Investigating the steady state stability of the Nigerian 48- bus systems using facts devices

Abstract

With the ongoing expansions and growth of the electric utility industry, including deregulation in Nigeria, numerous changes characterized by additional generating stations, increase in transmission lines and loads are experienced thereby pushing the transmission systems closer to their stability and thermal limits and hence, causing the transfer of reactive power during steady state operating conditions to constitute a major problem of voltage instability. Flexible ac transmission systems (FACTS) controllers have been utilized for finding solutions to various power system stability control issues such as voltage instability. This paper uses Static Synchronous Series Compensator (SSSC) and Thyristor Controlled Series Compensator (TCSC) to investigate the voltage magnitude profile, active and reactive power losses of the Nigerian 48-bus power system network for steady state stability enhancement using power system analysis toolbox (PSAT) in MATLAB environment. Optimal location of the FACTS devices was achieved through the computation of the voltage stability sensitivity factors (VSSF) for all the buses after continuation power flow (CPF) was carried out. Simulation results obtained without and with the FACTS devices revealed that the two FACTS devices especially TCSC has the capability to raise voltage profile of the buses and mitigate against power losses.

Keywords: CPF, FACTS, MATLAB, Optimal location, PSAT, SSSC, stability, TCSC, VSSF