Novel split impedance-matching-architecture to reduce EMI and current in the interconnection cable of a two box WPT system for EV charging

In a two-box Wireless Power Transfer (WPT) system for Electric Vehicle (EV) charging application, the interconnection cable is one of the most expensive and heaviest components. This is because it must carry over 30A with an 85.5 kHz current for WPT 3 class. Due to this high-frequency current, many strands of small-diameter Litz wire should be used. Additionally, this cable is quite long, with a length ranging from 3 m to 7 m. As a result, the cable functions as an antenna and radiates electromagnetic noise. To address these challenges, reducing the current and Electromagnetic Interference (EMI) from interconnection cable can significantly cut down on the cost and weight of the cable and filters. In this paper, we introduce a new architecture called the split impedance matching architecture to achieve this goal. According to our measurements, this novel architecture can reduce the current in the interconnection cable by up to 48% compared to the inverter output current. Furthermore, another advantage of this approach is that it can decrease the DM (Differential mode) noise current by up to 60 dB at the highest attenuation frequency.