To limit high-level short-circuit current in EHV power grid

a novel passive fault current limiter based on high reliability controllable multi-stage spark gap was developed. Compared with the existing EHV grid fault current limiter

this fault current limiter is higher in reliability and reaction speed

and lower in the costs for manufacture

operation and maintenance. And the design concept and working principle of this device are introduced.Experiment of operation reliability and actuation time on a prototype indicates that reliable actuation of this device can be achieved within 25 microsecond. Furthermore

the control strategy is designed

and the effects of time-series and current limitation of the system is analyzed.