A Symmetrical Impedance Compensation Configuration for Optimized IPT Systems

This paper presents a double-sided Z-configuration-based compensation network for an inductive power transfer (IPT) system for electric vehicles (EVs) with detailed analysis and optimization factors as an alternative to the double-sided LCC configuration. The contributions of the proposed article are as follows: (a) a double-sided Z-compensation configuration is developed, which provides a lower voltage and current stress on the passive components in comparison with double-sided LCC compensation; it has inherent zero phase angle properties for minimizing losses and improving system efficiency; (b) the Z-Z configuration achieves a load-independent constant voltage output and constant transmitting current; (c) additionally, the optimized compensation factors for the primary and secondary sides are derived for maximum inter-coil efficiency. It is evident that fine-tuning the compensation factors can minimize copper losses and ensure high efficiency over a wide load range, achieving up to 93.37% efficiency at optimal conditions. Experimental results from the 1 kW laboratory prototype validate the proposed designs, demonstrating comparable power transfer performance with lower losses and an effective and alternative solution for double-sided LCC-LCC-based higher-power IPT systems.