A Comparative Study of S-S and LCCL-S Compensation Topologies in Inductive Power Transfer Systems for Electric Vehicles

Abstract

In inductive power transfer (IPT) systems, series–series (S-S) and double capacitances and inductances–series (LCCL-S) compensation topologies are widely utilized. In this study, the basic characteristics of S-S and LCCL-S are analyzed and compared in the tuning state. In addition, considering the universality of detuning, and because the two topologies have the same secondary structures, the voltage and current stress on components, input impedances, voltage gains, and output powers of S-S and LCCL-S are mainly analyzed and compared in the detuning state, which is caused by variations in the secondary compensation capacitance. To compare the efficiency of the two topologies and verify the comparative analysis, comparative experiments based on a 2.4-kW IPT experimental prototype are conducted. The comparative result shows that the S-S compensation topology is more sensitive to load variations and less sensitive to secondary compensation capacitance variations than LCCL-S. Both in the tuning and detuning states, the efficiency of the S-S topology is higher in high-power electric vehicle (EV) applications, and the efficiency of LCCL-S is higher in low-power.