Arc protection system has the characteristics of simple principle, simple structure, fast and reliable action, fault location, circuit breaker failure protection and so on. Improving the fault processing speed can effectively solve the harm caused by short circuit fault arc, reduce equipment maintenance and casualties, and improve the safety and economic benefits of power system.

During the maintenance of a 220kV substation of a power supply bureau in Henan Province, the internal fault of the incoming cabinet in the distribution room exploded, and six workers nearby were burned. A transformer outside the distribution room was burned due to a short circuit, and the substation was cut off. The accident caused a large-scale power outage in some areas of the city for one hour.

The key to solve the problem is to cut off the power supply and extinguish the arc as soon as possible. The arc light protection device can achieve this. The arc light protection system has two criterions: arc light criterion and current criterion. On the one hand, it can prevent the power failure caused by daily light irradiation, on the other hand, it can also prevent the current rise caused by other faults, which will lead to the action of arc protection device and affect the normal operation. When only one of them is detected, it will send out an alarm signal. Arc can quickly detect the occurrence of arc, and the whole action will trip out quickly, so the protection action is reliable.