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Title: Inverter Load Rejection Over-Voltage Testing: SolarCity CRADA Task 1a Final Report

Various interconnection challenges exist when connecting distributed PV into the electrical distribution grid in terms of safety, reliability, and stability of electric power systems. One of the urgent areas for additional research - as identified by inverter manufacturers, installers, and utilities - is the potential for transient over-voltage from PV inverters. In one stage of a cooperative tests were repeated a total of seven times. The maximum over-voltage measured in any test did not exceed 200% of nominal, and typical over-voltage levels were significantly lower. The total voltage duration and the maximum continuous time above each threshold are presented here, as well as the time to disconnect for each test. Finally, we present a brief investigation into the effect of DC input voltage as well as a series of no-load tests. This report describes testing conducted at NREL to determine the duration and magnitude of transient over-voltages created by several commercial PV inverters during load-rejection conditions. For this work, a test plan that is currently under development by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL. Through a cooperative research and development agreement, NREL is working with SolarCity to addressmore » two specific types of transient overvoltage: load rejection overvoltage (LRO) and ground fault overvoltage (GFO). Additional partners in this effort include the Hawaiian Electric Companies, Northern Plains Power Technologies, and the Electric Power Research Institute.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. SolarCity Corporation, San Mateo, CA (United States)
Publication Date:
OSTI Identifier:
1170351
Report Number(s):
NREL/TP--5D00-63510
DOE Contract Number:
AC36-08GO28308
Resource Type:
Technical Report
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 24 POWER TRANSMISSION AND DISTRIBUTION TRANSIENT OVERVOLTAGE; PHOTOVOLTAIC INVERTERS; HARDWARE TESTING; HIGH PENETRATION; SOLARCITY; ESI; PV