An integrated PFC-WPT converter with reduced DC-link and optimized dual-sided LCC compensation for efficient AGV charging

Wireless power transfer (WPT) systems for automated guided vehicles (AGVs) typically operate under opportunity charging conditions, where charging occurs during short idle periods. This requires fast charging, making constant-current (CC) operation particularly suitable, while also demanding compact and reliable system design. This paper proposes an integrated PFC-WPT converter with an optimized dual-sided LCC compensation network. In the proposed topology, the AC–DC and DC–AC conversion functions are tightly coupled without an intermediate energy buffering stage, where only a small film capacitor C bus is employed instead of a bulky DC-link capacitor. This results in a unified power conversion structure with a significantly reduced DC-link requirement. An optimized design guideline for the dual-sided LCC network is identified, showing that maintaining γ ≈ 0.88 enables transfer efficiency above 98% over a wide load range, with low sensitivity to load variations. In addition, a simplified control scheme based on DC phase-shift modulation is adopted, which reduces control complexity compared to conventional sinusoidal modulation while enabling accurate constant-current charging and soft-switching operation. Experimental results validate the proposed converter, demonstrating stable ZVS operation for all switches, an overall system efficiency above 93.5%, and high input power quality with low harmonic distortion.