The arc protection system is generally composed of the main control unit, arc collector and arc sensor. The arc light sensor is used to detect the arc light, and then the circuit breaker trip signal is output through the high-speed solid-state outlet. According to the rapid response of the system to the arc light, the fastest time from detecting the arc light to sending out the trip signal should be within 7 Ms.

In the process of substation operation, safety and stability are important factors. In recent years, in the construction of substation, due to the characteristics of small floor area, centralized operation, convenient operation and maintenance, a large number of medium and low voltage switch cabinets are configured in the substation. In the process of operation, there are more and more serious burning accidents of switchgear due to various reasons. Improper handling of substation accidents will directly affect the safety and stability of substation operation, and lead to the expansion of power grid accidents, which will not only bring serious economic losses, but also cause casualties.

In the process of substation design, in order to ensure the safe operation of transformer, bus and switch equipment, protection devices are configured according to relevant specifications. However, at present, the domestic bus bar of 35kV and below is generally not equipped with special fast bus protection, but the backup over-current protection of transformer is used to cut off the bus fault, which increases the damage to the equipment. Therefore, in the substation low-voltage switch cabinet equipped with arc protection device, once the fault occurs, the fault can be removed in time to prevent further expansion of the fault.

The advantages of special bus arc protection system are as follows:

1. It can protect the workers nearby from the harm caused by electric arc light;

2. It can protect the medium and low voltage equipment from serious damage in a large range, and put an end to the occurrence of fire;

3. It can effectively protect the main transformer and avoid the impact damage of auxiliary transformer;

4. Prevent the DC system from spreading to the station, and effectively reduce the economic loss;

5. Effectively reduce the power outage time of users, and avoid great impact on the production and life of power supply residents;

6. Reduce the damage to equipment and lines, and extend the service life of each equipment.