The impact of dynamic behaviors of distributed grid-connected photovoltaic system on distribution network transient voltage stability

Due to the increasing capacity of grid-connected photovoltaic systems in distribution networks, its impact on the voltage security can't be ignored. In this paper, based on the voltage stability criterion of maximum transmission power, and considering induction motor voltage response characteristic, the impact of dynamic behaviors of grid-connected photovoltaic systems on transient voltage stability is investigated. Three scenarios have been analyzed, respectively corresponding to three kinds of photovoltaic system's dynamic behaviors: stopping operation after voltage sags, low-voltage ride-through capability and dynamic voltage support. In addition, P-V curve is applied to do theoretical interpretation for the simulation results in the revised IEEE 33-bus distribution network, and it is testified that grid-connected photovoltaic systems equipped with low-voltage ride-through capability can remarkably improve distribution network transient voltage stability, and the effectiveness would be more prominent with the dynamic voltage support of photovoltaic systems.