The rising electricity consumption, rapid fossil fuel depletion, and a higher shift to the use of renewable or green energy resources have increased the need to integrate renewable and distributed energy resources (DERs), like solar photovoltaic (PV) energy to power the utility grids. In this study, the researchers have determined the effect of PV inverters to offer reactive power to an adapted IEEE 13-node distribution network. Power flow analyses were conducted on MATLAB/Simulink for various reactive power modes of PV inverters to show the effect of the reactive power on the regulation of grid voltage, reduced the total harmonic distortion (THD), and maintain the power factor so as to improve the ability of the system to handle power. The result shows that using a 400 KW PV system in a bus (675) led to a reduction in the power generated from the generator by 11%, and the use of the reactive power capability of PV inverters on-site improved the voltage profile significantly. as well, reduced the voltage THD by 27.09% when injected with reactive power, reduce the current THD by 77.39% When absorbing reactive power, and improved the power factor on-site.

Distributed generation (DG) based on a photovoltaic system (PV) connected to a power system is a very promising solution to meet the present demand for energy and to reap the advantages of using clean energy. With the exponential increase in the deployment of distributed energy sources based on renewable energy, the reactive power drawn from the grid has increased dramatically compared to the active power. This affects the quality of the power from the network. Reactive power is usually required to regulate the power factor and the grid voltage so as to improve the ability of the system to handle power. In this paper, the reactive power capability of a PV inverter connected to the grid was determined using the MATLAB/Simulink program. The amount of active power and reactive power injected into the network were independently controlled by their reference values. The study showed the effectiveness of the effect of injection/absorption of reactive power on raising/lowering voltage and improving power quality by reducing the Total harmonic distortion of the voltage and current under different operating conditions.