In order to detect DC power supply faults in a timely manner and facilitate timely maintenance by maintenance personnel, a DC power supply fault warning circuit is also provided in the power supply system. The DC power supply fault warning circuit is used to output a warning signal when the connection switch is closed.

[0024] In order to facilitate timely knowledge of which DC power supply has a fault, as Figure 1 shown, the power supply system includes a first DC power supply fault warning circuit and a second DC power supply fault warning circuit. A second normally closed contact of the first connection switch KDC1 is serially arranged in the first DC power supply fault warning circuit, and a second normally closed contact of the second connection switch KDC2 is serially arranged in the second DC power supply fault warning circuit.

[0025] In this embodiment, a first DC air switch 8D1 is also serially arranged in the first DC power supply circuit. The first DC air switch 8D1 is in the closed state when the first DC power supply is working; a second DC air switch 8D2 is also serially arranged in the second DC power supply circuit. The second DC air switch 8D2 is in the closed state when the second DC power supply is working. The first DC air switch 8D1 and the second DC air switch 8D2 are selected as DC miniature circuit breakers.

[0026] Based on Figure 1 the GIS sub-control cabinet DC power supply system shown, the working principle of the GIS sub-control cabinet DC power supply system in this embodiment is described as follows.

[0027] 1) Normal operation condition.

[0028] Neither the first DC power supply nor the second DC power supply provided by the user has a fault (normal voltage), and the DC miniature circuit breakers 8D1 and 8D2 are both in the closed state.

[0029] The control coil of electromagnetic contactor KDC1 is energized, the first normally closed contacts 21-22 and 51-52 of electromagnetic contactor KDC1 are opened, disconnecting the first connection branch between the load "circuit breaker closing circuit, the first set of circuit breaker tripping circuits" and the second DC power supply; the normally open contacts 1-2 and 3-4 of electromagnetic contactor KDC1 are closed, and the first DC power supply supplies power to the load "circuit breaker closing circuit, the first set of circuit breaker tripping circuits".

[0030] The control coil of electromagnetic contactor KDC2 is energized, the first normally closed contacts 21-22 and 51-52 of electromagnetic contactor KDC2 are opened, disconnecting the second connection branch between the load "the second set of circuit breaker tripping circuits" and the first DC power supply; the normally open contacts 1-2 and 3-4 of electromagnetic contactor KDC2 are closed, and the second DC power supply supplies power to the load "the second set of circuit breaker tripping circuits".

[0031] Since both the first connection branch and the second connection branch are disconnected, in normal operation, the first DC power supply and the second DC power supply operate independently and supply power evenly to their respective load circuits.

[0032] 2) The operating conditions when the second DC power supply is normal and the first DC power supply suddenly fails (loses voltage) are as follows:

[0033] The DC miniature circuit breakers 8D1 and 8D2 are in the closed state, and the second DC power supply supplies power normally. At this time, the voltage of the first DC power supply disappears.

[0034] The control coil of electromagnetic contactor KDC1 loses power, the normally open contacts 1-2 and 3-4 of electromagnetic contactor KDC1 are opened, disconnecting the first DC power supply from the load "circuit breaker closing circuit, the first set of circuit breaker tripping circuits"; the first normally closed contacts 21-22 and 51-52 of electromagnetic contactor KDC1 are closed, conducting the first connection branch between the load "circuit breaker closing circuit, the first set of circuit breaker tripping circuits" and the second DC power supply, and the second DC power supply continues to supply power to the load "circuit breaker closing circuit, the first set of circuit breaker tripping circuits", and the "circuit breaker closing circuit, the first set of circuit breaker tripping circuits" can continue to operate normally.

[0035] At the same time, the second normally closed contact 61-62 of electromagnetic contactor KDC1 is closed, sending an alarm signal "the first DC power supply fails" to the substation monitoring background. After the user receives this signal, the DC miniature circuit breaker 8D1 can be disconnected first, and then the first faulty DC power supply can be repaired. After the faulty DC power supply is repaired, the DC miniature circuit breaker 8D1 is reclosed to restore to the normal operating state.

[0036] 3) The operating conditions when the first DC power supply is normal and the second DC power supply suddenly fails (loses voltage) are as follows:

[0037] The DC mini circuit breakers 8D1 and 8D2 are in the closed state, and the first DC power supply is supplying power normally. At this time, the voltage of the second DC power supply disappears.

