Power system transient stability analysis in the case of high-penetration photovoltaics (part 2)

In the previous paper [1], transient stability of power system with high-penetration photovoltaic (PV) was assessed by simulation analysis of IEEE 9-bus power system model with infinite bus. Through the simulation analysis, it was concluded that the transient stability is better in the case with PV without low-voltage ride-through (LVRT) capability installed. This is because the synchronous generator output after the fault clearing can be enlarged due to the loss of power supply from PV. However, as the power system model used for the simulation has infinite bus, the transient analysis was performed under the situation where power supply-demand balance in the power system can be maintained in spite of the disconnection of a huge amount of PV. In this work, the potential impact of significant PV penetration on the transient stability is assessed by the simulation analyses performed for the power system models with and without infinite bus,in which the effects of various conditions, such as variety of power sources (inverter or rotational machine), existence of LVRT capability, reconnection of PV to the grid and two types of faults in the power system, on the transient stability are investigated.