Power Flow Control of a 3-D Wireless Power Pick-up

A variable inductor based power flow control method is proposed to regulate the output voltage of a wireless power pick-up. The open circuit voltage variation of the power pick-up is compensated by controlling a magnetic amplifier type inductor in an LCL tuning configuration. The proposed control algorithm directly detects the output voltage of the power pick-up and feedbacks the voltage signal to update the tuning direction truth table discretely. According to the output voltage, the controller determines the direction of the equivalent inductance change of the magnetic amplifier. Both simulation and practical results demonstrated that the proposed control algorithm can effectively maintain the output voltage at a desired value after a short period of transient response. It has been found that the step-size of the variable inductor and sampling time are two key factors governing the control quality. These two parameters were selected based on the tolerance of the output voltage variation and the desired control speed.