Investigation of transient stability of a power network with solar-PV generation: Impact of loading level & control strategy

This paper presents a transient stability investigation with solar-PV generation. In this study solar-PV generation is represented by an aggregated solar-PV model, which is an efficient analytical startegy to investigate transient stability of a power system. The study was conducted using the IEEE 3-machine 9-bus test system in DIgSILENT Power Factory. In this study, two solar-photovoltaic (PV) integration scenarios are considered. First, traditional synchronous generators (SGs) are connected to the grid and then the critical clearing time (CCT) are determined after creating faults at various locations in the network. Second, the traditional SGs are replaced by the aggregated solar-PV system with similar capacity, and then CCT is calculated in order to accurately investigate and quantify the impact of the solar-PV generation. From the simulation studies, it has been found that integration of the solar-PV into the power system have a beneficial impact on transient stability, especially when the solar-PV systems are partially loaded and operated at the voltage control mode. Aggregated representation of the solar- PV generation would not be a realistic representation, as the individual solar-PV system response would not act on a single busbar as represented in this study using an aggregated model. Therefore, future studies are directed towards developing a more accurate solar-PV model to represent the aggregated effect from distributed solar-PV generation.