Optimal Allocation of Dynamic Var Sources in Power Systems Using Two-Stage Strategy

The reactive power compensation effect of dynamic var sources in power grid largely depends on the installation sites and capacities. A two-stage method is proposed to apply to optimal allocation of dynamic var sources. In the first stage, the index system is established to evaluate candidate nodes for dynamic var source placement, including minimum capacity of dynamic var source, V-Q sensitivity and static voltage stability margin. On this basis, the weights of candidate nodes are obtained using analytic hierarchy process (AHP). In the second stage, several nodes with larger weights are selected for dynamic var source placement according to the weight of each candidate node. Within the nodes selected above, the moth-flame optimization algorithm is used to obtain the most economical configuration scheme considering short-term voltage stability. The effectiveness of the proposed method is demonstrated by a real regional power grid in provincial system.