Automatic control to compensate misalignments of a wireless power system

This work presents a control procedure for tracking the tuning frequency of a wireless power transfer system. The inductive link tracks the maximum possible power delivered to the load by dynamically tuning the power source frequency, compensating misalignments or movements between the transmitter and receiver coils or any variations of the magnetic coupling factor. Initially, the equivalent circuit of the inductive link is characterized in order to identify the maximum power delivered to the load when both frequency of the power source and magnetic coupling factor k of the coils are varying. Thus, the trajectory of the maximum delivered power to the load is mapped and fitted in the plane of variations of both k and frequency with a polynomial of first degree. Also, the system monitors phase and magnitude of the input current of the inductive link, combining the data with the first degree polynomial and estimates the magnetic coupling coefficient between the transmitter and receiver coils. Finally, the frequency of the power source can be adjusted by a firmware according to the updated k, tracking the maximum power delivered to the load and closing the loop.