Design and Control Methods for Electric Vehicle Charging in Wireless Power Transfer Topologies

Abstract

In this paper, different designs and controls of several wireless power transfer (WPT) topologies are comprehensively studied for battery charging. Most WPT topologies exhibit inherent constant voltage (CV) or constant current (CC) output characteristics. The paper systematically studies numerous WPT topologies to find these natural CC or CV characteristics. The battery requires combined CC and CV charging, which requires additional control, such as primary, secondary, and dual-side control. Different closed-loop control schemes are meticulously studied, reporting their merits and demerits, further delving into several works that attempted to combine two different WPT topologies using a switchable network to achieve a natural CC/CV charging without additional closed-loop control. This work also focuses on different WPT topologies exhibiting two or more resonant frequencies that achieve the CC and CV charging profile at two distinct frequencies. In addition, the growing popularity of the CP charging profile, which is known for its faster charging capability and compact thermal design, is explored. A sensitivity analysis compares the performances and robustness of the natural CC or CV characteristics of the different topologies when the WPT coil and compensation circuit parameters have a ±10% tolerance.