If you wouldn't mind Peter, I'd like to see this discussion stay on the list. I'd be interested to learn more about the actual anti-islanding features of inverters. What you've described seems to just cover the voltage and frequency windows that the inverter will grid tie to. I was always under the impression (perhaps false) that there were additional software controls to prevent anti-islanding to another inverter. Bill Brooks seems to know more about UL1741 test procedures.
R. Walters r...@solarray.com Solar Engineer On Jul 19, 2011, at 10:04 AM, Peter Parrish wrote: > I need to give a group of California educators the simplified explanation of > inverter anti-islanding. I know the full details are quite complicated and > have evolved a bit over the past few years, but would the following be an > acceptable short explanation? > > *** Please contact me off-list with comments & edits. Thanks. *** > > This is an excerpt from a longer discussion about designing and installing > grid-tied > "Inverter anti-islanding is a requirement of the NEC and the Underwriter’s > Laboratory test procedures. A somewhat over-simplified version of > “anti-islanding” says that if the grid voltage goes out of the range of 216 > to 264 Vac or if the grid frequency goes out of the range 59.9 to 60.1 Hz, > the inverter must shut down within one cycle (1/60th of a second). Once in > this shutdown mode, the grid must come back into compliance (both frequency > and voltage) for 5 continuous minutes before the inverter may turn on again. > This is pretty “ho-hum”. However, two of our laboratory sessions involve > building a real, grid-connected PV system. So when our students go to turn > on their system for the first time, they get to experience the > “anti-islanding” function first hand." > > Peter T. Parrish, Ph.D., President > California Solar Engineering, Inc. > 820 Cynthia Ave., Los Angeles, CA 90065 > CA Lic. 854779, NABCEP Cert. 031806-26 > peter.parr...@calsolareng.com > Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 > > > > > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
