Reactive power optimization considering dynamic reactive power reserves

Traditional reactive power optimization may result in conflicts between power system economic operation and voltage stability. The amount of dynamic reactive power reserves is used as a measure of voltage stability of power system. The effective generator reactive power reserves are calculated to obtain the dynamic reactive power reserves of each voltage control area and the maximum variations in generation under contingency are taken as the required minimal reactive power reserves of each area in this paper. The dynamic reactive power reserves are introduced into the reactive power optimization model as one of multiple objective functions and constraints in order to enhance voltage stability of power system and reduce active power losses while maintaining voltage stability of each area. Numerical tests with IEEE 118-bus system and Liaoning power grid show that the proposed model and method are effective.