Characteristics of static voltage stability for distributed generation integrated into power system and its impacts analysis

Static voltage stability of the grid integrating distributed generation (DG) mostly depends on the capacity and control methods of DG. The analytic expression of load voltage regard to the penetration of DG is derived in this paper, and on the basis, the load voltage and the PV characteristic is analyzed under different DG penetrations. Then the impact of the different reactive power control strategies on load PV characteristic is compared. Using the extended line voltage stability index to analyze the static voltage stability of the grid integrating DG, the effects of reactive power control strategies on the line voltage stability index is studied. The results show that constant voltage control is more conducive to enhance the static voltage stability.