Emergency voltage and reactive power control using reduction of variables considering effectiveness against voltage stability

This paper proposes flexible centralized control against voltage instability phenomenon by meta-heuristics considering reduction of control variables. Meta-heuristics can search solution flexibly. However, it has a possibility that meta-heuristics can not search solution within inequality constraints due to stochastic character. In addition, a longer solving time is required. In the proposed method, the disadvantages of meta-heuristics are improved by reduction of variables. The criterion for reduction of variables is based on effective degree against dealing with voltage instability. Moreover, voltage stability index called L-index is used to evaluate the effectiveness of variables against dealing with voltage instability. Particle swarm optimization (PSO) of meta-heuristics is applied to centralized voltage and reactive power control (Volt / Var Control : VVC). Single line outage contingencies at two point (N-2 contingencies) are considered, then the effectiveness of the proposed method is verified by simulation using IEEE 30 bus system.