Constant Current/Constant Voltage Charging Via Series-Series Compensated Resonant Inductive Wireless Charging for Electric Vehicle

Abstract

This paper presents the simple yet effective phase shift control to attain constant current/constant current (CC/CV) charging for Electric Vehicle (EV) battery packs through series-series compensated resonant inductive wireless power transfer (RIWPT). The Series-Series (SS) compensation is mainly used in the proposed system to improve power transfer capability, reduce the leakage magnetic flux, and thereby maximize the power transfer efficiency. The battery pack of EV s is characterized as an equivalent variable resistance during CC/CV charging based on a real charging profile of a Chevy bolt EV battery pack. The primary side control is utilized in the proposed system to reduce the weight of the onboard power electronics converter and components requirements on the secondary side. An effective phase shift control strategy for RIWPT -based level 2 charger which only requires battery voltage and current data is implemented to achieve CC/CV charging of the EV battery pack. The effectiveness and practicality of the proposed control strategy are verified through a 7.7 kW RIWPT-based charger simulation as well as its experimental validation with a 3.7 kW RIWPT -based charger prototype.