[0038] The control coil of the electromagnetic contactor KDC2 loses power, and the normally open contacts 1-2 and 3-4 of the electromagnetic contactor KDC2 are disconnected, disconnecting the second DC power supply from the load "the second set of breaker tripping circuits"; the first normally closed contacts 21-22 and 51-52 of the electromagnetic contactor KDC2 are closed, conducting the second connection branch between the load "the second set of breaker tripping circuits" and the first DC power supply, and the first DC power supply continues to supply power to the load "the second set of breaker tripping circuits", and "the second set of breaker tripping circuits" can continue to operate normally.

[0039] At the same time, the second normally closed contact 61-62 of the electromagnetic contactor KDC2 is closed, sending an alarm signal "the second DC power supply fails" to the substation monitoring background. After the user receives this signal, the DC mini circuit breaker 8D2 can be disconnected first, and then the faulty second DC power supply can be repaired. After the faulty second DC power supply is repaired, the DC mini circuit breaker 8D2 is reclosed to restore to the normal operating state.

[0040] The DC power supply system of the GIS control cubicle of the present utility model can evenly distribute the load circuits on the two power supplies when both DC power supplies are normal, realizing independent and balanced power supply; when any one of the DC power supplies fails suddenly, it can maintain the normal operation of the breaker closing circuit, the first set of breaker tripping circuits, and the second set of breaker tripping circuits of the breaker, ensuring the safe and stable operation of the GIS equipment, and leaving sufficient time for operation and maintenance personnel to repair the faulty power supply.

Claims

1. A DC power supply system for a GIS control cabinet, the system comprising a first DC power supply circuit and a second DC power supply circuit for supplying power to the breaker closing and opening control circuits, characterized in that, The first DC power supply circuit and the second DC power supply circuit are interconnected through a connection branch, and a connection switch is serially arranged on the connection branch; the connection switch is used to conduct the connection branch when the first DC power supply circuit or the second DC power supply circuit cannot supply power normally, and disconnect the connection branch when both the first DC power supply circuit and the second DC power supply circuit can supply power normally.

2. The DC power supply system of the GIS control cubicle according to claim 1, wherein The connection switch is a DC contactor or a DC relay.

3. The DC power supply system of the GIS control cabinet according to claim 2, characterized in that, There are two connection branches, namely the first connection branch and the second connection branch. Each connection branch interconnects the first DC power supply circuit and the second DC power supply circuit; the normally closed contact of the first connection switch is serially arranged on the first connection branch, the normally closed contact of the second connection switch is serially arranged on the second connection branch, the control coil of the first connection switch is connected in parallel on the first DC power supply circuit, and the control coil of the second connection switch is connected in parallel on the second DC power supply circuit.

4. The DC power supply system of the GIS control cabinet according to claim 3, characterized in that, The normally open contact of the first connection switch is serially arranged on the first DC power supply circuit, and the normally open contact of the first connection switch is located between the connection point of the first connection branch and the first DC power supply circuit and the control coil of the first connection switch.

5. The DC power supply system of the GIS control cubicle according to claim 3, wherein, The normally open contact of the second connection switch is serially arranged on the second DC power supply circuit, and the normally open contact of the second connection switch is located between the connection point of the second connection branch and the second DC power supply circuit and the control coil of the second connection switch.

6. The DC power supply system of the GIS control cabinet according to claim 1, wherein, This power supply system further includes a DC power supply fault alarm circuit, and the DC power supply fault alarm circuit is used to output an alarm signal when the connection switch is closed.

7. The DC power supply system of the GIS control cubicle according to claim 3, wherein This power supply system further includes a first DC power supply fault alarm circuit and a second DC power supply fault alarm circuit. The second normally closed contact of the first connection switch is serially arranged in the first DC power supply fault alarm circuit, and the second normally closed contact of the second connection switch is serially arranged in the second DC power supply fault alarm circuit.

8. The DC power supply system of the GIS control cabinet according to any one of claims 1 to 7, characterized in that The breaker closing and opening control circuit includes a breaker closing control circuit, a first set of breaker opening control circuits, and a second set of breaker opening control circuits. The first DC power supply circuit is used to supply power to the breaker closing control circuit and the first set of breaker opening control circuits, and the second DC power supply circuit is used to supply power to the second set of breaker opening control circuits.

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