Influence of distributed generation on distribution system voltage stability

Interconnected operation of distributed generation (DG) will become the future trend. This paper studies the voltage stability of distribution network with DGs. According to different network interfaces and operating modes, DGs are classified into four different node types. The processing methods in power flow calculation are also analyzed in this paper. Then voltage stability condition of distribution network is derived out based on the power flow solution. According to four types of DGs, simulations and analysis of the impact on the voltage stability index are con ducted. Simulation results show that the voltage stability is reduced by accessing PV-type DGs, and the quantity of PV-type DGs should be limited. Additionally, the voltage stability of distribution network is improved by accessing PQ-type DGs on different location and capacity.