POWER-VOLTAGE AND REACTIVE-VOLTAGE CURVES FOR VOLTAGE STABILITY ANALYSIS ON THE 58 BUS, 330kV NIGERIAN NETWORK.

Voltage instability is an undesirable phenomenon in power system networks, resulting from a system being severely loaded causing a gradual voltage drop which eventually leads to a blackout in the system. It frequently has to do with the power system's reactive power supply. Therefore, it is essential to comprehend the critical loading point in order to make sure the power system operates securely. The study helps identify weak buses and lines that are in the connected buses to determine the best location for mounting compensating devices on the power system's transmission line network. First, a load flow analysis is performed for all of the buses in the test system, they are simulated using NEPLAN software, and the suspected weak buses in the system are found, along with safe loading margins for real and reactive power for both networks. The Newton-Raphson load flow method is used to assess the condition of the network's buses, and the real power against voltage magnitude (P-V) and reactive power against voltage (Q-V) curves which reveals the maximum loadability at each candidate buses. The IEEE 14-Bus and Nigerian National Grid 330kV 58-Bus systems, which served as the study's case studies, were used to assess the recommended approach. Base case and contingency analysis were the two situations that were examined for the two systems listed above. The IEEE 14-Bus system's buses and lines were all stable in the basic scenario. With a reactive loading margin of 74.6MVAr, the 14th bus was discovered to be the most vulnerable bus in the network during the contingency analysis simulation. The loss sensitivity index was calculated for all lines in the IEEE 14-bus network, and it was discovered that lines linking bus 14 had the lowest valuation. During base case simulation for the 330kV 58-Bus Nigerian network, Birnin-Kebbi, Gombe, Makurdi, Yola, Maiduguri, and Jos buses were found to be very close to the lower limit of 0.95 p.u. During contingency simulation, it was discovered that the Maiduguri Bus was the weakest in the network, with a reactive loading margin of 385MVAr. Finally, the loss sensitivity index of the 58-Bus network was evaluated, and Line 15 to 53 was discovered to have the lowest sensitivity index in the network and the ideal position for suitable compensating device installation. According to the research presented in this dissertation, the P-V and Q-V curves are particularly helpful for determining how consistently voltage levels are maintained across a power system network