Wireless Constant‐Current Constant‐Voltage Charging of Electric Vehicle Battery From Transmitting Side Control of DC Bus Voltage of Single Phase Boost PFC Rectifier

ABSTRACT

In wireless charging of the EV, a high‐frequency rectifier, compensation circuit, and a DC‐DC converter are used on the receiving side to charge the EV's batteries. The receiving side circuit becomes more complex, and the cost goes high. The proposed method's receiving side circuit is simple, and only a compensation circuit with a high‐frequency rectifier is used. The battery is connected at the output of a high‐frequency rectifier terminal, and battery charging current and terminal voltage can be controlled by varying the RMS output voltage of the inverter on the transmitting side. Two types of transmitting side control can be used. First is controlling the pulse width of the H‐bridge inverter switches, which is generally used in the transmitting side control. Second is the proposed method that controls the magnitude of the input DC voltage of the inverter. In a grid‐fed wireless power transfer system, a single‐phase PFC rectifier supplies power to the high‐frequency inverter, and the high‐frequency inverter supplies power to the coil system. In the proposed method, feedback of the receiving side battery charging current and terminal voltage data are sent to the transmitting side by wireless communication. This data is used to control the output voltage of a single‐phase PFC rectifier, and this voltage is the input DC voltage of the H‐bridge inverter. The battery requires a charging current, and the terminal voltage can be controlled by varying the output DC voltage of a single‐phase Boost PFC rectifier. In this paper control method of a single‐phase PFC rectifier is shown to achieve constant current and constant voltage on the receiving side. The coupling coefficient between the coil and the self‐inductance of the coil is calculated with the help of FEM software. The hardware prototype result is shown to validate the proposed wireless charging strategy of EV is demonstrated to charge a 48V battery of 2.4kWh rating and validated for effectiveness.