I now have the task of installing a 3rd array, and am choosing a controller for it.
I currently have 2 evergreen arrays, one on a tristar MPPT60, other on a classic 200. The Tristar kicks the Classic into the mud whenever there is anything less than pure sun. A little haze, 15% performance. Clouds, it sleeps. a break in the clouds, it wakes up, till the sun fades out. sunrise, sunset, it's a half hour later/earlier than the Tristar.
Is there a solution ? any troubleshooting I can try ? Since this week is going to be cloudy, when I'm not tending the generator, I'll try playing with the legacy modes, fixed MPPT voltage, anything to get some harvest that I told my wife we'd have.
The classic array is 2Kw, tristar is 3Kw, so I'd expect to see the same ratio of output. In full sun they track pretty well, as I'd expect.
Firmware:
- Classic Rev: 1849
- Network Rev: 1839
When I used to use my Classics for solar, and first bought our XW-MPPT60's to integrate with our new (at the time) XW Power System, I had the same problem. The XW's pretty much stomped on the Classic during cloudy conditions. I switched the Classic to Dynamic Mode and got a significant improvement, as well as more hours online during the day. The only problem is that the Classic's Dynamic Mode is a little slow on tracking when it's sunny with scattered clouds that block out the sun intermittent. The regular Solar Mode works better on sunny days (or at least did for me).
I'd try Dynamic Tracking and see what you get. The Classic doesn't seem to unload the array on Dynamic like it does on Solar Mode every few minutes. I remember that it used to slowly vary the Vmp to find where it got maximum power and then sort of "lock in" on that. It worked pretty good here.
Mike, what is your battery voltage supposed to be ? I am seeing something like 62.8 volts battery V on
the Local App screen. What is the target voltage of the Classic ? You will need to go to the MNGP screen
under CHARGE---T-Comp---View and see what that is supposed to be.
If the Classic is seeing battery voltage at or above the temperature compensated target voltage,
it won't try to charge at that time. It may also be that the MS is bringing that battery voltage
up to that point ?
AND, what is your Voc of the PV array into the Morningstar ? They may be different.
Also check the LIMITS screen to make sure the MAX temp-comp'd battery voltage is
not limiting that charge voltage. It's pretty high as I see on the screen.
If all is good in that case, then you may want to try either dynamic mode or Legacy P&O mode.
I would try Legacy P&O mode before Dynamic tracking but if the PV input voltage and Voc
is too low, SOLAR may not be the best for this condition.
Please report back as to what you find.
boB
Quote from: boB on October 20, 2014, 08:10:35 PM
If all is good in that case, then you may want to try either dynamic mode or Legacy P&O mode.
boB, as long as we're on the subject, what is supposed to be the difference between the Legacy P&O and Dynamic? I tried both and couldn't really see that they did much different from one another. I did try a wind turbine once with both too, and the Classic did a pretty good job of tracking the turbine on Dynamic. Not so good on Legacy P&O. But with solar panels I couldn't see much difference between them.
From earlier Threads, Mike's battery is NiFe, which needs HIGH Absorb voltages, believe that the TS runs about 90-ish Vmp string and the Classic 200 runs string Vmp of about 130 V (Mike specs String Voc at 110 V for the TS and 160 for the Cl 200).
Believe that the PV array for the Classic looks SE, ...
Some info here:
http://midniteforum.com/index.php?topic=2014.0
To me, the configurations are not very similar and makes direct comparison difficult and perhaps not fair.
EDIT: What was the time if day when the snapshot of each CC's performance was taken?
And guess that there was no shading, on either array, other than clouds (?). What is the azimuth bearing of each array?
FWIW, Vic
Quote from: Vic on October 20, 2014, 11:49:54 PM
.....http://midniteforum.com/index.php?topic=2014.0
To me, the configurations are not very similar and makes direct comparison difficult and perhaps not fair...
The cells are evergreen, just the arrangements in the panels and array sizes differ. So, the power-light ratio should be very close.
If MPPT works on one array. it should work on the other. Or even if one controller wastes 50w in heat, that still doesn't cover the wide variation of output powers. The strings in each array all match each other closely, so I've discounted that as an issue.
My settings
absorb 66.7V 45 minutes.
I have tweaked the meter on the classic, to closely match the Tristar readings
(Battery Voltage offset -0.1V) and only when many amps are flowing, do the meters drift apart.
