A parameter correction method for bilateral LCC compensated wireless power transfer system

The deviation of the factory parameters for inductors and capacitors in the LCC compensation network, along with a significant reduction in capacitance values due to capacitor aging and other device degradation, can lead to a shift in the circuit’s resonant frequency away from the switching frequency. It leads to the deviation of the system output current from the set constant-current characteristics, which can cause the system load-bearing capacity and the system efficiency to drop significantly in severe cases. A variable equivalent capacitance circuit composed of capacitor C and reverse series switching tube in parallel is proposed. Its operating modes are analyzed and an equivalent capacitance mathematical model is established. An Improved Sparrow Search Algorithm (ISSA) is proposed to optimize the capacitance parameters of $C_{1}$ and $C_{2}$ in the parallel branch of the LCC compensation network by minimizing the output current offset under different loads, taking into account the internal resistance of the compensation network components. The switching control capacitor is employed to replace $\mathbf{C}_{1}$ and C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, leading to the construction of a comprehensive system simulation model. The phase shift angle is adjusted to ensure that the equivalent capacitance of both branches attains the optimal value required by the system. Simulation results indicate that during load changes, the deviation in output current remains within $\pm 8 \%$, demonstrating that the system exhibits excellent constant-current output characteristics.