Frequency Regulation Scheme for Double-Sided LCC Compensated Inductive Power Transfer Systems With Quasi-Load-Independent Outputs

Double-sided LCC (LCC-LCC) compensated inductive power transfer (IPT) systems are extensively employed in high-power-level applications, such as electric vehicles. The utilization of a high-order compensation network enables the achievement of quasi-load-independent output (QLI) across multiple frequencies. However, the QLI frequencies are typically influenced by the coupling conditions and system parameters. Consequently, calculation errors in QLI frequencies arising from parameter drifts are unacceptable. In this paper, an improved frequency control scheme for LCC-LCC IPT systems by regulating the phase difference angle between the primary side voltage and the receiver side current is proposed. The prioritization of QLI frequencies is based on energy efficiency. An LCC-LCC-compensated IPT system is built in practice and the output voltage deviation is less than 7% for the load changed from 40Ω to 20Ω.