A mother difference protection jump access circuit

Abstract

The application relates to a bus differential protection jump access circuit, which comprises a control power supply, a protection power supply, a remote / local conversion switch, a remote / local auxiliary relay, a closing coil, a bus tie breaker and a local closing auxiliary relay, wherein one end of a normally closed contact point of the remote / local conversion switch is connected with a positive pole PG of the control power supply, the other end of the normally closed contact point of the remote / local conversion switch is connected with a negative pole NG of the control power supply after being connected with a coil of the remote / local auxiliary relay in series, the other end of three groups of normally closed auxiliary contact points of the bus tie breaker connected in series is connected with an incoming terminal of a bus differential protection circuit, and a connecting terminal on the other side of the bus differential protection circuit is connected with a negative pole connecting end-KM of the protection power supply. The application solves the problem that the bus differential protection bus tie jump is controlled by the remote / local conversion switch, effectively solves the problem that the bus differential protection misissues an abnormal signal alarm, and provides favorable conditions for safe and reliable operation of a power supply system.

Description

Technical Field

[0001] This invention relates to the field of power supply equipment technology, specifically a bus differential protection trip connection circuit. Background Technology

[0002] In modern power supply systems, the bus tie tripping points of the bus differential protection all use the normally open contacts of the tripping relay TWJ inside the bus tie microcomputer integrated protection device. The normally open contacts of this tripping relay TWJ are controlled by the remote / local transfer switch. When the remote / local transfer switch is switched to local, the coil power supply circuit of the tripping relay TWJ in the bus tie protection device will be cut off, which will cause the normally open contacts of the tripping relay TWJ to open. As a result, the bus differential protection circuit will not receive feedback from the bus tie tripping, which will cause the bus differential protection circuit to issue an abnormal signal alarm. In other words, false alarms will occur due to the remote / local transfer switch switching to local. Therefore, it cannot correctly reflect the normal operating status of the bus differential protection and affects the safe operation of the power supply system.

[0003] Therefore, how to design the tripping access circuit in the new bus differential protection circuit is the technical problem that this application aims to solve. Summary of the Invention

[0004] The purpose of this invention is to provide a bus differential protection tripping access circuit, which solves the problem of false alarms caused by abnormal signals in the bus differential protection circuit, improves the stability of the bus differential protection, and ensures the safe and reliable operation of the power supply system.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a bus differential protection trip connection circuit, including a control power supply, a protection power supply, a remote / local transfer switch, a remote / local auxiliary relay, a closing coil, a bus tie circuit breaker, and a local closing auxiliary relay, wherein: One end of the normally closed contact of the remote / local transfer switch is connected to the positive terminal PG of the control power supply, and the other end of the normally closed contact of the remote / local transfer switch is connected to the negative terminal NG of the control power supply after being connected in series with the coil of the remote / local auxiliary relay. The remote / local auxiliary relay has at least three sets of contacts, including a first normally open contact, a second normally open contact, and a third normally closed contact; the bus tie circuit breaker has at least two sets of normally closed auxiliary contacts, wherein: One end of the first normally open contact is connected to at least one set of normally closed auxiliary contacts of the bus tie circuit breaker and one end of the protection closing circuit breaker. At least one set of normally closed auxiliary contacts of the bus tie circuit breaker are connected in series. One end of at least one set of normally closed auxiliary contacts of the bus tie circuit breaker and the other end of the protection closing circuit breaker are connected to the positive terminal +KM of the protection power supply. The other end of the first normally open contact is connected in series with another set of normally closed auxiliary contacts of the bus tie circuit breaker and the closing coil, and then connected to the negative terminal NG of the control power supply. One end of the second normally open contact is connected to one end of the remote operation closing of the remote / local transfer switch, and the other end of the remote operation closing is connected to the positive terminal +KM of the protection power supply. The other end of the second normally open contact is connected in series with another set of normally closed auxiliary contacts of the bus tie circuit breaker and the closing coil, and then connected to the negative terminal NG of the control power supply. One end of the third normally closed contact is connected to one end of the local operation closing of the remote / local transfer switch, and the other end of the local operation closing is connected to the positive terminal PG of the control power supply. The other end of the third normally closed contact is connected in series with the coil of the local closing auxiliary relay and then connected to the negative terminal of the control power supply. One end of the normally open contact of the local closing auxiliary relay is connected to the positive terminal PG of the control power supply, and the other end of the normally open contact of the local closing auxiliary relay is connected to the other end of the first normally open contact. The other end of at least one set of normally closed auxiliary contacts of the bus tie circuit breaker is connected to the input terminal of the bus differential protection circuit, and the connection terminal on the other side of the bus differential protection circuit is then connected to the negative terminal-KM of the protection power supply.

