New Control Method for Receiver-Side DC-DC Converter With Large Stability Margin and Fluctuation Suppression Toward DWPT System

Dynamic wireless power transfer (DWPT) system is applied to electric vehicles, medical treatment, communication, and many other fields. Usually, a dc-dc converter is cascaded at the receiver side to suppress output fluctuation caused by mutual inductance change in the moving process. However, there occurs instability in some conditions in the system under conventional topology and control method. This work proposes a new control method based on a dual buck-boost converter to handle the abovementioned two problems at the same time. It can, in theory, reduce the peak-peak and average values of dc inductor current, meanwhile, increasing the converter efficiency. Also, it can improve the stability margin of the whole system. In this article, we use a simulator to replace the actual DWPT system. Through the simulator, the WPT system can produce the same fluctuating output voltage as that under dynamic conditions to support experiment. The stability of the system is explored by constructing the small-signal model of the system. Then, the effectiveness of the method is proved by simulation and experimental results.