A novel LC-N resonant topology for strongly coupled wireless power transfer system

Wireless power transmission (WPT) excitation systems can solve the problems of mechanical wear and unreliability of carbon brushes and slip rings in electrically excited synchronous motors (EESMs). Usually, wireless excitation devices have a close transmission distance and operate under a strongly coupled state, which leads to the increase of current harmonic elements in the system and a decrease in efficiency. Meanwhile, the stable operation of the EESMs requires the WPT system to provide a constant output current. This paper proposes an LC-N WPT resonant topology to solve the problem of the high harmonic contents of current under strongly coupled, which improves system efficiency. Firstly, the working theory of the proposed topology and the conditions for achieving constant output current are analyzed. Then, a simulation model and experimental platform are established to verify the high harmonic filtering characteristics of the LC-N topology. The results demonstrate the advantages of the LC-N topology.