Comparison and selection strategy among compensating topologies in two-coil resonant wireless power transfer systems

In this study, different compensation topologies for two-coil resonant wireless power transfer systems were compared. Compensation circuits were examined individually according to system parameters such as efficiency, equivalent impedance, frequency, load resistance, and phase angle. System variables were compared to address the constraints on system applicability regarding compensation topology selection in Wireless Power Transfer (WPT) systems. The main motivation of this study is to present a suitable topology selection scheme and flow diagram based on applications with various voltages, currents, powers, and loads. Simulations carried out using Simulink for the four main topologies under various load conditions indicated that choosing the proper compensation topology for an appropriate load is essential. The simulation results were validated using both Matlab and C # calculation codes. Analyses according to frequency under various load conditions show that efficiency variations depend on the compensation topology of the receiver side. Furthermore, this study revealed that the topology of the transmitter side only affects the equivalent impedance and amount of power drawn from the input; hence, it has no effect on the efficiency and load characteristics. Consequently, for low-load resistance, such as electric vehicle or mobile phone charging, topologies with series compensation on the receiver side are preferred. Correlatively, topologies with parallel compensation on the receiver side can be evaluated as suitable for high-load resistance, low-current, and low-power operations, such as biomedical appliance charging.