[0006] The applicant has further optimization measures for the above technical solution.

[0007] Optionally, the bus tie circuit breaker is a 220kV voltage level bus tie phase circuit breaker.

[0008] Optionally, the bus tie circuit breaker includes a first normally closed auxiliary contact, one end of which is connected to the other end of the first normally open contact, and the other end of which is connected in series with the closing coil and then connected to the negative terminal NG of the control power supply.

[0009] Optionally, the bus tie circuit breaker further includes an A-phase normally closed auxiliary contact, a B-phase normally closed auxiliary contact, and a C-phase normally closed auxiliary contact. One end of the A-phase normally closed auxiliary contact is connected to the positive terminal +KM of the protection power supply. The other end of the A-phase normally closed auxiliary contact is connected to one end of the B-phase normally closed auxiliary contact. The other end of the B-phase normally closed auxiliary contact is connected to one end of the C-phase normally closed auxiliary contact. The other end of the C-phase normally closed auxiliary contact is connected to the input terminal of the bus differential protection circuit.

[0010] Furthermore, when the first normally open contact of the remote / local auxiliary relay is in the open state, the remote protection closing circuit is disconnected.

[0011] Furthermore, when the second normally open contact of the remote / local auxiliary relay is in the open state, the remote operation closing circuit is disconnected.

[0012] Furthermore, when the third normally closed contact of the remote / local auxiliary relay is in the on state, the local closing auxiliary relay is energized, and the normally open contact of the local closing auxiliary relay closes and conducts, connecting the local operation closing circuit.

[0013] Compared with the prior art, the advantages of this invention patent application are as follows: The bus differential protection trip access circuit of this application uses the three-phase normally closed auxiliary contacts of the bus coupler phase circuit breaker connected to the input terminal of the bus differential protection circuit, which improves the bus coupler trip access circuit in the bus differential protection circuit. This solves the problem that the bus coupler trip of the bus differential protection is controlled by the remote / local transfer switch, and solves the problem that the traditional bus coupler trip relay TWJ does not correspond to the actual position. In addition, it effectively solves the problem of false abnormal signal alarms of the bus differential protection, and provides favorable conditions for the safe and reliable operation of the power supply system. Attached Figure Description

[0014] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of the overall wiring of the bus differential protection trip connection circuit according to an embodiment of the present invention; Figure 2 This is a wiring diagram of the bus tie circuit breaker tripping connection to the bus differential protection circuit according to an embodiment of the present invention.

[0015] The annotations in the attached figures are explained as follows: PG, NG: Control power supply; 43RL: Remote / Local Switch; M1: Remote / local auxiliary relay; DL1~DL4: Normally closed auxiliary contacts of the bus tie circuit breaker; HQ: Closing coil; CX: Local closing auxiliary relay; TWJ: Jumper relay. Implementation

[0016] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0019] This embodiment describes a bus differential protection tripping access circuit, such as Figure 1 As shown, it includes a control power supply, a protection power supply, a remote / local transfer switch 43RL, a remote / local auxiliary relay M1, a closing coil HQ, a bus tie circuit breaker, and a local closing auxiliary relay CX. In addition, the energization status of the trip relay TWJ is also described in this embodiment.

[0020] Specifically: one end of the normally closed contact of the remote / local transfer switch 43RL is connected to the positive terminal PG of the control power supply, and the other end of the normally closed contact of the remote / local transfer switch 43RL is connected to the negative terminal NG of the control power supply after being connected in series with the coil of the remote / local auxiliary relay M1, wherein the supply voltage of the control power supply is DC 220V. When the remote / local switch 43RL is switched to "remote", the normally closed contact (1-2) of the remote / local switch 43RL closes, the coil of the remote / local auxiliary relay M1 is energized, the first normally open contact (5-6) and the second normally open contact (3-4) of the remote / local auxiliary relay M1 close, controlling the connection of the remote closing circuit, and the third normally closed contact (7-8) opens, controlling the disconnection of the circuit breaker's local closing circuit; when the remote / local switch 43RL is switched to "local", the normally closed contact (1-2) of the remote / local switch 43RL opens, the coil of the remote / local auxiliary relay M1 is de-energized, the first normally open contact (5-6) and the second normally open contact (3-4) of the remote / local auxiliary relay M1 open, controlling the disconnection of the remote closing circuit, and the third normally closed contact (7-8) conducts, controlling the connection of the circuit breaker's local closing circuit.

