Design of the LCC-SP Topology With a Current Doubler for 11-kW Wireless Charging System of Electric Vehicles

Abstract

In this article, an 11-kW wireless charging system based on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> -serial–parallel (SP) topology utilizing the power control of a current doubler is established. The circuit characteristics of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> -SP topology are analyzed. Furthermore, the equivalent quality factor is introduced to analyze the harmonic problem of the system. Meanwhile, the equivalent impedance of the current doubler is derived by Fourier decomposition. Then, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> -SP compensation parameters are modified according to the derived equivalent impedance. Considering the above harmonic problem, the system loss, and the equivalent impedance correction of the current doubler, an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> -SP parameter design scheme is proposed. To ensure a constant power output at different horizontal offsets, the closed-loop controller is investigated by establishing the small-signal model of the current doubler. Finally, an 11-kW wireless charging prototype with power regulation capability is constructed, which verifies that the system can maintain an 11.014-kW output power and a 91.286% system efficiency even at the maximum horizontal offset.