In the power system, more than one electrical engineer or electrician is injured by electric arc every year. Nowadays, the safety of electric power is highly valued. How to better ensure personal safety and ensure the stable and reliable operation of power supply system is very important. The arc protection device can quickly remove the fault point to ensure the safe and stable operation of the system.

In recent years, due to various reasons, the switch equipment has been severely burned. Every year, 7 sets of switch cabinets are damaged, with the failure rate of 0.7%. The probability of rural distribution network is higher, reaching 1.2%. Some of them will even become "fire and fire" accidents. These distribution network accidents are improperly handled and even expanded into transmission network accidents, causing significant economic losses, which have aroused widespread concern of the power sector.

When the medium and low voltage bus short circuit fault occurs, the arc light generated will cause great harm to equipment and personnel. It is concluded that most of the accidents are caused by the lack of arc protection device and the failure to quickly remove the fault. The bus short-circuit fault is removed by relying on the backup protection of the upper transformer, which leads to the extension of the fault removal time and increases the damage degree of the equipment. When the damage is serious, the accident may be further expanded, threatening the stable operation of the system.

In order to ensure the safe operation of transformer and bus switch equipment, special arc protection device is urgently needed. From the practical application, the existing protection methods obviously can not meet the requirements of rapid removal of bus fault or protection coverage. Therefore, it is necessary and urgent to install a fast arc protection device in medium and low voltage bus and switch cabinet.