QuoteMNGP screen under CHARGE---T-Comp---View and see what that is supposed to be.
I'll look at that tomorrow. but for now, Local app shows this at
Compensation: 66.7 V
Quote from: mike90045 on October 21, 2014, 12:58:00 AM
Quote from: Vic on October 20, 2014, 11:49:54 PM
.....http://midniteforum.com/index.php?topic=2014.0
To me, the configurations are not very similar and makes direct comparison difficult and perhaps not fair...
The cells are evergreen, just the arrangements in the panels and array sizes differ. So, the power-light ratio should be very close.
If MPPT works on one array. it should work on the other. Or even if one controller wastes 50w in heat, that still doesn't cover the wide variation of output powers. The strings in each array all match each other closely, so I've discounted that as an issue.
My settings
absorb 66.7V 45 minutes.
I have tweaked the meter on the classic, to closely match the Tristar readings
(Battery Voltage offset -0.1V) and only when many amps are flowing, do the meters drift apart.
QuoteMNGP screen under CHARGE---T-Comp---View and see what that is supposed to be.
I'll look at that tomorrow. but for now, Local app shows this at Compensation: 66.7 V
Attached - sunny AM,
Tristar 73% of PV nameplate
Classic 71% of PV nameplate So with great sun, these track pretty well, but it's less than perfect conditions that the classic looses it.
But this 2nd screen shot, shows the Classic with 145V input 0w output, while the tristar array is still in shadow and not lit up yet, but it's charging the batteries, a bit anyway.
Hi Mike,
The pics are a bit small ...
On the second screen shot, is the TS in Absorb??
Thanks, Vic
Not being boots on the ground, I would suggest swapping the arrays to the other controller to ensure the wiring is not being flaky. It would possibly throw some light on the problem and should be fairly simple to accomplish.
If the arrays are not exactly the same orientation and type you will not be doing a fair comparison as pointed out by another poster. Swapping the controllers may give a better idea what is going on.
Just a thought from the P-nut gallery.
Tom
Quote from: Vic on October 21, 2014, 10:25:14 AM
On the second screen shot, is the TS in Absorb??
No, that's early AM, it's in MPPT which is too short of a label to appear behind the local app window.
As to swapping the arrays, I can put the 130VOC array on to the classic 200, but I can/won't put the 160VOC array on the 150V tristar. Since the melted buss bar in the ePanel incident, I've been keeping an eye and IR thermometer on all the connections, and none seem to be flakey.
Changing modes this AM. Solar = 0 watts Legacy P/O gives me about 35w, and trying to play with UsetVOC%, I can't figure on where to set the % on the local app? Going back to Solar, still gives me 0w
And 15 minutes later, it's up to 45W, while the tristar is at 133w (Solar is still 0)
some more screen shots.
P&O vs Solar vs Tristar & arrays (left array is 2kw/Classic, right is 3kw/Tristar)
I'm still working on getting the images small enough to be uploaded, but still readable.
I also noticed that Legacy P&O and Dynamic modes give better low light performance than Solar mode does. Only drawback is that Legacy and Dynamic have slower tracking. I used Legacy P&O with a setting of 12% and had great performance on cloudy days, but poorer performance on fully sunny days.
The MPPT algorithm in the Classics solar mode is excellent for full sunny days, but not cloudy days.
Quote from: mike90045 on October 21, 2014, 11:22:35 AM
As to swapping the arrays, I can put the 130VOC array on to the classic 200, but I can/won't put the 160VOC array on the 150V tristar.
Ok, just changing the 3Kw array over to the Classic what does the power output look like?
dgd
Quote from: phxmark on October 21, 2014, 02:59:07 PM
I also noticed that Legacy P&O and Dynamic modes give better low light performance than Solar mode does. I
The MPPT algorithm in the Classics solar mode is excellent for full sunny days, but not cloudy days.
A few posts have said something similar but I have never seen this on my C150 running in solar mode. Low light/cloudy performance is excellent and when I tried P&O/Dynamic there was no noticeable improvement.
My C250 is different, it suffers the
dropping input voltage to just above battery voltage and staying there bug that Vic first pointed out some time ago.
Solar mode will not work on it but Legacy P&O is good.
dgd
Quotechanging the 3Kw array over to the Classic what does the power output look like?
That will happen next week when we hope to have some sun.
QuoteAnd 15 minutes later, it's up to 45W, while the tristar is at 133w
Arent we talking about stuff in the noise floor. I wouldnt call that thrashing.
