Abstract—In this study, we evaluated a three-phase power supply to improve input power quality for the capacitive charging and discharging application. The power supply consisted of three flyback inductors, and microcontroller to generate switching pulses and film capacitor for high-energy charging and discharging. Two of three discrete power switches successively switched on with overlapped 60° of phase to make the current flows continuously. From the computer simulation, we confirmed this method achieves 1.3% of Total Harmonic Distortion (THD) and power factor of 0.96. Also, the input current waveform follows the input voltage waveform. To verify the proposed method, we implemented and tested the prototype system. Through the experiments, we confirmed the total harmonic distortion was 2.7% and the power factor was 0.94 in 50 Hz discharge condition with maintaining 1,200 charged voltages in high-voltage capacitor.