Efficient Dynamic Phasor Model of Distributed Photovoltaic Systems

The computational challenge in solving dynamic models of power distribution grids increases with the high penetration of distributed photovoltaic (PV) systems. The existing dynamic models of PV systems are overly detailed and computationally intractable for solving distribution grid dynamics with a large number of distributed PV systems. As IEEE-1547 requires smart PV inverters to support the grid voltage and frequency dynamically, this motivates to develop an accurate and computationally efficient dynamic model of distributed PVs. Therefore, in this work, a dynamic phasor model of smart PV inverters is developed and compared with an existing electromagnetic transient model (detailed model) in terms of accuracy and computational efficiency. The results show a remarkably fast solve time of the proposed dynamic phasor model compared to that of the detailed model (more than 30 times speed up), while sufficiently capturing necessary volt-var, volt-watt, and frequency-watt dynamics during the normal, and voltage ride-through and frequency ride-through events.