Reactive power flow optimization in the presence of Secondary Voltage Control

The Hierarchical Voltage Control has recently become an important alternative to the traditional voltage control solutions. This paper deals with the computation of an optimal profile for the pilot bus voltages using different optimization strategies. For this purpose, the mathematical model of the optimization problem was studied considering two issues: i) defining the constraints of the optimization problem in order to fulfill the actual operating condition of the Secondary Voltage Control system and ii) finding the proper objective function (OF). For validation, tests were made on the Italian Power grid by using the high level modeling system GAMS.