Contribution of Distributed Generation to Voltage Regulation under Stochastic Attribute of Renewable Energy Resources

This paper concentrates on the contribution of distributed generation (DG) to distribution system voltages. DG is utilized to help to regulate the system voltage profile to lie close to the desired value, i.e. to reduce the voltage variation. With the varieties of dispersed locations, operating modes, and allowable sizes, DG can be properly designed and controlled to be a powerful means of voltage regulation, and work parallel with the existing voltage regulation. However, it is known that DG may cause the voltage fluctuation to the system due to the counter flow and reactive power change. According to the conflict features of DG over system voltages, the contribution of DG to the voltage regulation is obtained by the optimization process. This is carried out simultaneously with the adjustment of voltage regulator setting. Besides, the issue of stochastic attribute of DG is taken into account. Probabilistic load flow (PLF) is employed to cope with this concern. The proposed method has been applied to the IEEE 34-Bus distribution test system. The results show that the proposed method yields a satisfactory voltage regulation while the uncertainty from renewable energy resource is considered.