Design of Back-End Compensation Network Parameters in WPT System with Anti-Offest Performance

Wireless power transmission (WPT) systems require the ability to transmit power smoothly across a wide range of coupling coefficients. Traditional resonant series-series compensation structures are sensitive to coupling mechanisms and are not suitable for applications where coupling coefficients vary significantly. Additionally, when coupling coefficients are too low, they can easily cause overcurrent issues. This paper introduces a detuning parameter design on the primary side of the series-series compensation topology to reduce sensitivity to coupling mechanism shifts. Based on circuit theory, a “T1T2” type compensation network composed of positive and negative Γ-type resonant cavities is introduced on the secondary side, and network parameters are designed to achieve stable output power of the WPT system over a wide range of coupling coefficients. A simulation platform was established using Matlab/Simulink software for verification. Simulation results show that within the coupling coefficient ranges of (0.11, 0.179), (0.184, 0.277), and (0.284, 0.411), the output power fluctuation is below $10 \%$, proving the effectiveness of the proposed parameter design method.