Resonant Based DC-DC Converter for Fast EV Battery Charging Applications Using Novel Adder Architecture - Analysis, Design & Resonant Components Tolerance Effects

Consistent efforts are being made to enable electrification of the transport industry for a cleaner environment. Though there has been substantial increase in electric vehicles (EVs); lack of adequate and quick charging points are proving to be major stumbling blocks to the wide spread adoption of electric vehicles. This paper presents a novel multi-module series connected dual active bridge resonant DC-DC converter with a unique adder configuration for obtaining wide output voltage (150V - 920V) for EV battery charging applications. The system is conceived with the ability to connect multiple modules in parallel to facilitate the fast charging. A detailed analysis is performed to select components and also to briefly highlight the adverse effects of component tolerances in these multi-module systems. The manuscript suggests a simple modification in the temporal characteristics of waveform generated by the converter for addressing the component variation problem. A scaled down experimental prototype (voltage range of 42V-223V and power range of 0.2kW - 0.875kW) showing 95.5% peak efficiency is built to demonstrate proof of concept.