The distribution network using the small resistance grounding method has a high resistance dead zone

which has certain impact on personal safety

power supply reliability

and grid security. In order to solve the problem of small resistance grounding method

an intelligent resistance grounding method based on single-phase grounding fault zone is proposed. The method divides the faults according to the grid neutral point displacement voltage and fault line current change. In the high resistance fault zone

the double incremental start-up is adopted

and the fault lines are fast selected to remove faults. In the medium and low resistance fault zones

different delay processing methods are adopted to recover transient faults

improving the power supply reliability of distribution network and the personal safety and the power grid security. The developed device has been proved by experiment. It has a high resistance recognition processing capability of 5 000 Ω

which can recover the temporary fault of current amplitude of 65 A

and can accurately judge and remove the permanent fault. Compared with the small resistance grounding method

the intelligent resistance grounding method can effectively improve personal safety

grid security and power supply reliability.