Design of Active Power Filter for Low Voltage and High Current Switching Power Supply

Switching power supply of low voltage and high current based on power electronic technology is widely applied in some industry fields, especially in electroplating, welding and heating. Harmonics in high-power switching supply pollute power system heavily, which must be suppressed effectively. On basis of analyzing harmonic current of switching supply that the output technical specification is 60V/500A, this paper designs active power filter for switching power supply with high power and frequency, which adopts ip-iq current detecting method and hysteresis current control method. Based on simulation platform of Matlab/Simulink, the filtering effect is simulated and analyzed. Simulation results demonstrate the active power filter has expected performance, which can not inhibit harmonic current instantaneously, but also compensate reactive power. The designed active power filter can effectively improve the power quality.