Evaluation of a HVDC Interconnection to Improve the Voltage Stability of the Nigerian Transmission Network

Abstract

The Nigerian transmission network is prone to outages and low reliability, and both issues are currently impacting the population's quality of life and hindering economic development. This situation is expected to worsen in the future, due to the increase in forecasted demand. This paper assesses the stability of the Nigerian transmission network under existing grid conditions, and determines the impact of High Voltage Direct Current (HVDC) on voltage stability. The PV and QV analysis methods were carried out using the DIgSILENT PowerFactory software package. Two weak buses were identified, and an HVDC model was built and integrated into the existing network at these locations. The results demonstrated that the HVDC interconnector positively impacts system stability by improving the voltage profile and the reactive power margin (RPM).