Research On Series Resonant High Voltage Capacitor Charging Power Supply

The discharging of the high voltage capacitor is used widely in the pulsed power area, and the rapid charging of capacitor is important. High frequency series resonant capacitor charging power supply (CCPS) is introduced in this paper for its constant charge current and the strong immunity of short circuit.This paper presents the research and development work on series resonant high voltage CCPS. By steady state analysis of resonant circuits working in discontinuous current mode (DCM) in series resonant CCPS, three functional relationships between peak value of resonant current, peak value of resonant voltage, voltage on load capacitor and numbers of resonant periods are found and the inherent constant-current characteristic, which disappears as the current through anti-parallel diodes declines to zero, are demonstrated. Furthermore, the precise time when the constant-current characteristic changes and the voltage on the load capacitor at that moment are calculated. The truth of theoretical analysis is testified by circuit simulation.The design steps of the CCPS, which is working in DCM, are given in details in this paper. Except the control circuit based on MC33066, which is used to guard the CCPS, display circuit, soft-start circuit, a fiber isolation circuit, over-voltage, the voltage reversal protection are designed in this paper to boost the stability of the high-voltage CCPS, improve charge precision in order to meet the perfect constant current charging effect.