[0021] In this embodiment, the remote / local auxiliary relay M1 has three sets of contacts, including a first normally open contact (5-6), a second normally open contact (3-4), and a third normally closed contact (7-8). The bus tie circuit breaker has at least two sets of normally closed auxiliary contacts, wherein: One end of the first normally open contact (5-6) of the remote / local auxiliary relay M1 is connected to one end of the trip relay TWJ and one end of the protection closing circuit. The other end of the trip relay TWJ is connected to the other end of the protection closing circuit. At least one set of normally closed auxiliary contacts of the bus tie circuit breaker are connected in series. One end of the at least one set of normally closed auxiliary contacts connected in series in the bus tie circuit breaker and the other end of the protection closing circuit are connected to the positive terminal +KM of the protection power supply. The other end of the first normally open contact (5-6) is connected in series with another set of normally closed auxiliary contacts of the bus tie circuit breaker and the closing coil HQ, and then connected to the negative terminal NG of the control power supply. When the first normally open contact (5-6) of the remote / local auxiliary relay M1 is in the open state, the remote protection closing circuit is disconnected. One end of the second normally open contact (3-4) of the remote / local auxiliary relay M1 is connected to one end of the remote operation closing terminal of the remote / local transfer switch 43RL. The other end of the remote operation closing terminal is connected to the positive terminal +KM of the protection power supply. The other end of the second normally open contact (3-4) is connected in series with another set of normally closed auxiliary contacts of the bus tie circuit breaker and the closing coil HQ, and then connected to the negative terminal NG of the control power supply. When the second normally open contact (3-4) is in the open state, the remote operation closing circuit is disconnected. One end of the third normally closed contact (7-8) of the remote / local auxiliary relay M1 is connected to one end of the local operation closing of the remote / local changeover switch 43RL. The other end of the local operation closing is connected to the positive terminal PG of the control power supply. The other end of the third normally closed contact (7-8) is connected in series with the coil of the local closing auxiliary relay CX and then connected to the negative terminal of the control power supply. One end of the normally open contact (9-10) of the local closing auxiliary relay CX is connected to the positive terminal PG of the control power supply. The other end of the normally open contact (9-10) of the local closing auxiliary relay CX is connected to the other end of the first normally open contact (5-6). When the third normally closed contact (7-8) is in the closed state, the local closing auxiliary relay CX is energized, and the normally open contact (9-10) of the local closing auxiliary relay CX closes and conducts, connecting the local operation closing circuit.

[0022] The other end of at least one set of normally closed auxiliary contacts of the bus tie circuit breaker is connected to the input terminal of the bus differential protection circuit, and the connection terminal on the other side of the bus differential protection circuit is then connected to the negative terminal-KM of the protection power supply.

[0023] In one implementation, such as Figure 1 As shown, the bus tie circuit breaker includes a first normally closed auxiliary contact DL1. One end of the first normally closed auxiliary contact DL1 is connected to the other end of the first normally open contact (5-6). The other end of the first normally closed auxiliary contact DL1 is connected in series with the closing coil HQ and then connected to the negative terminal NG of the control power supply.

[0024] In another further embodiment, the bus tie circuit breaker is a 220kV voltage level bus tie phase circuit breaker. For example... Figure 2 As shown, the bus tie circuit breaker also includes a normally closed auxiliary contact DL2 for phase A, a normally closed auxiliary contact DL3 for phase B, and a normally closed auxiliary contact DL4 for phase C. One end of the normally closed auxiliary contact DL2 for phase A is connected to the positive terminal +KM of the protective power supply. The other end of the normally closed auxiliary contact DL2 for phase A is connected to one end of the normally closed auxiliary contact DL3 for phase B. The other end of the normally closed auxiliary contact DL3 for phase B is connected to one end of the normally closed auxiliary contact DL4 for phase C. The normally closed auxiliary contact DL4 for phase C... The other end is connected to the input terminal 2-1n6×8 of the bus differential protection circuit. After passing through the internal bus differential protection circuit, it is connected to the negative terminal-KM of the protection power supply via the connection terminal 2-1n6×18. When all three phase circuit breakers of the bus tie circuit breaker in the circuit are in the open position, the three sets of auxiliary contacts DL2 (phase A), DL3 (phase B), and DL4 (phase C) are all closed, connecting the bus tie trip circuit in the bus differential protection and completing the bus differential protection trip access circuit.

