A Simple Active Power Control for a High-Power Wireless Power Transmission System Considering Coil Misalignment and Its Design Method

A series-series compensated capacitors topology of the wireless power transmission (WPT) system has a characteristic of increasing active power at coil misalignment when controlled using the conventional secondary dc-link voltage control. This results in a larger total capacity of the primary and secondary sides' converters. To cope with these problems, this paper proposes a simple constant secondary active power control method, where the secondary dc-link voltage is regulated according to the onboard active power rating and secondary current. The effectiveness of the control method is verified by 100 W experimental systems. The numerical simulation that considers the harmonic components is established to be compared and justified by the experimental results, which is then used to design the capacity of a 300 kW WPT system assuming actual railway vehicle application. By the proposed method, the design criteria of the rating voltage and current of the primary and secondary sides' components can be determined.