Dynamic voltage stability of distribution system with a high penetration of rooftop PV units

Photovoltaic (PV) power is an environmentally friendly source of energy, which is quite convenient for integration into distribution systems in form of rooftop PV units. However, a high penetration level of PV units is needed to supply required energy for a considerable part of system loads. The impact of this high PV power penetration on the system stability needs to be assessed. Considering the importance of voltage part of stability in distribution systems, this paper investigates the dynamic voltage stability of a distribution system with high PV penetration. For this aim, short-term voltage response of the network is assessed for the case of sudden loss of PV power generation due to moving clouds or tripping of PV units during faults. These scenarios are studied for IEEE 37-bus test system with dynamic load and PV models.