Mahdi Barzgar - Electrical Engineering Department AmirKabir University of Technology-Iran
Ali Asghar Khodadoost Arani - Esfahan Electrical Power Distribution Company-Iran
Ahmad Barzgar - South Khorasan Electricity Distribution Company

Voltage stability in distribution power grids is one of the important issues, which has been faintly studied. Due to the different features compared to the transmission systems, the distribution grids require specific studies. They encounter increasing load growth and demand, resulting in approaching the system work points to their stability thresholds; therefore, the undesired voltage collapse phenomenon in the power grids is more likely than before. Accordingly, in this paper, static voltage stability in the distribution grids was studied. In this paper, a new static voltage stability index applicable for online calculation is introduced and using the index and new HSS optimization algorithm, the location and the capacity of distributed generation units are determined to improve the voltage stability in an IEEE ۳۳-bus grid. Simulation results indicate the feasibility and successfulness of the proposed method.