A General Design Method of Primary Compensation Network for Dynamic WPT System Maintaining Stable Transmission Power

Dynamic wireless power transmission (DWPT) is considered as a solution to the problems encountered in the development of electrical vehicle (EV), such as range anxiety resulted from battery bottleneck and the difficulty of convenient charging. However, the requirement of DWPT, maintaining almost constant transmission power with constant voltage load in effective movement process, is quite different from Stationary WPT. The power fluctuation is easily brought by the coupling coils over large misalignment in movement. A general design method of primary compensation network from the perspective of DWPT is presented in this paper. Under the premise of ensuring high transmission efficiency and soft switching, a novel T-type compensation network for DWPT is proposed, which maintains a stable output characteristic over a wide misalignment, companied with an inherent current limiting ability under no-load operation. A WPT prototype with a fixed frequency operation based on the T-type compensation network is built. The output power is kept almost stable even though magnetic coupling coefficient varies twice showing the effectiveness of the design method.