Estimation of the Transferred Power in LCC Compensated Wireless Power Transmitters With the Use of PWM-Synchronized Sampling Technique

Abstract

In this article, a new technique of synchronized sampling to estimate the transferred power in wireless power transfer (WPT) systems is proposed. Defining demand factor as a criterion linking unknown receiver parameters to the transferred power, it can be estimated by measuring the front-end variables of the transmitter <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> compensating network. Moreover, with the use of this technique, one does not need to know how the mutual inductance or load varies. As the demand factor is directly linked to the transferred power, the estimation of the demand factor can be considered as an increasingly effective way to control the flow of power in WPT systems. To prove the validity of this approach, a WPT system equipped with an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> network to compensate the transmitter, and a series capacitor to compensate the receiver, is experimentally built and tested, and the results show a close consistency between the measured demand factor and the transferred power.