With the development of social economy

the power system has become increasingly complex

the switchgear cabinet

as one of the important equipment to maintain stable operation of the power system

also plays an increasingly important role

and attention shall be paid to the the safe protection of the arc fault of the switchgear cabinet. In order to achieve effective protection against the arc fault of the switchgear cabinet

the causes and harm due to the arc fault inside the switchgear cabinet are introduced firstly in this paper. Then

the existing methods for dealing with the arc fault of the switchgear cabinet is compared

the insufficiency of the pressure relief channel method of the switchgear cabinet and of the fault diagnosis information transmitted to the host circuit breaker is analyzed

and a method of using fault arc detection and rapid earthing switch to protect the switchgear cabinet and prevent major accidents in the switchgear cabinet is obtained. By comparing the existing fault detection methods and the two driving modes of the operating mechanism for the fast earthing switch

the scheme of combining the arc overcurrent protection criterion and the electromagnetic repulsion mechanism is introduced

which can realize the effective protection of the internal arc fault of the switchgear cabinet.