Study of a Load-Independent LCC-S compensated WPT System with Variable-Inductor Variable-Capacitor (VIVC) Techniques

This paper proposes a novel LCC-S compensation wireless power transfer (WPT) system that integrates variable inductor (VI) and variable capacitor (VC) techniques for achieving load-independent output voltage in WPT systems. Through theoretical derivation and numerical simulation analysis, the realization of stable output voltage requirements is discussed. From the perspective of stable voltage gain, the integration of VI and VC modulation techniques is employed to enhance misalignment tolerance. Theoretical analysis demonstrates that adjusting the VI and VC to optimal parameters in response to the changes of the coupling coefficient can result in smoother variations of output voltage. This integrated approach offers high design flexibility and maintains stable system output even under a wide range of coupling coefficient variations, without the need for complex control requirements. Finally, through simulations, the proposed techniques in this paper are validated, showing that the output voltage fluctuation is less than 0.3% when the coupling coefficient changes by 333% (0.5 to 0.15), and the system efficiency remains above 94% throughout.