Compensation Considerations for Bidirectional Inductive Charging Systems of Electric Vehicles With Coil Positioning Flexibility

Bidirectional inductive power transfer (BIPT) systems enable power transfer between stationary electricity sources and movable consumers in each direction through electromagnetic coupling. Due to its complexity, a mathematical model is required to design and to control these systems. This paper presents the mathematical analysis and the frequency-domain analysis for two different compensated (series-series and parallel-parallel) BIPT systems. This paper contains the modeling procedure of the BIPT system's coils in the frequency domain. The prediction of its equivalent circuit values, magnetic stray field values, and coil positioning tolerance are determined as well using the JMAG field simulation software. Furthermore, the transmission characteristics and the efficiency of the two compensation topologies are discussed.