A Fully Soft-Switched Resonant Based DC-DC Converter using Adder Architecture for Fast EV Battery Charging Applications

Persistent efforts are being made to enable electrification of the transport industry for a cleaner environment. Though there has been substantial increase in the number of electric vehicles (EVs); lack of adequate and quick charging points are proving to be major stumbling blocks to the wide spread adoption of same. This paper presents a potential DC-DC converter architecture intended for fast battery charging applications. The converter is capable of generating wide output voltage (150V-920V) while maintaining soft-switching transitions for all the switches in the mentioned voltage range. It is conceived on the principle of adder architecture in which multiple power conversion modules are connected in a series-parallel combination for processing high power (55-175 kW). Detailed modelling and analysis of the converter is presented to select system components. A scaled down experimental prototype (voltage range of 36V-218V and power range of 0.32kW – 1.2kW) showing 97% peak efficiency is built to demonstrate proof of concept.