Phasor and Simplified Average Models of Two-Stage Single-Phase PV System

The computational challenge in solving dynamic models of power distribution grids increases with high penetration of distributed photovoltaic (PV) systems. IEEE-1547 requires smart PV inverters to provide dynamic volt-var and volt-watt support functions, which motivates solving dynamics of large distribution grids with multiple distributed PVs. The existing dynamic models of PV systems are overly detailed and computationally intractable for solving distribution grid dynamics with a large number of distributed PVs. In this work, a simplified average model and a phasor-based model of a two-stage single-phase smart PV system are developed and compared with the existing average and detailed models in literature. The results show remarkably fast performance from the proposed phasor-based and simplified average models of PVs, while sufficiently capturing necessary volt-var and volt-watt dynamics.