Design of passive power filters for a three-phase semi-controlled rectifier with typical loads

This paper presents the design and simulation of AC and DC passive power filters for a three-phase thyristor-based rectifier. On the source side, the purpose is to achieve harmonic current suppression and reactive power compensation and on the load side, to eliminate the DC voltage ripple. After a brief review of most common filtering methods, the paper emphasizes on the necessity of passive techniques for high power applications. The AC filter consists of RLC branches tuned to harmonic frequencies, while the DC filter inserted at the rectifier output includes a series inductor and shunt connected resistor and capacitor. Matlab/Simulink is the software used for building and simulating the filter models, in the two cases of DC inductive and capacitive loads. The results obtained before and after filtering demonstrate its efficiency in improving the waveforms quality on both AC and DC sides, and therefore in the optimization of power consumption.