Development of a Leakage Protector with Additional DC Source

Basic requirements of insulation resistance between isolated neutral power supply system of coal mine underground and ground were analyzed and principle and protection method of detecting insulation resistance by additional DC source were given. On the basis, a design scheme of software and hardware of leakage protector with additional DC source was introduced. The results of experiment and actual running showed that the leakage protector has small error and can meet requirement of leakage protection of underground power network.