Evaluating Wireless Power Transfer Technologies for Electric Vehicles: Efficiency and Practical Implementation of Inductive, Capacitive, and Hybrid Systems

Abstract

This study evaluated wireless power transfer (WPT) technologies for electric vehicles (EVs), focusing on inductive (IPT), capacitive (CPT), and hybrid (HPT) systems. IPT utilizes resonant magnetic fields, CPT employs resonant electric fields, and HPT combines both methods to optimize the use of electromagnetic fields and electronic components. Pilot experiments were conducted using WPT standards and the relevant literature to investigate the efficiency and practical implementation of these WPT technologies. The evaluation included measuring system efficiencies with multimeters, assessing input and output waveform smoothness using oscilloscopes, detecting power losses through thermal scans, and monitoring electromagnetic field (EMF) exposure with EMF detectors. The results demonstrated that IPT achieved higher efficiency, smoother waveforms, and lower EMF exposure than CPT and HPT at lower frequencies. Moreover, IPT has a more straightforward circuit design owing to the lack of high-frequency components, further enhancing its practicality. The study also examined the effects of ground clearance and misalignment on WPT performance, and addressed safety concerns and potential solutions for all three types of WPT systems.