A New Power Converter Design for Electrical Vehicle Inductive Wireless Power Transfer Charging With Zero Common-Mode Current

Inductive charger systems are a technology that transfers power wirelessly by magnetic coils to charge the battery of electrical vehicles. In these systems, there are common mode voltages that due to existing several parasitic capacitances between the magnetic coils, heat-sink of semiconductor switches, and DC-link capacitors, with the system ground following a common mode current. To suppress the common current, they employ common mode chokes which increase volume, size, cost, and power losses. Besides, the coupling parasitic capacitance generates high electromagnetic interfaces. In this invention, a new converter is designed to have a zero common mode voltage which provides zero common mode current and reduces EMI emission. The designed converter uses the same number of semiconductor switches similar to an H-bridge converter with extra capacitors and discrete diodes. The proposed design is compared with the conventional inductive charger system in terms of functionality, common mode current, loss, and efficiency by theoretical and PLECS simulation. It demonstrates the proposal has a superior advantage in all aspects with higher efficiency.