Application of parallel resonant converter operating in discontinuous current mode

Abstract

The parasitic parameters of high voltage,high frequency and high power transformers have important influence on converter operation. So the converter adopts resonant operation and makes use of leakage inductance and parasitic capacitance of the high voltage transformer as parallel resonant tank. In order to reduce switching losses of the power switches,discontinuous current mode(DCM) was adopted. So zero-current switching(ZCS) turn-on and zero-voltage,zero-current switching(ZVZCS) turn-off of the power switches were achieved. By mathematic analysis of converter operation,an analytical expression was derived to describe characteristics of the converter. The voltage regulation was given in detail. The results give guidance for the design of parallel resonant converter in high voltage,high frequency and high power applications. A 50 kV/22 kW output prototype was built to verify the theoretical analysis.