High-Performance Adaptive Perturb and Observe MPPT Technique for Photovoltaic-Based Microgrids

TLDR

Solar PV has grown rapidly, becoming a key distributed generator in low‑voltage grids, and its integration into microgrids demands efficient MPPT controllers, yet conventional perturb‑and‑observe methods suffer from oscillations, trade‑offs, and reliance on preset constants. This study proposes a modified perturb‑and‑observe MPPT technique for PV systems. The technique is demonstrated through an experimental implementation on a PV‑based microgrid. The experimental results show adaptive tracking, elimination of steady‑state oscillations, and removal of predefined constants, validating the generic design core across varying irradiance levels.

Abstract

Solar photovoltaic (PV) energy has witnessed double-digit growth in the past decade. The penetration of PV systems as distributed generators in low-voltage grids has also seen significant attention. In addition, the need for higher overall grid efficiency and reliability has boosted the interest in the microgrid concept. High-efficiency PV-based microgrids require maximum power point tracking (MPPT) controllers to maximize the harvested energy due to the nonlinearity in PV module characteristics. Perturb and observe (P&O) techniques, although thoroughly investigated in previous research, still suffer from several disadvantages, such as sustained oscillation around the MPP, fast tracking versus oscillation tradeoffs, and user predefined constants. In this paper, a modified P&O MPPT technique, applicable for PV systems, is presented. The proposed technique achieves: first, adaptive tracking; second, no steady-state oscillations around the MPP; and lastly, no need for predefined system-dependent constants, hence provides a generic design core. A design example is presented by experimental implementation of the proposed technique. Practical results for the implemented setup at different irradiance levels are illustrated to validate the proposed technique.