Concerning Maximum Power Point Tracking for Photovoltaic Optimization Using Ripple-Based Extremum Seeking Control

This paper highlights key contributions in extremum seeking (ES) control and ripple correlation control (RCC). Maximum power point tracking (MPPT) utilizing the 120-Hz inherent inverter ripple is shown to be developed in the early 1980s. Even though that specific MPPT development did not explicitly mention ES control, the analysis presented there shows otherwise. RCC stability and operating properties are also addressed where the fundamental difference between RCC and popular ES control methods is the perturbation source. Since RCC utilizes inherent switching ripple in power electronics, the high ripple frequency leads to fast RCC convergence.