The Auto Reclosing Circuit Breaker is an automatic device which automatically puts in the circuit breaker after the break-off due to the fault. The operation experience of power system shows that most of the faults of overhead lines are transient permanent faults, generally less than 10%. Therefore, after the short-circuit fault is removed by relay protection action. The arc will be extinguished automatically. In most cases, the insulation at the short circuit can be restored automatically. Therefore, the automatic overlap of circuit breakers not only improves the safety and reliability of power supply, reduces the loss of power outage, but also improves the transient stability level of power system, increases the capacitance of high voltage lines, and can also be corrected. Because of the wrong tripping caused by circuit breaker and relay protection device, the overhead line should adopt Auto Reclosing Circuit Breaker.

With the rapid development of industry, PV Auto Reclosing is also widely used. Today, we will talk about the importance of automatic reclosure leakage protector.

In a thunderstorm in various regions, many equipments were damaged by lightning, many outdoor equipments'lightning protection actions, many leakage protection switches tripped, many outdoor important equipments stopped working and waited for the arrival of maintenance personnel. This common transient fault seriously affected the stability of network equipment and company reputation, resulting in. Network waste and economic loss. It is very necessary to automatically overlap with its own low failure rate and fault identification (permanent and transient faults).

It is well known that the pre-reclosure acceleration protection is generally used in radiation lines with several sections in series, and the reclosing device is only installed on a section of line close to the power supply. Well, we all know what features and advantages and disadvantages of PV Auto Reclosing. Today, let's know about it.

Advantage:
1) It can ensure continuous power supply to users in most cases of faults, so as to improve the reliability of power supply; when one-side power supply and one-loop power supply to important loads, it has more significant advantages to ensure uninterrupted power supply.
2) Using single-phase Auto Reclosing Circuit Breaker on the connection line of bilateral power supply can greatly strengthen the connection between the two systems in case of failure, so as to improve the dynamic stability of parallel operation of the system. For systems with weak connections, when three-phase resection and three-phase reclosure are difficult to restore synchronization, single-phase reclosure can avoid the separation of the two systems.

Shortcomings:
1) The circuit breaker with phase operation is required.
2) It needs special phase selector to cooperate with relay protection, and after considering some special requirements, the connection of PV Auto Reclosing is more complex.
3) In the process of single-phase reclosure, because the non-full-phase operation can cause the protection malfunction of the line and other lines in the power grid, measures should be taken to prevent it according to the actual situation, which will complicate the wiring, setting calculation and debugging of the protection.