Design, Development and Preliminary Analysis of a Battery Cell Equalizer Based on Resonant Electronic Transformer

Abstract

This work consists on the research and analysis of a modular Electronic Transformer (ET) suitable for working in a battery equalizer. The ET will consist on an resonant isolated converter where the resonant inductance is integrated in the transformer. A simulation of the system will first show how with a basic control of the input bridge, the equalizer works, but no zero current switching (ZCS) is achieved, thus, efficiency is low. Methods to reduce the peak current of the ET will be also shown. A specific gate control topology will be proposed in this work. The resulting modulated topology provides high efficiency through soft switching, being valid for simple battery cell equailizer as it does not require either a central control or feedback loops. The effect of tolerances in the performance of the system will be finally assessed.