Re: [EVDL] 250V high line effects on solar EVs

[Willie via EV]

On 9/4/21 9:34 AM, Mark Hanson via EV wrote:

Thanks Lee
My extension cord power company said they won’t do anything unless it hits 7% 
over 240V and since I’m near the substation , I see it 250-252V so the folks at 
the end of the line miles away aren’t too low.  Most local pole peg 
transformers don’t have taps anymore to save $$ so it’s up to the customer to 
put bucking transformers in on sensitive equipment.  Most appliances are power 
loads with the wattage the same as they draw less current (no change in meter 
billing) at a high line condition but solar inverters must run higher than the 
line to push back current.  They use the switching power supply universal 
85-264V operational range so always operating near the high end. I told Enphase 
to bump up their voltage to be mid range operational but they won’t do it due 
to increased cost for higher voltage components.  I can copy the club. I don’t 
have a problem with gmail although sometimes the settings block Outlook email 
and have to reset to allow secondary devices.


Here are some musings that some may find relevant.  Or, maybe not.

When I started putting in PV, I noticed my line voltage wast about 245.  
I had a 15kva transformer which, in this rural area, is normal for not 
all electric house.  All electric houses tend to get 25kwa.  I've never 
seen a 50kva for a "normal" residence.


As I install more and more PV, I noted my voltage climbing. Sometimes, 
some of my micro inverters would shut down presumably when they saw 
265v.  Some of this high voltage was due to marginal branch circuits 
which I worked to alleviate.  I found when my meter voltage reached 
about 255, I had inverters shutting down somewhere.


Consulting my utility: they put a voltage monitor in my meter for a few 
days and found it, indeed, high.  I suggested to them that I would be 
happy with more like 230v which would have given me more "head room" at 
inverters.  They claimed to no longer installing multi-tap transformers 
which could have, at least temporarily, alleviated the problem.  I ended 
up having them replacing, at my cost, the 15kva with a 37.5kva.  I was 
walking on thin ice because my PV agreement called for me to produce no 
more that 10kw.  I eventually accepted an agreement that allowed me to 
produce 50kw.


I am now pushing the capacity of the 37.5kva; I see delivered power as 
high as 30kw.


In case it is not obvious, producing power raises voltage just a using 
power reduces.  My understanding of that and transformer capacities 
developed only as my PV projects proceeded.



___
Address messages to ev@lists.evdl.org
No other addresses in TO and CC fields
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
ARCHIVE: http://www.evdl.org/archive/
LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org

Re: [EVDL] 250V high line effects on solar EVs

[Mark Hanson via EV]

Thanks Lee
My extension cord power company said they won’t do anything unless it hits 7% 
over 240V and since I’m near the substation , I see it 250-252V so the folks at 
the end of the line miles away aren’t too low.  Most local pole peg 
transformers don’t have taps anymore to save $$ so it’s up to the customer to 
put bucking transformers in on sensitive equipment.  Most appliances are power 
loads with the wattage the same as they draw less current (no change in meter 
billing) at a high line condition but solar inverters must run higher than the 
line to push back current.  They use the switching power supply universal 
85-264V operational range so always operating near the high end. I told Enphase 
to bump up their voltage to be mid range operational but they won’t do it due 
to increased cost for higher voltage components.  I can copy the club. I don’t 
have a problem with gmail although sometimes the settings block Outlook email 
and have to reset to allow secondary devices. 
Best regards 
Mark

Sent from my iPhone

On Sep 4, 2021, at 1:16 AM, Lee Hart  wrote:

Mark Hanson via EV wrote:
> Hi Cor etc
> I have the same issue, our pole pigs are set to 250V split phase no taps 
> (taps only at local sub station) due to rural feed on an extension cord 
> company (rural coop) so the folks far away get 240ish.  This causes the solar 
> Enphase 64 inverters to hit 264V at 2pm and then pop.  Since Enphase didn’t 
> do a FMEA , I found out from the recorded data, dying on high line after 
> about half of them died. The fix (since the power company refused to change 
> the sun station tap, said they did but didn’t ) is to get two 6.3V toroid 
> core 120V transformers (can not be EI core for idle losses) and put the 
> secondaries out of phase in buck mode in series with each 120V hot side thus 
> reducing the 250V to 237.4V and the inverters no longer drop out at 264V and 
> pop.  My 3 EV charging stations for the Leaf, Bolt and Tesla don’t care since 
> they have wider range switching power supply/chargers in the cars and don’t 
> see over 250V since they’re a load and not a source.

Hi Mark,

I can't post to the EVDL; Earthlink started using Vadesecure last month, and 
the EVDL listserver (and others) won't accept email from it. (grump grump...)

But I wanted to mention I've had exactly the same problem. My line voltage 
tends to be a bit high, and PV pushes it even higher. My Enphase hasn't died 
yet (thankfully), but my Trace Microsine trips off at 126 vac. That prompted me 
to do exactly as you did; I installed a buck/boost transformer to drop the AC 
line voltage a bit so the inverter doesn't trip off.

It's no doubt protecting the Enphase (which I got from you) as well!

Best wishes, and hope you and your family are well.

Lee Hart

-- 
We aren't devoting nearly enough scientific research to find a cure for
the most recent pandemic; contagious stupidity.
   -- paraphrased from Bill Watterson (creator of "Calvin and Hobbes")
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com

-- 
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

___
Address messages to ev@lists.evdl.org
No other addresses in TO and CC fields
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
ARCHIVE: http://www.evdl.org/archive/
LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org