Generalization of the main MPPT methods

The paper demonstrates that the two main non-model based variable step-size Maximum Power Point Tracking (MPPT) algorithms, namely Perturb and Observe and Incremental Conductance are functionally equivalent. This outcome is achieved by establishing general closed-loop controller-plant structure of corresponding methods, allowing to formulate the MPPT problem as a typical stabilization task. The MPPT loop plants are separated into three main components, two of which are similar and the third one is different. The latter component, referred to as "stabilization function estimator", is shown to be the main reason for the performance differences of the discussed methods. Moreover, in case the estimator bandwidth is decoupled from the MPPT loop bandwidth, similar large signal performance may be expected utilizing any of the methods.