Novel Synchronous Rectification and Receiving Power Compensation Method for WPT Only by DC Current Sensor

Abstract

Dynamic wireless power transfer can solve the shorter cruising rangeproblem of electric vehicles. The synchronous rectification can improve the efficiency of wireless power transfer, but it costs more because it requires an expensive ac current sensor. A novel synchronous rectification method is proposed which only uses an inexpensive dc current sensor and does not measure ac current or voltage. This method continuously searches the synchronous state by the gradient descent method and the feedforward phase jump control. This method also compensates for the decreased received power caused by the deviation of the parameters. In the first part, it is explained by the equivalent circuit model that the proposed method can achieve synchronous rectification by maximizing the dc received current. Then, the effectiveness of the proposed method in terms of the efficiency and the received power is verified in the experiment by comparing it with the conventional diode rectification. The proposed method reduced the loss by 31.77% and achieved synchronous rectification four times faster.