Static Voltage Stability Assessment Considering The Impact of Active Distribution Networks

With the distributed photovoltaic (PV) connected to the distribution network, the traditional passive distribution network is transformed into active distribution network (ADN). The need arises to access the impact of ADNs on the voltage stability of transmission networks. This work provides a detailed continuation power flow methodology to evaluate the influence of ADNs on static voltage stability margin of transmission networks. The potential of ADNs to improve the static voltage stability margin is also analysed by adjusting the operating state of PVs. The ADNs can regulate the active and reactive power output of PVs in ADNs to obtain the ADNs operating states which are conducive to the static voltage stability margin of the system. Simulations are carried out on the revised IEEE 9-bus system with three ADNs. The simulating results prove that a larger static voltage stability margin can be obtained by adjusting the photovoltaics output in ADNs.