Enhancement of the Small-Signal Stability of Nigerian 330 kV Transmission Network using Static Synchronous Compensator

Aims: To analyze the small-signal stability of the Nigerian 330 kV transmission system and the performance of Static Synchronous Compensator (STATCOM) controller in enhancing the system’s stability upon incorporation

Methodology: Newton-Raphson method of solution was adopted for the power flow analysis and Eigenvalues method was employed for small-signal stability analysis. Simulation was used for the analysis and was carried out on Power System Analysis Toolbox (PSAT) software version 2.1.11 in MATLAB environment.

Results: The voltage magnitudes from power flow results of Nigerian transmission network for five critical buses, buses Damaturu, Gombe, Jalingo, Maiduguri and Yola gave 0.8529, 0.8529 0.8299, 0.8249 and 0.83433 p.u respectively. While the corresponding magnitudes after incorporating STATCOM controller were 1.02, 0.9768, 0.9568, 1.05, 0.9607 p.u. Furthermore, the eigenvalues result for small-signal stability contains seven positive eigenvalues. After incorporating STATCOM controller, all positive eigenvalues changed to negative.

Conclusion: The Nigerian transmission network is weak with voltage limits violation but the incorporation of STATCOM was able to bring the voltage magnitudes of all buses within limits. Also, the network is small-signal unstable, however, STATCOM controller was able to enhance the stability when incorporated.