Preliminary investigation on effect of PV generation on oscillation modes of power system

Capacity of grid connected photovoltaic (PV) power has increased significantly over the recent years in China, a significant number of large-scale PV plants have been put into operation, such as Golmud (300MW) and Long-yang Gorge (320MW) in Qinghai province. These PV plants are always geographically far from load centers and connected to relatively weak transmission networks. Whether these large PV plants will have an impact on the oscillation modes of power system? If yes, what is the impact? They are all still open questions and worthy of further investigation. In this paper, firstly, typical structures of PV plant integration system are designed, including chain and ring structures. Secondly, based on the typical structures, two influencing factors, namely PV penetration level and electrical distance of PV plant from power system, are chosen to investigate the impact of PV plant on power system oscillation modes. The analysis results based on DIgSILENT PowerFactory software have been listed and compared under the two system topology structures.