Investigating the Dynamic Stability of the Nigerian 48-bus Systems for Improved System Performance Using FACTS

With the ever increasing complexity in power systems, there is the need to provide stable, secure, controlled and high quality power most especially in the deregulated power industry as obtains in Nigeria. One of the major disadvantages of network enlargement is the deterioration in the damping torque of the whole system which mitigates against the system in the form of fluctuations and dynamic instability. Flexible AC transmission systems (FACTS) controllers have been utilized for finding solutions to various power system stability control issues. This paper uses Static Synchronous Series Compensator (SSSC) to investigate the system responses under the influence of a three-phase fault for transient stability enhancement. Using commercially available PSAT software in MATLAB environment, the Nigerian 48-bus power system network was modeled with a fault introduced on Bus 33(Geregu Sub-Station) and SSSC installed on line 21-28. Optimal location of SSSC on Bus 21(Jos Transmission Station) was achieved through the computation of voltage stability sensitivity factors for all the buses after Continuation Power Flow (CPF) was carried out. Simulation results obtained with and without SSSC revealed that with SSSC, appreciable damping of power system oscillation and enhancement of voltage profile for power system dynamic stability was accomplished.