An Precise Frequency Tracking Technique Based on Short Current Detection

Abstract

This paper suggests a short current control method to eradicate the short current by regulating the switchingfrequency to method the inherent frequency. When systemrunning in force resonant mode, there will exist dangerousshort current between the resonant network and the switchingnetwork when switching frequency drifts away from inherentfrequency of the resonant network.Inductive Power Transfer (IPT) systems for transmitting tens to hundreds of watts have been reported for almost a decade. Most of the work has concentrated on the optimization of the link efficiency and have not taken into account the efficiency of the driver. A novel frequency tracking method based on short current detection is proposed for IPT applications. In addition, an instantaneous short current detection method utilizing cheap comparator is proposed. Furthermore, a fast and accurate tracking method is proposed to calculate the frequency mismatch and make a correction. The method can realize accurate frequency correction in several oscillation periods.