CN201584316U - High voltage circuit breaker low voltage locking circuit - Google Patents

Abstract

The utility model discloses a locking circuit, which comprises a circuit breaker closing coil, a circuit breaker opening coil 1, and SF6 pressure relay contacts and relays connected in series between the positive and negative poles of the first operating power supply. The second contact of the SF6 pressure relay and the intermediate relay are connected in series between the positive and negative poles of the second operating power supply, and the intermediate relay node is connected in series in the opening coil 2 of the circuit breaker. The utility model enables the second node of the SF6 pressure relay of the circuit breaker and adds an intermediate relay. The second node of the SF6 pressure relay is connected in series in front of the intermediate relay to control whether the intermediate relay is excited; The node that plays the role of locking is changed so that the opening coil 2 of the circuit breaker is blocked when the SF6 pressure of the circuit breaker is lower than the locking value. In essence, the intermediate relay controls the opening and closing of the three opening circuits, thus avoiding possible open circuit Serious consequences such as device tripping, slow switching, and even explosion.

Description

High voltage circuit breaker low voltage locking circuit

Technical field:

The utility model relates to a circuit breaker of an electric power system, in particular to the transformation of a low-voltage blocking circuit of a high-voltage circuit breaker with two operating power sources.

Background technique:

Most of the ZF1-252(L)/2000-50 220kV high-voltage circuit breakers used in recent years have two operating power sources. As shown in Figure 1: Y1 is the closing coil of the circuit breaker, Y2 is the opening coil 1 of the circuit breaker, Y3 is the opening coil 2 of the circuit breaker, +KM1 is the positive pole of the first operating power supply, and -KM1 is the first operating power supply negative electrode. +KM2 is the positive pole of the second operating power supply, and -KM2 is the negative pole of the second operating power supply. The figure shows the normal pressure of SF6. The principle of the SF6 low pressure locking circuit is: when the SF6 pressure drops to the circuit breaker locking value, the first contact KD1-1 of the SF6 pressure relay is closed, the relay K10 is excited, and the normally closed contact of K10 is opened. , thus disconnecting the closing circuit, opening circuit 1, and opening circuit 2 of the circuit breaker, preventing the circuit breaker from slowly opening and closing. But precisely because of the loss of the first operating power supply, the relay K10 is not excited, the normally closed node of K10 is still closed, and the SF6 pressure locking contact K10 in the closing circuit, opening circuit 1 and opening circuit 2 of the circuit breaker fails, although the first circuit The operating power supply is lost, but the second operating power supply still exists, and the opening circuit 2 loses the SF6 low-voltage locking, which may cause circuit breaker tripping, slow opening, and even cause serious consequences such as circuit breaker explosion.

Utility model content:

The technical problem to be solved by this utility model is to provide a low-voltage locking circuit of a high-voltage circuit breaker for the above deficiencies, which leads to the second contact KD1-2 of the SF6 pressure relay, and adds another intermediate relay K11. The power used in this circuit is the first The second operating power supply has nothing to do with the first operating power supply, so even if the first operating power supply is lost, the opening circuit 2 can still be effectively blocked, avoiding the possible danger of tripping, slow opening or even explosion.

The technical scheme that the utility model takes is:

A low-voltage locking circuit of a high-voltage circuit breaker, including a circuit breaker closing coil, a circuit breaker opening coil 1, and SF6 pressure relay contacts and relays connected in series between the positive and negative poles of the first operating power supply, wherein : The second contact of the SF6 pressure relay and the intermediate relay are connected in series between the positive and negative poles of the second operating power supply, and the intermediate relay node is connected in series in the opening coil 2 of the circuit breaker.

The utility model enables the second node KD1-2 of the circuit breaker SF6 pressure relay, increases the intermediate relay K11, and the second node KD1-2 of the SF6 pressure relay is connected in series before the intermediate relay K11 to control whether the intermediate relay K11 is excited; the switch In the original design, the node K10, which acts as a blocking function for the opening coil 2 of the circuit breaker, is changed to K11, so that the opening coil 2 of the circuit breaker is blocked when the pressure of the SF6 of the circuit breaker is lower than the blocking value. In essence, the three points are controlled by the intermediate relay K11 The on-off of the gate circuit, thus avoiding possible serious consequences such as circuit breaker tripping, slow opening, and even explosion.

Description of drawings:

Figure 1 Schematic diagram of the original design of the ZF1-252(L)/2000-50 circuit breaker.

Fig. 2 is the structure schematic diagram of the utility model.

Detailed ways:

Below in conjunction with accompanying drawing, the utility model is further described:

As shown in Figure 1, if the first operating power supply of the circuit breaker is lost, even if the SF6 pressure drops at this time, the first contact KD1-1 of the SF6 pressure relay is closed, but because the first operating power supply is lost, the relay K10 is not excited, K10 The normally closed node is still closed, and the SF6 pressure locking contact K10 fails. Although the first operating power source is lost, the second operating power source still exists, and the circuit breaker opening coil loses the SF6 low-voltage locking, which may cause the circuit breaker to trip and slow down. It may even cause serious consequences such as circuit breaker explosion. Therefore, in order to avoid such accidents, the ZF1-252(L)/2000-50 circuit breaker has been modified, and the second KD1-2 of the SF6 pressure relay has been introduced, and another intermediate relay K11 has been added. The power supply is the second operating power supply, which has nothing to do with the first operating power supply, so even if the first operating power supply is lost, the circuit breaker coil 2 can still be effectively blocked, avoiding the above serious consequences.

Claims (1)

1. A low-voltage locking circuit of a high-voltage circuit breaker, including a circuit breaker closing coil, a circuit breaker opening coil 1, and SF6 pressure relay contacts and relays connected in series between the positive and negative poles of the first operating power supply , is characterized in that: the second contact point of the SF6 pressure relay and the intermediate relay are connected in series between the positive and negative poles of the two power sources, and the node of the intermediate relay is connected in series in the opening coil 2 of the circuit breaker.

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