Impact of Capacitor Dielectric Type on the Performance of Wireless Power Transfer System

In loosely coupled wireless power transfer systems, the efficiency is directly affected by the quality factor of the resonant LC tank in both the transmitter and the receiver. This paper studies the impact that the capacitor dielectric type has on the quality factor of the resonant LC tank. Experimental investigation is conducted for low ESR capacitor types and the performance of the wireless power transfer system is evaluated. Focus of the experimental evaluation is placed on the receiver's end, i.e. the evaluated parameters are current-voltage characteristics of the receiver and maximum power values. Capacitors are also compared with respect to their ESR values on different frequencies and price. The results show that the capacitor type has a significant impact on the performance of the wireless power transfer system. The correct choice of capacitor type can increase the efficiency of power transfer and the maximum achievable power up to 400 %.