A Sensing Coil in Inductive EV Charging Systems for Estimating the Coupling Coefficient and Receiver Resonant Frequency

This paper presents a novel framework for the construction and implementation of a sensing coil in wireless Inductive Power Transfer (IPT) systems, specifically aimed at observing and predicting the coupling coefficient as well as the receiver-side resonant frequency in LCC-S compensated systems of the receiving coil. remains an enigma. The method revealed here has universal applicability for wireless charging solutions, targeting Two, Three, and Four-wheeled vehicles, all without requiring prior knowledge of the specific parameters of the receiving coil. The sensing coil is disconnected from the transmitting coil, instead forming a link with the receiving coil to assimilate the phase data of the current flowing at the receiver end. A solitary zero-crossing voltage sensor is used to record the voltage across the sensing coil. The approach relies on two deliberate frequency sweeps designed to locate the point at which the AC output voltage aligns in phase or deviates in phase with respect to the AC input. This innovation enables meticulous approximation of vital parameters, thereby improving the accuracy and reliability of wireless inductive power transmission systems.