A Fast Construction Method of Resonance Compensation Network for Electric Vehicle Wireless Charging System

Abstract

When constructing an electric vehicle (EV) wireless charging system, limited by manufacturing technology and measurement errors, the capacitance and inductance in the impedance matching network will inevitably produce parameter deviations, which will cause tuning difficulties and even burn the power supply. In order to solve these problems, this article proposes a fast and accurate tuning technique based on a double-sided L3C compensation network with a capacitor matrix. The tuning method derived from theoretical analysis can be summarized as: tuning capacitor can achieve fast matching; fine adjusting the equivalent inductance can achieve precise matching and power zero-voltage switching. After resonance matching, the capacitors on the capacitor matrix can be removed and welded together, and an inductor can be used instead of equivalent inductance, so the technology is low cost, fast, and safe. In order to verify the tuning method, a 3-kW EV wireless charging system was developed. Experimental results show that the proposed method makes the system resonate rapidly and maintain stability, and the inverter is also easy to implement zero-voltage switching.