Performance validation of global MPPT for efficient power extraction through PV system under complex partial shading effects

Introduction

Photovoltaic (PV) energy has attracted global attention due to the effects of climate change, decaying fossil fuels, and rising electricity costs. With the implementation of new PV technologies, its installation cost has significantly decreased, making it a more affordable option for energy generation. In real climate, PV arrays can be shaded by nearby trees, buildings, clouds, and other obstacles, leading to non-uniform irradiance distribution known as partial shading condition (PSC). When PSC occurs, the PV array displays multiple power point peaks, including various local maximum power points (LMPPs) and a single global maximum power point (GMPP). This results in PV modules being unable to achieve their optimal operating point consistently and affects its overall performance efficiency¹. Thus, the efficient maximum power point technique (MPPT) is crucial for enhancing solar energy utilization under dynamic climate profiles. PV energy provides an alternate solution to Pakistan’s energy crisis, which includes a growing energy shortage, limited oil reserves, and inconsistent utility grid infrastructure. In addition to standalone PV applications, the integration of solar PV with grid-based virtual power plants (VPP) has been explored as a means to optimize energy scheduling and enhance grid reliability². Such approaches, when combined with advanced MPPT techniques, can contribute to more stable and efficient energy distribution. A significant proportion of oil is imported from oil-rich nations, leading to substantial expenditure on oil importation. It not only resolves the energy crisis but also has the ability to create jobs, promote local manufacturing, and enhance economic growth³. Pakistan’s diverse topography and climate profiles create favorable conditions for solar energy installation. Many regions across the country enjoy abundant sunlight yearly, with an average irradiance of 6.5 kW/m²⁴.

In literature, various traditional MPPT algorithms such as perturb and observe (PO)⁵, adapted perturb and observe (APO)⁶, incremental conductance (IC)⁷, modified incremental conductance (MIC)⁸, improved incremental conductance (IIC)⁹, and constant voltage technique (CVT)¹⁰ are utilized to track optimal point of PV systems; however, these algorithms are not suitable under PSCs and dynamic weather conditions^11,12. Although these methods have simplified computations and easy installation, they may fall towards the LMPPs and exhibit overshoots and steady-state oscillations (SSOs) but are...