Protection circuit, and switching device and power distribution system using same

The invention relates to a protection circuit operated in a solid-stage switch. The protection circuit is characterized by comprising a split-flow component connected to the output end of the solid-stage switch and a controllable switch; the split-flow component and the controllable switch are connected with each other; and the output end of the controllable switch is grounded. The protection circuit disclosed by the invention is operated in the solid-stage switch. When a load is in a working state, the controllable switch is disconnected. When the load is to be maintained or replaced, the solid-stage switch is disconnected at first; then the controllable switch is connected; the protection circuit is in a connection state; the split-flow component is used for discharging leakage current of the solid-stage switch to the ground; therefore, the protection circuit disclosed by the invention can be used for effectively preventing high voltage generated by the leakage current of the solid-stage switch from injurin