<div dir="ltr">Utilities have used and continue to use this method of control for their own generators, except they refer to it as Droop Control. In addition to Frequency/Watt response Voltage/VAR response is also used. <div><a href="https://en.wikipedia.org/wiki/Droop_speed_control">https://en.wikipedia.org/wiki/Droop_speed_control</a></div><div><br><div>Building inverters that mimic the behaviour of spinning generators is a great development as some jurisdictions now require, for example, ride-through capability when brown-outs occur, rather than the older requirement for inverters to simply turn off when voltage or frequency dropped below certain limits, which just exacerbated brown-outs. Essentially an inverter can be programmed to have "inertia" just like a big spinning generator.<div>Larger grid-interactive inverters have done this for a while, with very complex settings, but we are now seeing smaller residential and commercial inverters with similar capabilities. </div><div>This industry keeps evolving and improving, which is great for keeping us on our toes and I find it very exciting.<br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><span><p style="padding:5px 0px;color:rgb(36,105,100);font-size:14px;font-family:soleil,Helvetica,Arial,sans-serif;line-height:1.4rem;letter-spacing:0.04rem;font-weight:lighter!important"><img src="https://viridianenergy.ca/sites/all/themes/viridian/emails/signature-line.png" style="color:rgb(0,0,0);font-family:"Times New Roman";font-size:medium;letter-spacing:normal"><br style="color:rgb(0,0,0);font-family:"Times New Roman";font-size:medium;letter-spacing:normal"></p><p style="padding:5px 0px;color:rgb(36,105,100);font-size:14px;font-family:soleil,Helvetica,Arial,sans-serif;line-height:1.4rem;letter-spacing:0.04rem;font-weight:lighter!important"><strong><span style="font-size:1.2rem">Eric Smiley,</span></strong> Project Manager<br><a href="mailto:eric@vecoop.ca" style="color:rgb(255,255,255)" target="_blank"><span style="color:rgb(0,168,133)">eric@vecoop.ca</span></a><br><a href="tel:+12507036004" style="color:rgb(255,255,255)" target="_blank"><span style="color:rgb(36,105,100)">T: 250.703.6004</span></a><br><a href="tel:+18883860116" style="color:rgb(255,255,255)" target="_blank"><span style="color:rgb(36,105,100)">T: 888.386.0116</span></a><br><strong><a href="https://viridianenergy.ca/" style="color:rgb(255,255,255)" target="_blank"><span style="color:rgb(0,168,133)">VIRIDIANENERGY.CA</span></a><strong></strong></strong></p><p style="padding:5px 0px;color:rgb(36,105,100);font-size:14px;font-family:soleil,Helvetica,Arial,sans-serif;line-height:1.4rem;letter-spacing:0.04rem;font-weight:lighter!important"><strong style="color:rgb(0,0,0);font-family:"Times New Roman";font-size:medium;letter-spacing:normal"><strong><a href="https://viridianenergy.ca/" target="_blank"><img src="https://viridianenergy.ca/sites/all/themes/viridian/emails/signature-footer.png"></a></strong></strong><br></p></span></div></div></div></div></div></div></div><br></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, 2 Dec 2022 at 07:08, Windy Dankoff via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>Dear Mike,<div><br></div><div>As co-author of upcoming book "The Handbook of Solar Water Pumping", we have expanded its definition to include micro and national grid-tied systems in which pumping is synchronized with power availability from PV. I had known about frequency-based load control for microgrids (from an SMA-based microgrid I toured in Israel). I had no idea it was a happening system on public grids until I read your response here. I love how it requires no communication lines or digital signals. It's a "natural" and logical concept from the old days of spinning generators under varying load.</div><div><br></div><div>I see your PG&E reference, but is there also a reference text you can recommend that I can use in the book as a universal explanation of how this works?  It can be SMA documentation, or other ref.  You can reply here if it's useful to the list, and/or contact me off-line.</div><div><br></div><div>Thanks!  – Windy<br><div><br><blockquote type="cite"><div>On Dec 1, 2022, at 5:47 PM, <a href="mailto:re-wrenches-request@lists.re-wrenches.org" target="_blank">re-wrenches-request@lists.re-wrenches.org</a> wrote:</div><br><div><div style="font-family:ArialMT;font-size:14px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;margin:0px"><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif;color:rgb(127,127,127)"><b>From:<span> </span></b></span><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif">Harry Mahon <<a href="mailto:Michael.Mahon@sma-america.com" style="color:blue;text-decoration:underline" target="_blank">Michael.Mahon@sma-america.com</a>><br></span></div><div style="font-family:ArialMT;font-size:14px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;margin:0px"><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif;color:rgb(127,127,127)"><b>Subject:<span> </span></b></span><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif"><b>Re: [RE-wrenches] AC Coupling Standard?</b><br></span></div><div style="font-family:ArialMT;font-size:14px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;margin:0px"><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif;color:rgb(127,127,127)"><b>Date:<span> </span></b></span><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif">December 1, 2022 at 5:47:18 PM MST<br></span></div><div style="font-family:ArialMT;font-size:14px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;margin:0px"><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif;color:rgb(127,127,127)"><b>To:<span> </span></b></span><span style="font-family:-webkit-system-font,"Helvetica Neue",Helvetica,sans-serif">RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org" style="color:blue;text-decoration:underline" target="_blank">re-wrenches@lists.re-wrenches.org</a>><br></span></div><br style="font-family:ArialMT;font-size:14px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><br style="font-family:ArialMT;font-size:14px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><div style="font-family:ArialMT;font-size:14px;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif"><span style="font-size:12pt">Definitely it is possible for newer grid-interactive inverters.  However, for grid-tied operation, the utility that runs the grid sets the rules (and sets the setpoints as it were), and it can be confusing....<u></u><u></u></span></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif">Looking at PG&E’s Rule 21 tarriff (submitted Aug 12, 2022, effective Nov 4, 2022) Freq-Watt reuirements are:<u></u><u></u></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif">“When system frequency exceeds 60.036 Hz, the active power output produced by the Smart Inverter shall be reduced by 50% of real power nameplate rating per hertz (5% of real power nameplate rating reduction per 0.1 hertz)”<u></u><u></u></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif">Bottom of Sheet 207 of :<span> </span><a href="https://www.pge.com/tariffs/assets/pdf/tariffbook/ELEC_RULES_21.pdf" style="color:blue;text-decoration:underline" target="_blank">https://www.pge.com/tariffs/assets/pdf/tariffbook/ELEC_RULES_21.pdf</a><u></u><u></u></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif">So a 5kW inverter needs to ramp at 2.5kW/Hz.  But if it is only producing 2.5kW, it has to be at 0W at 61.036Hz.....<u></u><u></u></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif"><u></u> <u></u></div><div style="margin:0in;font-size:11pt;font-family:Calibri,sans-serif">Mike</div></div></div></blockquote></div><br></div></div>_______________________________________________<br>
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