Advances in OpenDSS smart inverter modelling for quasi-static time-series simulations

The fleet of smart distributed energy resource (DER) inverters is expected to grow rapidly as a result of growing DER penetration levels and requirements in interconnection standards/rules such as IEEE Std 1547-2018. Smart inverters have the potential to help to maintain and/or enhance grid safety, reliability and customer affordability. Advanced modelling and analytical capabilities are required from distribution planning tools to understand the full potential of smart inverters. This study presents enhanced smart inverter modelling and simulation features included in a recent release of the open-source distribution system modelling and simulation software suite OpenDSS. The enhanced features include detailed modelling of the inverter capability curve along with significant improvements to the simulation speed and convergence. The enhanced features make it more practical to perform long quasi-static time-series load flow simulations with thousands of time steps on large-scale utility feeder models with up to thousands of autonomously controlled smart inverters. Some of the enhanced speed, convergence and other features are demonstrated on a large-scale real U.S. utility feeder model with >1100 solar photovoltaic systems.