Optimizing compensation topologies for inductive power transfer at different mutual inductances

Different compensation topologies of electric vehicle (EV) inductive power transfer (IPT) charging system in terms of transfer efficiency, required input voltage and input current, are compared and analyzed. Three compensation topologies are analyzed, namely series-series (SS), double-sided inductor-capacitor-capacitor (LCC-LCC) and double-sided capacitor-capacitor (CC-CC) topologies, at two mutual inductances between coils, namely 9.85 uH and 30.3 uH. The simulation and measurement results show that the SS topology produces a stable and higher transfer efficiency at high mutual inductance, while the LCC-LCC and CC-CC topology have a better transfer efficiency than the SS topology when used at low mutual inductance. This study shows how to select a compensation network for an IPT system to have the highest possible transfer efficiency at a given mutual inductance.