Investigation of photovoltaic grid system under non-uniform irradiance conditions

Abstract

Photovoltaic (PV) systems have recently been recognized as a leading way in the production of renewable electricity. Due to the unpredictable changes in environmental patterns, the amount of solar irradiation and cell operating temperature affect the power generated by the PV system. This paper, therefore, discusses the grid-integrated PV system to extract maximum power from the PV array to supply load requirements and the supply surplus power to the AC grid. The primary design is to have maximum power point tracking (MPPT) of the non-uniformly irradiated PV array, conversion efficiency maximization, and grid synchronization. This paper investigates various MPPT control algorithms using incremental conductance method, which effectively increased the performance and reduced error, hence helped to extract solar array’s power more efficiently. Additionally, other issues of PV grid-connected system such as network stability, power quality, and grid synchronization functions were implemented. The control of the voltage source converter is designed in such a way that PV power generated is synchronous to the grid. This paper also includes a comparative analysis of two MPPT techniques such as incremental conductance (INC) and perturb-and-observe (P&O). Extensive simulation of various controllers has been conducted to achieve enhanced efficient power extraction, grid synchronization and minimal performance loss due to dynamic tracking errors, particularly under fast-changing irradiation in Matlab/Simulink. The overall results favour INC algorithm and meet the required standards.