A Push–Pull Parallel Resonant Converter-Based Bidirectional IPT System

Bidirectional inductive power transfer (BD-IPT) systems facilitate wireless grid integration of electric vehicles to offer vehicle-to-grid (V2G) services. This paper presents a novel push-pull parallel resonant converter-based BD-IPT system to provide a more efficient and cost-effective solution to wireless V2G technologies. The proposed system integrates the functionality of bulky passive elements into a double-D type magnetic coupler to achieve high power density. A phase-delay control technique is proposed to reduce the startup transients as well as to regulate bidirectional power flow between the primary and secondary sides of the push-pull converters. A zero-voltage switching zone is identified to maintain safe operation of the system. Both the operating principles and control philosophy of the converters are described, and a detailed mathematical analysis is presented. The effectiveness of the proposed system is verified by building a 3.3-kW prototype system. The experimental results show that the peak power transfer efficiency reaches 96.5%, and the efficiency remains high under a wide range of operating conditions.