Hybrid filter topology to minimize harmonics and EMI noise in PMSM with HDTC

In this paper, a hybrid filter topology is proposed to minimize voltage harmonics, current harmonics and EMI noises in PMSM with hysteresis direct torque control (HDTC). The filter topology consists of IGBT active filter (AF), high frequency LC filter and trap filter. The coupling of the AF compensated voltage and the motor main voltage is achieved through series 1:1 transformer. The AF detects the harmonics in the motor phase voltages and uses hysteresis band control method to provide almost sinusoidal voltage to the motor windings. The simulation results of the proposed hybrid filter show considerable voltage and current ripples reduction in steady state range as well as considerable total harmonics and EMI noise reduction.