Parameter-Identification-Based Impedance Tuning Method
摘要
This chapter introduces a parameter identification–based impedance tuning approach to mitigate impedance mismatch arising from capacitance drift and coil misalignment in IPT systems. The method begins with an identification algorithm that determines the unknown resonant circuit parameters using only the RMS values of the coil currents, eliminating the need for phase detection circuitry or auxiliary sensing coils. Based on the identified parameters, the system reactances on both sides are simultaneously minimized through coordinated adjustment of the operating frequency and the active rectifier’s phase shift angles. Unlike conventional techniques, the introduced identification process employs a dynamic frequency–tracking mechanism that prevents severe detuning caused by bifurcation effects. Furthermore, the impedance tuning strategy compensates for parameter variations on both sides without requiring additional circuits or switches. Experimental validation confirms accurate parameter recognition, with average relative errors below 3%, and demonstrates a DC-to-DC efficiency improvement of 4.3–15% on the IPT prototype.