Bidirectional multi-resonant converter with a wide voltage range

Abstract

A bidirectional multi-resonant DC/DC converter is proposed in this study. The structure of the converter is symmetrical, and the operating characteristics of the bidirectional operation mode are the same. Adopting synchronous driving, the converter can regulate the output voltage over a wide range. Regardless of a forward mode or reverse mode, the switches of the converter can realise zero-voltage switching over the entire voltage range. The gain of the converter can be zero due to its characteristics similar to the notch filtre. The converter can transmit the fundamental wave and the third harmonic at the same time, and the energy utilisation rate is high. The converter has a wide voltage range and high efficiency at the same time. A 3.3 kW experimental prototype is designed. In forward mode, the secondary-side voltage varies from 250 to 450 V, and the peak efficiency is 97.7%. In reverse mode, the secondary-side voltage varies from 300 to 450 V, and the peak efficiency is 97.6%.