An LCC Wireless Charger with Embedded Cell Equalization via a Shared Compensation Inductor

This paper presents an integrated approach for achieving simultaneous battery charging and balancing in wireless power transfer (WPT) systems, unifying both functions within a single, compact circuit topology. The proposed design repurposes the receiver-side compensation inductor as the primary winding of a multi-winding transformer, enabling the balancing function to be realized without introducing additional magnetic components or control circuits. Balancing voltages and accurate inter-cell energy redistribution are governed by the transformer's turns ratio, allowing precise regulation without auxiliary converters or switch matrices. Consequently, the system avoids the multiple receiver coils and complex switching networks typical of conventional WPT equalizers, leading to notable reductions in cost, volume, and control complexity. Furthermore, the topology ensures accurate balancing without stringent coupling consistency and remains stable under coil misalignment, highlighting its robustness to mutual inductance variations. These attributes make the system particularly suitable for dynamic or mobile energy storage applications. Experimental results validate the proposed equalizer, demonstrating a charging efficiency of 81.5% at a 19 W load while maintaining inter-cell voltage deviations below 0.02 V. These results demonstrate that the proposed method offers a compact, reliable, and scalable approach for integrated battery management in WPT-enabled systems.