Analysis and control of post regulation of wireless power transfer systems

The steady-state and dynamic characteristics of an open-loop wireless power transfer (WPT) system that uses post regulation are investigated. The steady-state control-to-output curve is non-monotonic, and the Bode diagram varies significantly with the operating point. These characteristics lead to difficulties in closed-loop control. We reviewed two existing methods that are possible to address the closed-loop control problem: 1) operating at the split frequencies; 2) using a primary side current control loop. These two methods cannot fully address the problem or cause other problems such as low efficiency. We proposed an adaptive control method to handle the non-monotonic control-to-output curve. The method is verified by simulation but the parameters need to be further adaptively optimized for higher speed and accuracy.