Analysis and Control of Inductive Contactless Power Transfer System with Secondary Regulator

The Inductive Contactless Power Transfer (ICPT) system can be used in maglev trains for its no friction, immunity to ice and dirt and other merits. By keeping the primary coil current constant, the output voltage can be regulated by the onboard DC/DC regulator. In this paper, the non-monotonic relationship between the regulator's DC/DC voltage ratio and the output voltage or current are shown. The efficiency characteristics are analyzed. A DC/DC ratio limiter is provided to make the output control stable. Efficiency optimization design suggestions are also provided for both constant voltage output control and constant current output control.