A CL-LC filter for high-power PWM current-source drive systems

Due to the effective attenuation on switching-frequency harmonics with a smaller size of passive components, the high-order filters using LC trap branch are recently emerging into grid-tied voltage-source inverter (VSI) systems. Based on the idea of LC trap branch, a new-type CL-LC line-side filter is proposed for high-power PWM current-source drive systems in this paper. Compared with the conventional line-side CL filter in the PWM current-source drives, the adoption of the proposed CL-LC filter not only saves the total size of line-side capacitor so that minimizes the reactive power flow through the line impedance, but also further attenuates the low-order dominant harmonics produced by high-power PWM current-source rectifier (CSR). As a result, the input power factor of the drive system is effectively improved. Simulation and experimental results are provided to verify the effectiveness of the proposed filter.