Mike, if you want to try PV U-Set % I would set it to 76% because this is what I calculate (from your pic)
that value to be from the MS screen. That's what it was doing based on Voc = 102V and Vmppt = 76V
I couldn't tell what the Voc was on the Classic when I saw the 1400 or so watts at 116V input but
did see 145V at 0 watts which would be at or close to its Voc at least at that time of the day.
That would be 80%. Doesn't seem that far off but you can try that.
Here is another thing to try when you think the 200 is putting out too low of power compared to the MS.
When the Classic is putting out some power, from the MNGP main status screen, press the soft-left key
(upper-left key) to reduce the PV input voltage. Press the upper-right key (soft-right key) to increase
the PV input voltage. It will change voltage if you just hold it in but you might want to just tap it
for about 1/2 second each press to get it to walk down or up in voltage by little steps.
This will adjust it so that you can play with that tracking and see what it is doing wrong.
I think we can get it to work better but either Legacy, Dynamic or VOC% should work
OK if SOLAR mode isn't going to cut it for this array.
thanks,
boB
Quote from: ChrisOlson on October 20, 2014, 08:27:42 PM
Quote from: boB on October 20, 2014, 08:10:35 PM
If all is good in that case, then you may want to try either dynamic mode or Legacy P&O mode.
boB, as long as we're on the subject, what is supposed to be the difference between the Legacy P&O and Dynamic? I tried both and couldn't really see that they did much different from one another. I did try a wind turbine once with both too, and the Classic did a pretty good job of tracking the turbine on Dynamic. Not so good on Legacy P&O. But with solar panels I couldn't see much difference between them.
Chris, the Dynamic mode is supposed to slowly and continuously track the max power point but the Legacy every once
in a while moves the PV voltage below and then above the last MPPV found. I would not expect either one to harvest
as much energy in a given amount of time compared to wind tracking mode. It will certainly get it semi-close with
a fairly constant wind speed but as we know, wind never sits still.
boB
Quote from: boB on October 22, 2014, 01:09:35 AM
Mike, if you want to try PV U-Set % I would set it to 76% because this is what I calculate (from your pic)
that value to be from the MS screen. That's what it was doing based on Voc = 102V and Vmppt = 76V....
Thanks boB.. Where do I find the place to set
U-Set % Can't find it in the local app.
Hi Mike,
I do not use the Local App ...
Believe that you have a Standard Classis, with an MNGP.
The U-Set % is in the Mode menu, after Dynamic (see Classic Manual - Page 34).
Scroll down to U-Set, and use the Right Soft key to access the U-Set setting page ... you may know this, just FYI. Good Luck, Vic
QuoteThe U-Set % is in the Mode menu, after Dynamic
got it. Bummer to have to do it on the graphic panel. That's a 600' walk to get to it (around a 20' deep ravine)
SOLAR mode is for sure no good in cloudy weather, P/O does work much better in mornings and evenings. I'll have to get
another DC breaker, to wire in as a "jumper" to cross connect the array for testing. Otherwise, I think I would be learning arc welding.
Quote from: mike90045 on October 25, 2014, 12:57:45 AM
QuoteThe U-Set % is in the Mode menu, after Dynamic
got it. Bummer to have to do it on the graphic panel. That's a 600' walk to get to it (around a 20' deep ravine)
SOLAR mode is for sure no good in cloudy weather, P/O does work much better in mornings and evenings. I'll have to get
another DC breaker, to wire in as a "jumper" to cross connect the array for testing. Otherwise, I think I would be learning arc welding.
You should be able to use the Local App to adjust things. Here's what you might want to try...
If you have Wi-Fi at your place and somewhat of a line of sight distance to the controller building, you could
connect up a Wi-Fi Bridge and then you could talk to the Classic over the network.
Might have to place the antenna and bridge in a good location so it can work but then you could have all
sorts of neat communications with that area of your site.
boB
I have been messing with the mode setting on my girlfriend's house Classic and found that the Legacy P&O works quite well. Her panels face a more Southwest direction so they don't get any morning sun. Solar mode stays in resting until there is enough sun hitting the panels to bring it out of resting mode, but the Legacy P&O mode comes out of resting a good 45 minutes before Solar mode. Dynamic mode is somewhere between Solar and Legacy for coming out of resting.
I have Legacy set at 4 minutes at 12% depth.
