Smart Inverters Are Getting Smarter
At Four Field Sites, EPRI Demonstrates Standard Grid-Support Functions and Communications
Working on distribution grids in Massachusetts and Michigan, EPRI, DTE Energy, Pepco Holdings, and National Grid successfully demonstrated standardized smart inverter grid-support functions and utility control of inverters using a standard communications protocol. These milestone field tests mark a key step toward enabling grid operators to manage high penetrations of solar photovoltaic (PV) generation, and they are the culmination of a four-year project under the U.S. Department of Energy (DOE) SunShot Initiative to develop, analyze, and test smart inverters in the lab and field.
Prior to this research, there were no standard grid-support functions and communications protocols implemented in inverters. With only manufacturers’ proprietary functions and protocols in place, operators have had a difficult time integrating different PV products into distribution grids. Since 2009, EPRI has been working with DOE, DOE’s Sandia National Laboratories, and the Smart Electric Power Alliance (formerly Solar Electric Power Association) to define and codify a set of functions and protocols with standards organizations, including the International Electrotechnical Commission.
Other insights from the field tests:
- There is significant value in enabling inverters to automatically adjust their own actions in response to local grid parameters, such as voltage and temperature.
- Communication systems between inverters and grid operators should be configured to detect communication loss quickly, restore connection automatically, and apply logical default settings.
- Inverters need to measure grid voltage more accurately for better performance.
- Demonstrations are needed on distribution feeders with higher PV penetrations.
Artwork by Kirk Anderson