Research of a separation method of positive and negative sequence component in coal mine power supply system

In view of problem that negative sequence components in unbalanced coal mine power system affect stable running of electric locomotive, and in order to satisfy control strategy of three-phase PWM rectifier, the characteristics of asymmetric signal under rotating coordinate system and the principle of enhanced notch filter were studied, and a separation method of positive and negative sequence component was presented. The rotating-coordinate system was used to transform the asymmetric signal and the enhanced adaptive notch filter was used to filter the two-times frequency signal in the method. The Matlab/Simulink simulation results show that the method can extract DC value of positive and negative sequence components in asymmetric signal precisely and quickly and can filter some harmonic waves.