Improved deterministic real-time estimation of Maximum Power Point in photovoltaic power systems

Heuristic tracking algorithms are commonly adopted for Maximum Power Point Tracking (MPPT), which generates oscillations around the Maximum Power Point (MPP) of the PV array. Alternative solution using deterministic curve-fitting approach is proposed in this paper to locate the MPP accurately. The non-linear PV curve is approximated by a polynomial equation, of which the coefficients can be identified in real time by using a recursive methodology with variable forgetting factors. This method is named as Recursive Estimation with Variable Forgetting Factor (REVFF). Thus, the tracking accuracy is improved without the perturbation of PV voltage. The proposed system and control scheme are implemented and verified by simulation.