Voltage stability assessment of a power system incorporating FACTS controllers using unique network equivalent

Voltage instability is considered as a main threat to stability, security, and reliability in the modern power systems. Prediction of voltage stability limit of multi-bus system through its two-bus equivalent model is a hot topic of the research in the field of power system operation and control. This paper presents a novel method to assess voltage stability status using a unique two-bus π-network equivalent derived with OPF solution of the actual system at different operating conditions. As the FACTS controllers are now an ineluctable part of power system, this paper considers an SVC and a TCSC in OPF formulation to assess voltage stable states of any interconnected power system in terms of its reduced two-bus integrated π-equivalent system. Simulation results for a practical power system establish that the proposed methodology is highly promising to assess voltage stability in a better way as compared to existing series equivalent model.