Sensorless Control of Series-Series Tuned Inductive Power Transfer System

Conventional inductive power transfer (IPT) system controllers require high-speed wireless communication since the transmitter and the receiver are physically isolated. This wireless communication and its data loss and delay issue are the key barriers to the IPT system in achieving a high bandwidth controller. In this study, a transmitter-oriented sensorless controller for a series-series tuned IPT (SS-IPT) system is proposed. The proposed sensorless controller makes a closed-loop control of the receiver-side voltage and current using estimated receiver voltage and current as feedback. A cascaded receiver voltage and transmitter current controller with disturbance and cross-coupled state decoupling technique is proposed. Since the proposed controller uses estimated voltages and currents of the receiver, it does not require wireless communication. The proposed receiver voltage controller achieved 200 Hz of control bandwidth without wireless communication. The command tracking and disturbance rejection performances of the proposed sensorless control system were evaluated using circuit simulation and experimental results. The simulation and experimental results agreed well and the measured control bandwidths of the cascaded control system agreed with the theoretically calculated bandwidths.