A Method to Estimate Power System Voltage Stability Margins Using Time-Series From Dynamic Simulations With Sequential Load Perturbations

In this paper, a methodology to assess power system voltage stability margins from time-series data is presented. The proposed method obtains time-series from dynamic simulations subject to sequential load changes that are then used as an input to a voltage stability estimation method. After a contingency is applied, load perturbations aim to move the system through different loading levels. This approach allows estimating voltage stability margins from time-series without any information or numerical quantities of the mathematical model of the system other than the simulation's output. This is useful for dynamic security assessment systems that only have transient simulators for their workflows and still require to estimate the voltage stability margins. The proposed method is used to quantify the severity of the contingencies using a three-layer index. The proposed approach is illustrated using a simple two-bus system and then tested using time-domain simulations of the Nordic-44 Bus test system.