Assessment of Voltage Stability of the Nigerian 330 kV Network
Authors: Musa SY, Haruna J
Ability to determine voltage stability before voltage collapse will continue to receive attention of power system operators. Several voltage stability indices to predict closeness of power system to voltage stability boundary have been proposed in literature. In this work, the most appropriate voltage stability indices for the load buses and the branches that connect them are computed for Nigeria’s 33 bus, 39 line, 330 kV network to determine the components of the power system with high probability of voltage collapse. This will serve as a guide for any mitigation action to be taken before system collapse. Findings of this work show that all the buses and branches of the power system are stable with Yola, which is one of the relatively new buses on the network being the most stable while Ikeja West is the most vulnerable to voltage collapse. Similarly, the line between Oshogbo and Jebba transmission station (TS) is the most stable while Ikeja West to Benin line is the closest to point of instability. The buses and branches were ranked according to their closeness to point of instability. The results obtained in this study indicate that the Nigerian power system is entirely stable. Ikeja West bus with the lowest voltage sensitivity index of 0.0313 is the weakest bus hence will be the most likely bus that will collapse. This bus should be considered first in future compensation action that is to be carried out on the network. Transmission line between Ikeja West and Benin is the most loaded.
Affiliations: Department of Electrical and Electronics Engineering, Modibbo Adama University of Technology, Yola, Nigeria
Keywords: Voltage Stability, Voltage Stability Index, Lmn Index, Voltage Collapse, Weakest Bus
Published date: 2020/06/30