Sensitivity Analysis to Parameter Variations in LCC-S Compensated Inductive Power Transfer Systems

This paper focuses on the sensitivity analysis to parameter variations in a 1kW/85kHz LCC-S compensated inductive power transfer (IPT) system for electric vehicle (EV) applications. The impedance angle of the IPT system is sensitive to the compensation parameter variations, which will seriously affect the safe operation of the IPT system. Besides, the output power and efficiency will also be affected by those parameter variations. In this paper, mathematical models between impedance angle, output power, efficiency, and compensation capacitors are established, and the sensitivity of these indexes to compensation capacitor parameter variations is derived and analyzed by adopting the control variable method. Then, aiming at the effect of parameter variations on the IPT system, the methods of stabilizing the impedance angle and output power are discussed. Finally, a 1 kW IPT system was built to verify the validity of sensitivity analysis, all switches realize ZVS within the entire power range which can realize the reliable operation for the system, and 93.3% efficiency from de power source to battery load is achieved.