Stability analysis of the power system with the large penetration ratios of microgrids

With the prevalence of distributed generation (DG) and development of microgrid, tremendous opportunities and challenges are presented. The penetration of microgrids modifies the energy convection in traditional power systems, which has a great impact on the stability of existing systems. In this paper, the influence of the penetration ratio of microgrids on voltage variety and power angle stability of power systems is analyzed. Numerical simulation is carried out with an EPRI 36 bus test system and the allowable maximum penetration ratio is obtained. The factors that affect the penetration ratio are investigated. The studies in this paper provide evidences for the optimal energy matching of DG in microgrids and improvement of the stability and reliability of the power system connected microgrids.