The global shift towards renewable energy (RE) sources, driven by climate change and fossil fuel depletion, encounters challenges in integrating intermittent sources like wind and solar power into existing grids. Developing countries, such as Nigeria, with weak grids, face significant limitations on RE penetration. This study focuses on enhancing RE grid integration in Nigeria by strategically deploying Flexible Alternating Current Transmission System (FACTS) devices. Results obtained from the Nigerian grid indicate that FACTS devices, particularly STATCOMs, can extend the penetration limit by 40%, enabling an additional 152 MW of wind energy to be integrated without jeopardizing system stability. Improved voltage profiles and enhanced stability highlight the effectiveness of FACTS devices in facilitating RE integration into weak grids. Thus, developing grids can accommodate more renewable energy without extensive reconfiguration of the power system architecture.

The power systems in developing countries are usually stressed and operated near their stability limits. Consequently, accurate sources of oscillations and their controls can present a challenge. This paper reports a comprehensive study of the oscillations in the Nigerian 48-bus power system. The dominant modes, sensitive locations for faults, and the most responsible generators were identified by modal analysis. Uniquely, the potential for nonlinear modal interaction of these modes was carefully investigated. The low-frequency modes identified are 1 Hz, 1.14 Hz, and 1.37 Hz, and they are associated mainly with the generators at Kainji, Afam, and Delta power stations. The results indicate the existence of inter-area phenomena and nonlinear modal interactions among these modes. Also, the analysis revealed that the generator at the Kainji power station is most affected by the nonlinear interactions.