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Title: Draft Electric Rule 21 Test Protocols for Advanced Inverter Functions

Technical Report ·
DOI:https://doi.org/10.2172/1762017· OSTI ID:1762017
 [1];  [1];  [2];  [2];  [2];  [3];  [4];  [5];  [6]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Underwriters Laboratories (United States)
  3. Electric Power Research Inst. (EPRI), Palo Alto, CA (United States)
  4. Xanthus Consulting (United States)
  5. SunSpec Alliance, San Jose, CA (United States)
  6. Loggerware (United States)

Disclaimer: The following document includes draft certification protocols and should not be viewed as a consensus-based performance standard. Distributed energy resources (DERs), such as photovoltaic (PV) systems, when deployed in a large scale, are capable of significantly influencing the operation of bulk and local power systems. Looking to the future, European and American stakeholders are working on standards to make it possible to manage the potentially complex interactions between DER and the power system. One of the jurisdictions considering modifications to the DER interconnection requirements is California. To determine what changes could improve electric grid reliability and allow greater penetrations of renewable energy, the California Public Utilities Commission (CPUC) and the California Energy Commission (CEC), in conjunction with consultant Frances Cleveland, convened the Smart Inverter Working Group (SIWG) in January 2013. The SIWG--composed of state agencies, utility engineers, national laboratories, manufacturers, trade associations, and advocacy groups--provided the CPUC a set of recommendations in early 2014 1 . The recommendations included specific advanced DER functions and interoperability requirements, along with a proposed timeline, for California to add new capabilities to grid-interconnected DER. On August 18, 2014 the three California Investor-Owned Utilities (IOUs)--Pacific Gas and Electric Company (PG&E), Southern California Edison Company (SCE) and San Diego Gas & Electric Company (SDG&E)--drafted a Advice Letter filing to the CPUC setting forth revisions to Electric Tariff Rule 21 to conform to the seven recommendations made by the Working Group 2 . After a comment period, the CPUC issued an update to the IOU recommendations 3 . At the time of this publication, there was no final legal ruling on the CPUC Rulemaking (R.) 11-09-011 ("Order Instituting Rulemaking on the Commission's Own Motion to improve distribution level interconnection rules and regulations for certain classes of electric generators and electric storage resources"). In the U.S., Nationally Recognized Test Laboratories (NRTLs) independently verify products to safety and functional standards. PV inverters are certified to Underwriters Laboratories (UL) Standard 1741 4 . However, new advanced inverter functions described in the SIWG and IOU proposals are not included in this standard, so there is a critical need to develop test protocols for these functions in preparation of a positive ruling by the CPUC. Through a California Solar Initiative Grant, Sandia National Laboratories (Sandia or SNL), Underwriters Laboratories (UL), Electric Power Research Institute, Inc. (EPRI), Xanthus Consulting, SunSpec Alliance, Loggerware, and utility and PV inverter manufacturers have collaborated to draft this certification protocol for the Rule 21 SIWG Phase 1 advanced inverter functions. This report also includes test procedures for Phase 2 and Phase 3 functions that will be demonstrated later in the CSI4 project. This collaborative effort was performed in close junction with the UL 1741 Standards Technical Panel (STP) working group. This document represents a snapshot of the draft testing protocols at the time of publication and not a consensus certification protocol for advanced inverters. 1 California Public Utilities Commission, "Recommendations for Updating the Technical Requirements for Inverters in Distributed Energy Resources, Smart Inverter Working Group Recommendations," Filed 7 Feb 2014. 2 J.J. Newlander, R.G. Litteneker, S.W. Walter, M. Dwyer, Joint motion of Pacific Gas and Electric Company (U 39 E), Southern California Edison Company (U 338 E) and San Diego Gas & Electric Company (U 902 E) regarding implementation of smart inverter functionalities, Rulemaking 11-09-011 Advice Letter, 18 July, 2014. 3 J.T. Sullivan, CPUC Rulemaking 11-09-011 Agenda ID #13460, 13 Nov, 2014. 4 Underwriters Laboratories Std. 1741 Ed. 2, "Inverters, Converters, Controllers and Interconnection System Equipment for use with Distributed Energy Resources," 2010.

Research Organization:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Organization:
USDOE Office of Electricity (OE), Advanced Grid Research & Development. Power Systems Engineering Research
DOE Contract Number:
AC04-94AL85000
OSTI ID:
1762017
Report Number(s):
SAND-2014-20590; 674202
Country of Publication:
United States
Language:
English