Daily Volt/VAr control in distribution system in presence of Distributed generators considering voltage security constraints

Today in modern distribution systems to suit a variety of operating conditions and also installed a large number of distributed generation, in order to have an appropriate safety margin to voltage, the voltage security constraint must also to be added in the objective function of voltage and reactive power control, along with other objective functions. This paper proposed multiobjective voltage and reactive power control in the presence of DG in the distribution network from the perspective of improving voltage security. Thus, in the formulation of the objective function of this problem minimization of total electrical energy losses, minimization of voltages deviations and maximization of voltage stability have been examined. To achieve the proposed purposes, should be take optimum dispatch schedules for on-load tap changer (OLTC) settings and all shunt capacitors switching on the network. Therefore, to reduce the volume of calculations and the number of switching, daily load curves by optimization algorithm is classified. Furthermore, an evolutionary algorithm using the GA algorithm is proposed to solve the Security based volt/var control in the distribution system in the presence of distributed generators. Finally, IEEE 33-bus is considered as case study to demonstrate the effectiveness of the proposed method. With the results of simulation been this fact received that besides improving voltage stability, total electrical energy losses and voltages deviations are also improved.