Enhanced Modeling of Wireless Power Transfer System with Battery Load

This paper presents an enhanced mathematical model for the wireless power transfer (WPT) system with a battery load and uncontrolled rectifier at the receiver side. The WPT system is decomposed into two subcircuits using the superposition theorem. By calculating the phase difference between the fundamental wave of the inverter output voltage and that of the rectifier input voltage, various electrical parameters including voltage, current, power, efficiency, and input impedance angle are derived. In addition, the effect of rectifier parasitic capacitance is also considered. To demonstrate its precision, the proposed model is compared to the constant-resistance and variable-resistance load model using numerical simulation software (SIMULINK) as a reliable reference. Finally, simulation and experiments are carried out to validate the theoretical analysis.