An S-S Compensated WPT System for Electric Vehicle Battery Charging with Capacitor Matrix

In the static wireless power transfer (WPT) system for electric vehicle (EV), constant output current (CC) and constant output voltage (CV) mode needs to be applied for better battery charging quality. In this paper, a series-series (S-S) compensated wireless charging system with capacitor matrix is proposed. By detecting the primary winding current and secondary output voltage, the mutual inductance between the primary coil and secondary coil can be calculated. With wireless communication between the primary side and the secondary side, the compensated capacitor matrices on both sides are controlled base on the mutual inductance and battery charging voltage. The CC/CV mode for battery charging can be achieved by changing the value of the capacitor matrices. Based on the simulating and experimental results, constant output current and voltage can be generated by switching different compensated capacitors, an easy control of EV battery CC/CV charging is thus realized.