Charging ahead: Unlocking the potential of constant voltage and constant current modes in WPT for EVs

The increasing interest in Electric Vehicles (EVs) is driven by the quest for alternatives to traditional internal combustion engine vehicles to minimize the environmental pollution. At the early-stage EV industry struggled due to limited invention in the battery technology and charging infrastructure inadequacies. However, recent advancements in battery technology, particularly with lithium-based batteries, have propelled the EV market forward. This advancement has also spurred innovations in wireless EV battery charging, offering a more convenient solution. Despite the advantages of lithium-ion (Li-ion) batteries, such as enhanced performance, they face limitations like sensitivity to temperature changes and higher costs, necessitating robust charging systems. Research has been focused on improving charging efficiency through advancements in both conductive and wireless charging methods. However, challenges such as airgap distance, misalignment tolerance, and frequency limitations persist, impeding optimal efficiency in wireless charging systems. Designing a charging infrastructure adhering to wireless standards and employing efficient operational modes is crucial for achieving high efficiency and prolonging the lifespan of the battery. Constant Voltage/Constant Current (CC/CV) charging is a prevalent method for Li-ion battery charging, with researchers exploring various approaches to implement this mode within wireless power transfer (WPT) systems for EV batteries. This review article delves into the intricacies of CC/CV charging techniques applied to WPT systems, outlining different charging methodologies along with their attributes. It examines control methodologies employed in CC/CV charging and discusses their implementation, including advantages and drawbacks. By consolidating the challenges associated with CC/CV methods, this article suggest the converter control approach for better regulation with less complexity and reconfigurable topologies for minimizing the number power electronic switches and switching loss with more passive elements and design complexity.