An Extremum Seeking Algorithm Based on Square Wave for Three-Dimensional Wireless Power Transfer System to Achieve Maximum Power Transmission

This article proposes an extremum seeking algorithm (ESA) based on a square wave, which provides an alternative method to the dynamic maximum power transmission problem of the three-dimensional (3-D) wireless power transfer (WPT) system. The proposed method uses a square wave signal instead of the sinusoidal signal as the detection signal, which is simpler to implement in the discrete control system. By simultaneously detecting two azimuths of the 3-D WPT system, the detection time of the maximum power transmission point is reduced. The convergence of the ESA based on square wave is verified according to the mathematical model of the system. Finally, an experimental prototype is set up to verify the correction and effectiveness of the ESA based on square wave. The experimental results manifest that the system can reach the maximum power transmission point within 150 ms after the load position varies.