Abstract: In view of the problems of limited installation space, relatively poor on-site environment, inconvenient transportation and installation of frequency converters and others for the main haulage belt conveyor head of Yanmei Wanfu Energy Co., Ltd., the mine used general type frequency converter is used to replace the flame-proof type frequency converter. The frequency converter is installed in the downhole −820 central substation, providing a well ventilated, suitable temperature, relatively low dust, dry, and spacious operating environment for the frequency converter, decreasing the equipment failure rate and reducing the maintenance quantity. At the same time, a 10 kV high-voltage long distance power supply way is adopted, and the unit cascade sine pulse width carrier wave phase shifting technology is used to solve the problems of large change rate of system voltage, high content of harmonic and so on, improving the safety usage performance of the motor.