Voltage Stability-Based Identification of Critical Buses in Power Networks Using an Improved Index

Inappropriate identification of critical buses for placement of power electronic devices which improve the post disturbance recovery voltages in power system, results in voltage instability which brings great challenges to monitoring of power transmission and expansion planning. This paper developed a Line-Voltage Stability Index (L-VSI) with Equilibrium Optimizer (EO) to identify the critical buses and to obtain the global optimal solutions for optimum location of the power electronic devices in electrical power system. The optimal L-VSI with EO algorithm was developed using the weighted sum of normalized value of the system line loss and generator bus voltage based on the oscillation damping ratio. Simulation was done in MATLAB R2023a. The approach was evaluated with data sets of Nigerian 31- bus systems. The effectiveness of the approach in terms of generator damping ratio and total active power loss was compared with other stability indices. The results showed that the optimal L-VSI provided better results when compared with the results obtained from other stability indices during contingency. Thus, this study would help the Independent System Operators (ISO) to identify weak buses with high impact of voltage instability in electrical power system