Design of Mine-used Protection Device for Override Trip

The paper analyzed causes of override trip of underground power supply lines based on characteristics of multi levels and short lines of power supply lines of coal mine underground, designed a reverse locking type longitudinal protection device for override trip with 32-bit TMS320F2812 DSP as main processor. The test results showed that the protection device can solve the problem of override trip of underground power supply lines, and improve reliability of underground power system.