Analyzing the Effect of Parasitic Capacitance in a Full-Bridge Class-D Current Source Rectifier on a High Step-Up Push–Pull Multiresonant Converter

Abstract

This paper presents an analysis on the effect of a parasitic capacitance full-bridge class-D current source rectifier (FB-CDCSR) on a high step-up push–pull multiresonant converter (HSPPMRC). The proposed converter can provide high voltage for a 12 VDC battery using an isolated transformer and an FB-CDCSR. The main switches of the push–pull and diode full-bridge rectifier can be operated under a zero-current switching condition (ZCS). The advantages of this technique are that it uses a leakage inductance to achieve the ZCS for the power switch, and the leakage inductance and parasitic junction capacitance are used to design the secondary side of the resonant circuit. A prototype HSPPMRC was built and operated at 200 kHz fixed switching frequency, 340 VDC output voltage, and 250 W output power. In addition, the efficiency is equal to 96% at maximum load. Analysis of the effect of the parasitic junction capacitance on the full-bridge rectifier indicates that it has a significant impact on the operating point of the resonant tank and voltage. The proposed circuit design was verified via experimental results, which were found to be in agreement with the theoretical analysis.