[0025] In summary, the bus differential protection trip access circuit of this application uses the three-phase normally closed auxiliary contacts of the bus coupler phase circuit breaker connected to the input terminal of the bus differential protection circuit, which improves the bus coupler trip access circuit in the bus differential protection circuit. This solves the problem that the bus coupler trip of the bus differential protection is controlled by the remote / local changeover switch 43RL, and solves the problem that the traditional bus coupler trip relay TWJ does not correspond to the actual position. In addition, it effectively solves the problem of false alarm of abnormal signals by the bus differential protection, and provides favorable conditions for the safe and reliable operation of the power supply system.

[0026] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A bus differential protection tripping circuit, characterized in that, This includes control power supply, protection power supply, remote / local transfer switch, remote / local auxiliary relay, closing coil, bus tie circuit breaker, and local closing auxiliary relay, among which: One end of the normally closed contact of the remote / local transfer switch is connected to the positive terminal PG of the control power supply, and the other end of the normally closed contact of the remote / local transfer switch is connected to the negative terminal NG of the control power supply after being connected in series with the coil of the remote / local auxiliary relay. The remote / local auxiliary relay has at least three sets of contacts, including a first normally open contact, a second normally open contact, and a third normally closed contact. The bus tie circuit breaker has at least two sets of normally closed auxiliary contacts, wherein: One end of the first normally open contact is connected to one end of the trip relay and one end of the protection closing circuit. At least one set of normally closed auxiliary contacts of the bus tie circuit breaker are connected in series. One end of at least one set of normally closed auxiliary contacts of the bus tie circuit breaker and the other end of the protection closing circuit are connected to the positive terminal +KM of the protection power supply. The other end of the first normally open contact is connected in series with another set of normally closed auxiliary contacts of the bus tie circuit breaker and the closing coil, and then connected to the negative terminal NG of the control power supply. One end of the second normally open contact is connected to one end of the remote operation closing of the remote / local transfer switch, and the other end of the remote operation closing is connected to the positive terminal +KM of the protection power supply. The other end of the second normally open contact is connected in series with another set of normally closed auxiliary contacts of the bus tie circuit breaker and the closing coil, and then connected to the negative terminal NG of the control power supply. One end of the third normally closed contact is connected to one end of the local operation closing of the remote / local transfer switch, and the other end of the local operation closing is connected to the positive terminal PG of the control power supply. The other end of the third normally closed contact is connected in series with the coil of the local closing auxiliary relay and then connected to the negative terminal of the control power supply. One end of the normally open contact of the local closing auxiliary relay is connected to the positive terminal PG of the control power supply, and the other end of the normally open contact of the local closing auxiliary relay is connected to the other end of the first normally open contact. The other end of at least one set of normally closed auxiliary contacts of the bus tie circuit breaker is connected to the input terminal of the bus differential protection circuit. The connection terminal on the other side of the bus differential protection circuit is then connected to the negative connection terminal -KM of the protection power supply. The bus tie circuit breaker also includes an A-phase normally closed auxiliary contact, a B-phase normally closed auxiliary contact, and a C-phase normally closed auxiliary contact. One end of the A-phase normally closed auxiliary contact is connected to the positive connection terminal +KM of the protection power supply. The other end of the A-phase normally closed auxiliary contact is connected to one end of the B-phase normally closed auxiliary contact. The other end of the B-phase normally closed auxiliary contact is connected to one end of the C-phase normally closed auxiliary contact. The other end of the C-phase normally closed auxiliary contact is connected to the input terminal of the bus differential protection circuit.

2. The bus differential protection trip connection circuit according to claim 1, characterized in that, The bus tie circuit breaker is a 220kV voltage level phase-by-phase circuit breaker.

3. The bus differential protection trip connection circuit according to claim 2, characterized in that, The bus tie circuit breaker includes a first normally closed auxiliary contact. One end of the first normally closed auxiliary contact is connected to the other end of the first normally open contact. The other end of the first normally closed auxiliary contact is connected in series with the closing coil and then connected to the negative terminal NG of the control power supply.

4. The bus differential protection trip connection circuit according to any one of claims 1 to 3, characterized in that, When the first normally open contact of the remote / local auxiliary relay is in the open state, the remote protection closing circuit is disconnected.

5. The bus differential protection trip connection circuit according to any one of claims 1 to 3, characterized in that, When the second normally open contact of the remote / local auxiliary relay is in the open state, the remote operation closing circuit is disconnected.

6. The bus differential protection trip connection circuit according to any one of claims 1 to 3, characterized in that, When the third normally closed contact of the remote / local auxiliary relay is in the ON state, the local closing auxiliary relay is energized, and the normally open contact of the local closing auxiliary relay closes to conduct, thus connecting the local operation closing circuit.

Images