The voltage instability is usually characterized by two mechanisms: unsolvability of the power flow equations and controllability loss. However, the last mechanism has not been considered in the voltage stability probabilistic assessment. The objective of this paper is to present a method to include controllability loss and unsolvability in the voltage stability probabilistic assessment. The proposed method is based on the combination of three techniques: Monte Carlo Simulation Method, Nonlinear Optimal Power Flow and D' Matrix Method. The test results demonstrated that the controllability loss is an important mechanism in the voltage stability probabilistic assessment.
Voltage Stability; Monte Carlo Method; Optimal Power Flow; Composite Reliability; Probabilistic Methods
