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

Abstract

In this study comparisons of different compensation topologies are investigated for two coil resonant wireless power transfer systems. Compensation circuits are examined individually according to system parameters such as efficiency, equivalent impedance, frequency, load resistance, and phase angle. This paper aims to compares the system variables in order to address the constraints in the system applicability regarding the compensation topology selection in WPT systems. Simulations performed for four main topologies under various load conditions concludes that choosing the proper compensation topology for appropriate load is essential. The analyses according to the frequency in various load conditions have shown that the variation of efficiency depends on the compensation topology of the receiver side. Moreover, in this study, it has been revealed that the topology of the transmitter side only affects the equivalent impedance together with the amount of power drawn from the input hence it has no effect on the efficiency and load characteristics. Consequently in the case of working with low load resistance such as an electric vehicle or mobile phone charging, topologies with series compensation on the receiver side (SS and PS) can be preferred. Correlatively, topologies with parallel compensation on the receiver side (SP and PP) can be evaluated as suitable for high load resistance, low current, and low power operations such as biomedical appliance charging.