Research and development on mine flameproof and intrinsic safety AC frequency converter of mine scraper conveyor

Acording to low oveal ficiency of the scraper conveyor when in lght load operation and no load operation.low power factor of the power grd, an unbalanced power existed in the mut maotor driving .ifcutstarig with an insuficient staring torque mechanical impact and power grd surge existed in the staring perodand other problems the paper discussed the performance features of the scraper conveyor nd the special reqxuirements of the frecuency converer. The paper stated the compostion,working principle and main fechnical parameters of the fame proof and intrinsic sarety A C frequency converter apied in the scraper conwveyo. A research was conducted on the direct torque control overioad capacity soludion.energy saving operaion conro.power balanceofthe mut mor drving e ecrom agnetie imererences path and restrained measures of the frequency convertor,and other specal conrol fechnology;.The paper introduc.ed the ypicalalcaion condtions of the fame proof and intrinsic safety AC convertor applied in the scraper conveyor in the fuly mechanized topcoal caving mining face nXiming Mline Zhangcu Mine and other four underground mines.The application results showed that the equpment was reliable in the application .table in operation and enrgy saving and consumption redu:tion obvious and could meet the application requirements of the scraper with an 1 140 V power supply in the underground mine.