Static and dynamic performance assessment of a grid-connected solar photovoltaic system in a Nigerian 33/11 kV distribution network

In this study, we investigate the impact of a 2.5 MW grid-connected solar photovoltaic generation (SPVG) plant installed at the Nigerian Defence Academy (NDA), Kaduna, on the 33/11 kV NDA distribution feeder network. Nigerian distribution networks experience challenges such as voltage deviations, excessive feeder losses, and inadequate power support relative to load demand. Distributed generation (DG), particularly solar photovoltaic systems, can improve voltage profiles and reduce feeder losses by supplying power close to load centers. The distribution network was modeled using the Power System Analysis Toolbox (PSAT) in the MATLAB/Simulink environment. Static and dynamic analyses were carried out to evaluate the impact of the integrated SPVG on the feeder network. Simulation results show that the 2.5 MW SPVG improved the voltage profile across all buses from values below 0.95 pu to within the permissible operating range of 0.95–1.05 pu. DG integration also improved active and reactive power flow while reducing feeder-level active power losses by 34%–39% and reactive power losses by 52%–57%. Dynamic response analysis revealed improved voltage and current stability with faster settling times following disturbance conditions. Furthermore, sensitivity analysis showed that the 2.5 MW PV penetration level provides the best compromise between voltage improvement and power loss reduction, whereas 5 MW penetration resulted in voltage increase beyond the acceptable 1.05-pu limit. The results demonstrate that integrating solar PV generation into the NDA distribution network enhances voltage stability, improves feeder performance, and reduces localized feeder losses. All simulations were implemented using MATLAB and PSAT.