Research on optimal allocation of reactive power compensators in substation

An optimal method on allocation of reactive power compensators in substations is proposed in this paper. Equivalent circuit of 110kV substation is built up, which can model load capacity, short circuit capacity, transformer, motor in load, and power factor. Power load is modeled with composite load containing motor and constant Z load. Firstly the capacity of shunt capacitor is determined by the demand to make power factors of entirely substation equal to 1. Secondly the capacity of dynamic var source such as STAT COM or SVC is determined by the demand to prevent transient voltage collapse under faults. The capacities of reactive power compensators on different system conditions are analyzed which can be referred by power system planners and operators.