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.