Design and Sensitivity Analysis of Dynamic Wireless Chargers for Efficient Energy Transfer

Abstract

Tunable Self-Oscillating Switching (TSOS) methods are a robust solution for tuning of Inductive Power Transfer (IPT) systems. However, they require deep analysis to be an appropriate choice for Dynamic Wireless Charging (DWC) systems. In this paper, the optimal operation point of TSOS in the maximum power transfer, efficiency, and Zero Voltage Switching (ZVS) realization perspectives are determined based on sensitivity analysis for DWC of Electric Vehicles (EVs). In the sensitivity analysis, all the possible states of the coupling factor and state of charge (SOC) are considered as system variables. Moreover, a new phasor modeling for constant voltage (battery) loads is proposed. The performance of this model is quite different from the conventional static model for the loads. Moreover, to limit the current of the charger under light couplings, a simple hysteresis controller is employed. A setpoint is proposed based on the sensitivity analysis method to transfer maximum energy in misaligned conditions. The proposed setpoint increases transferred energy and energy efficiency while limits the current of the charger. To analyze this method, simulation is done in the Simulink/MATLAB, and to verify the results, a laboratory prototype is implemented.

Keywords

• Electric vehicles
• inductive charging
• resonant inverters
• tunable circuits and devices
• zero voltage switching