Category: Grid Modernization
With the success of California’s renewable energy policies, by 2010 it was anticipated that DER generation
levels would soon exceed the 15% limit imposed by The Institute of Electrical and Electronics Engineers (IEEE) 1547-2003 standard. To address the challenge of overcoming the 15% limitation, California and Underwriters Laboratories (UL) collaborated on the development of the UL 1741 SA standard to define advanced functionality and safety requirements for so-called “smart inverters” that would enable these devices to be installed in far greater density.
This standard was subsequently utilized to support the implementation of the latest revision of California interconnection Rule 21 (CA Rule 21). The smart inverter functions defined in UL 1741 SA enable DER systems to play a role in supporting the stable and reliable operation of the electric grid.
This poster will capture the results of the Smart Inverter Testing component of the SunSpec awarded California Energy Commission EPIC 14-036 project. The objective of this aspect of the project was to construct a smart inverter testing laboratory at University of California San Diego for the direct testing of inverters according to the criteria for the advanced functions set forth in UL 1741 SA and CA Rule 21. Inverters compliant with this new standard were supplied by the manufacturers and tested in the laboratory with controlled testing protocols according to the requirements of the tests. The tests addressed the “Phase 1” set of functions of CA Rule 21.
During the course of this project, the concepts worked out here were incorporated into the national DER standard IEEE 1547-2018. This portends implications for all inverters installed in the U.S. where authorities adopt this standard for communications related to grid connection.
Understanding the test methodology and results related to smart inverters and their ability to support 100% or more deployment of DER assets on the grid holds implications for manufacturers, installers, jurisdiction authorities, energy and regulatory officials.
Tom Tansy– Chairman, SunSpec Alliance