Advances in Leakage Current Suppression for Dynamic Wireless Power Transfer System

This paper presents a systematic investigation into the research progress on leakage current suppression in N-leg inverters for dynamic wireless power transfer (DWPT) systems.With the widespread adoption of electric vehicles, DWPT technology has emerged as a critical solution due to its convenient and efficient charging capabilities.As a core transmitter-side topology, the N-legged inverter significantly enhances system scalability by reducing the number of switches from 4n in conventional full-bridge inverters to 4+2n.However, this architecture introduces new leakage current challenges stemming from voltage disparities in standby coils, leading to copper losses and electromagnetic interference (EMI) that compromise system efficiency and safety.Addressing these challenges, this study comprehensively reviews two predominant suppression strategies: the short-pulse control method and the pulsewidth phase modulation method.After analyzing the limitations of these approaches, the paper proposes enhanced control strategies extended to n-leg configurations, emphasizing the critical importance of synchronizing all standby bridge arms in multi-vehicle charging scenarios to prevent additional power consumption and resonance issues caused by asynchronous operation.Ultimately, this research provides essential technical references and practical guidance for leakage current management, topology optimization, and efficient deployment in DWPT systems.