Sliding-Mode Control of Dynamic Wireless Charging EV System

The main challenge of electric vehicle (EV) dynamic wireless technology is the fluctuation of mutual inductance caused by the movement of EV, which leads to the instability of system. Based on the variable structure control, this paper proposes the output power regulation method of EV. Firstly, we use Biot-Savart Law to derive the mathematical expression of mutual inductance between transmitter and receiver of dynamic wireless charging (DWC) system. According to the mathematical expression, mutual inductance is related to the lateral misalignment, longitudinal offset and vertical distance of the transmitter coil and receiver coil. Then, the state space equation based on Kirchhoff's voltage / current law is established for DWC system. Finally, in order to ensure the stability of the output power, a sliding mode controller is used to adjust the transmitted power for the DWC system and track the reference input. Through simulation, it is proved that the system output is consistent under the condition of mutual inductance fluctuation brought by the relative distance change between transmitter and receiver.