Quote from: boB on October 26, 2014, 11:56:44 PM.... If you have Wi-Fi at your place and somewhat of a line of sight distance to the controller building, you could connect up a Wi-Fi Bridge and then you could talk to the Classic over the network....
Yep, I've got a 300' wireless connection for the local app. It just does not have all the settings that the on-board graphic panel does. It is pretty handy to be able to change settings, re-start absorb and such remotely.
So, the P&O mode seems to be the best I've found. If I have full sun, I have no problem, it's the gray days that I need every watt squeezed out of those expensive panels & mounts. Arrays are set for winter tilt, summer, a little lost harvest is nothing. Too bad the default algorithm can't manage it. And that nasty sticky stuff on the coin cell holder, got to get in and clean that off, the new controller has a gob of it in there too.
Im just not getting this. The Wh produced by a PV array and charge controller is the area under a bell curve. There is almost neglible area under the margins, so tuning a system for the margins doesnt benefit. Ok so for poor weather. you might want all you can get. The onyl way to tell if any of this turning has any signifcant effect is to compare perfomance curves for identical arrays on identical batterys etc. Theres precious little of this sort of testing around.
Quote from: mike90045 on October 25, 2014, 12:57:45 AM
SOLAR mode is for sure no good in cloudy weather, P/O does work much better in mornings and evenings.
Sorry to disagree but this is just not what I see. Solar mode works fine in cloudy and misty weather AND it generates more PV power in such weather compared to P&O and Dynamic.
Same in early mornings and evenings.
I have eleven Classic 150s at different locations all in solar mode and have spent time with each switching modes in cloudy and misty weather and also near sunset to test which mode is the optimum.
Every time solar mode wins out.
Legacy P&O seems to be able to work better when the PV input voltage is getting closer to the battery voltage usually because the PVs have not been configured to allow a decent voltage headroom for solar mode mppt. Especially in early morning or later afternoon where there may be partial shading issues or just very low angle insolation.
In your case where charging voltages are so high (for NiFe cells) then the PV input voltage may need looking at, perhaps increased, and solar mode revisited.
I agree with Zoneblue's comments. Some more meaningful comparisons with less variables would be nice
dgd
Gotta head to the city for about a week for Dr stuff, Dentist, warranty work on the backup genset and shopping . Things will be set for P&O while I'm gone.
re headroom. Yeah, NiFe batteries need high voltages, which is why array is wired for 160V and Classic 200. That planning seems to be ignored by the classic :P
I'll try to remember to get the spare 200VDC breaker while I'm out too.
Mike. I don't understand about that sticky stuff around the coin cell battery.
We ship a piece of paper to insulate it when shipped but that shouldn't be sticky ?
Those holders are surface mount so shouldn't have any flux on them.
Maybe someone is adding bubble gum to them ?
Quote from: boB on October 29, 2014, 01:56:01 AM
Mike. I don't understand about that sticky stuff around the coin cell battery.
We ship a piece of paper to insulate it when shipped but that shouldn't be sticky ?
Those holders are surface mount so shouldn't have any flux on them.
Maybe someone is adding bubble gum to them ?
Mike has been around the block with sticky stuff around the coin battery:
Quote from: mike90045 on June 15, 2014, 12:21:05 AM
Quote from: Halfcrazy on May 25, 2012, 06:12:43 PM
I would mention there has been a few occasions of the glue holding the "Remove" tag to the battery staying balled up on the battery and causing it not to make connection.
Ryan
I just spent about an hour mucking around with this yesterday, and finally got the glue off the inside of the battery holder. Easy to get the glue off the battery. And of course, got FW upgraded and now a new set of weirdness.
--vtMaps
Yes I have seen that a bunch of times the glue on the remove tag stays behind effectively insulating the battery
Quote from: Halfcrazy on October 30, 2014, 09:46:57 AM
Yes I have seen that a bunch of times the glue on the remove tag stays behind effectively insulating the battery
Oh, well if this is the case, then we must change the piece of paper to real paper immediately !
boB
Quote from: boB on October 30, 2014, 07:47:02 PM
Quote from: Halfcrazy on October 30, 2014, 09:46:57 AM
Yes I have seen that a bunch of times the glue on the remove tag stays behind effectively insulating the battery
Oh, well if this is the case, then we must change the piece of paper to real paper immediately !
boB
Ok?
What do you think this sticky substance is from ?
I will look closer at the stickers tomorrow.