Modeling and Assessment Analysis of Various Compensation Topologies in Bidirectional IWPT System for EV Applications

Electric vehicle (EV) can act as an energy consuming device or a distributed energy resource in the concepts known as vehicle-to-grid (V2G) and grid-to-vehicle (G2V). The bidirectional wireless power interface is a successful choice for this application, since it provides automatic, reliable, and safe operation. Therefore, this paper presents modeling and assessment analysis for the steady-state performance of bidirectional inductive wireless power transfer system (BIWPTS) in EV implementations. The analysis is presented for the three main compensation configurations: LC-series, LC-parallel, and LCL-topology. Moreover, the steady-state equivalent circuit-based mathematical models for all topologies are developed. These models were used to precisely determine the system response during V2G and G2V operations based on Fourier series. The study presents evident criteria to pick among the different BIWPTS structures in the diverse applications. The proposed analyses were verified both in simulation and experiment. The results demonstrate the ability of the proposed models to provide accurate estimation for BIWPTS performance under various operating and control conditions. Also, the evaluation analysis shows that LCL-topology is more appropriate for the bidirectional operation due to the simple design and control requirements, and being less sensitive to the misalignment.