Considering Losses to Enhance Circuit Model Accuracy of Ultrasonic Wireless Power Transfer System

Ultrasonic wireless power transfer (UWPT) has been a promising technology to recharge the sensor batteries that locate in enclosed metal containers. An accurate and comprehensive analytical model is the key enabling tool for designing the UWPT system. In this article, a novel equivalent circuit model has been proposed for a typical UWPT system with two symmetric piezoelectric transducers bounding onto an aluminum plate coaxially. The proposed model is a two-port network equivalent circuit that can be described by T parameters. By considering the losses of the UWPT system, the accuracy of this model has been enhanced in comparison with the widely used equivalent circuit model, which ignores its losses. The experimental results show that the average error of output power decreases about 6.4 times in the proposed model compared to the existing model. Moreover, the proposed model is tested under various working conditions to validate the enhanced accuracy.