Current Sensorless ZPA Frequency Tracking Control of IPT System with LCCL-S Topology

Inductive power transfer (IPT) systems for electric vehicles (EVs) should apply zero-phase angle (ZPA) frequency control methods for achieving low VA rating and high efficiency. In order to apply ZPA frequency control, current sensors are needed in previous studies. However, these sensors have several problems using for ZPA frequency control such as switching noise, degrading control performance, control complexity, and so on. Therefore, this paper proposes the simpler control method without current sensor for ZPA frequency tracking with LCCL-S topology of IPT systems. The optimal design point is also deducted to apply the proposed control. A simulation and an experiment of 3.3-kW IPT system are performed to verify the proposed control.