In this paper, a proposed efficient solution for an important power quality problem focused on harmonic distortion in the source current is introduced by using Shunt Active Power Filter (SAPF) controlled by the sinusoidal source current control strategy which is based on the instantaneous active and reactive power theory (Sinusoidal PQ-theory). As a part of this controller, there is PI-Controller which enhances the APF controller performance when tuning its proportional and integral gains. The gains of the PI-Controller are optimized in this article based on an effective metaheuristic optimization algorithm known as Mayfly Optimization Algorithm (MOA), and its effectiveness is clear when compared with other algorithms such as Particle Swarm Optimization (PSO), Artificial Hummingbird Algorithm (AHA) and Archimedes Optimization Algorithm (AOA). The performance of the optimized controller is evaluated under load variation and distorted source voltage conditions. The results obtained using MATLAB/SIMULINK prove the ability of the MOA to get the optimal PI-Controller gains which lead to enhancement of the APF controller performance to reduce the total harmonic distortion in the drawing source current with minimum and acceptable values according to (IEEE-519) harmonics standard.

the present paper investigates the effect of penetration of photovoltaic generation (PVGs) systems on the transient and small signal stability. Recently interest in photovoltaic (PV) power generation systems is increasing rapidly and the installation of large PV systems or large groups of PV systems that are interconnected with the power system grid is accelerating despite their high cost and low efficiency due to environmental issues and depletions of fossil fuels. Photovoltaic generators (PVGs) have significant impacts on the existing power systems, these impacts may be either positively or negatively depending on many factors such as PVGs location, size and inverter characteristics. The eigenvalue analysis and the transient analysis of the system are done without any PVGs penetration and with PVGs penetration and then the results are compared. The investigation is applied on IEEE-39 bus test system. The stability analysis is carried out using simulation program of power system analysis tool box (PSAT).