Selection Design of Controller of Leakage Protector of Coal Mine

The paper analyzed influence of complicated underground circumstance on leakage protector of DC trolley system of coal mine and problem of bad reliability that using single-chip microcomputer as controller of leakage protector,and proposed a design scheme that using PLC with good stability to instead single-chip microcomputer as controller of leakage protector.The paper introduced circuit principle and software design of leakage protector based on S7-200 PLC and indicated leakage protector based on S7-200 PLC existed problem of slow executive procedure of PLC,and proposed a scheme that using KDN-K3 as controller of leakage protector.It made field test of rapidity and stability for the leakage protector based on KDN-K3 PLC.The test result showed that the leakage protector meets with requires of rapidity and stability.