Renewable Energy Integration for Voltage Stability and Power Transfer Optimisation in Nigeria’s 330 kV Transmission Network
Imo Edwin Nkan *
Department of Electrical and Electronic Engineering, Akwa Ibom State University, Nigeria.
Paul Edet Okon
Department of Electrical and Electronic Engineering, Akwa Ibom State University, Nigeria.
Anyanime Tim Umoette
Department of Electrical and Electronic Engineering, Akwa Ibom State University, Nigeria.
Iniobong Edifon Abasi-Obot
Department of Electrical and Electronic Engineering, Akwa Ibom State University, Nigeria.
Dominic David Ekpo
Department of Mechanical Engineering, Akwa Ibom State University, Nigeria.
Archibong Archibong Etim
Department of Electrical/Electronic Engineering, Cross River State University, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Nigeria’s 330 kV transmission network continues to face critical operational challenges, including voltage instability, excessive transmission losses, limited power transfer capability, and inadequate infrastructure expansion, all of which undermine reliable electricity delivery and constrain economic growth. Increasing electricity demand driven by urbanisation, industrialisation, and population growth further exacerbates these challenges, necessitating innovative and sustainable approaches to transmission system enhancement. This study investigates the integration of renewable energy resources, particularly solar photovoltaic (PV) generation, as a strategic solution for improving voltage stability and optimising power transfer performance in Nigeria’s high-voltage transmission network. A transmission network model was developed using a 5-bus power system configuration in MATLAB/Simulink, while steady-state system performance was evaluated using the Newton-Raphson load flow algorithm. The methodology involved modelling transmission buses, generators, transmission line parameters, and integrating a grid-connected 3 MW solar PV system into the network to assess its impact on voltage profiles, power losses, and overall transmission performance. Solar PV system design considerations included irradiance characteristics, module configurations, voltage-current relationships, and power generation capabilities under varying environmental operating conditions. Simulation results demonstrated substantial improvements following renewable energy integration. Voltage magnitudes at buses previously operating below acceptable stability limits significantly improved, with bus voltages increasing from 0.8302 pu, 0.6338 pu, 0.5344 pu, and 0.6581 pu to 0.9902 pu, 1.0001 pu, 1.0100 pu, and 0.9947 pu, respectively, thereby restoring network voltage levels within recommended operational standards. Furthermore, active power losses decreased remarkably from 3.05 MW to 0.65 MW, representing a 78.33% reduction in transmission losses. The integrated solar PV system also demonstrated stable generation capability, producing approximately 3 MW under standard irradiance conditions while enhancing overall system power availability and operational resilience. The findings establish renewable energy integration as a technically viable and economically sustainable approach for strengthening Nigeria’s transmission infrastructure. Beyond improving voltage stability and minimising transmission losses, renewable energy deployment enhances grid reliability, increases power transfer capability, and supports long-term energy sustainability objectives. The study provides valuable insights for power system planners, policymakers, and energy sector stakeholders seeking practical pathways toward modernising Nigeria’s electricity transmission network and accelerating the transition toward cleaner and more resilient power systems.
Keywords: Transmission network, renewable energy integration, power transfer optimisation, solar photovoltaic systems, voltage stability, active power losses, transmission losses, power transfer capability