Pout_max_daily morningstar variable TS-MPPT-60

svNorthStar

Another M* question, if you please.

The controller, TS MPPT-60, logs this variable internally each day. I have a 490 watt panel system going into 12 Volts. This variable on high output days logs about 4500 W each day. I can't find anywhere that explains what this would represent. The only reference found to it anywhere after many searches is in the M* Modbus manual.

http://www.morningstarcorp.com/en/support/library/TS.APP.Modbus.EN.04.pdf

In this reference it says that it represents "Reports maximum power delivered to the battery today." I'm just trying to understand what it represents and how it is calculated. For some reason, in the help files where the various field variable are defined it is absent. On a good day, I get around 190 Ah into a 12 V system. I would have thought this would have been around 2200 W or so. Anybody ferreted this out yet?

BB.

Re: Pout_max_daily morningstar variable TS-MPPT-60

You really want to confuse us... Don't you.

There are multiple MOD Bus documents (I guess) at MorningStar... The one you linked to did not have anything about the variable... It looks like you need this (older? different?) Mod Bus document:

http://www.morningstarcorp.com/en/support/library/TSMPPT.APP.Modbus.EN.10.2.pdf

I am guessing that this is the PEAK OUTPUT WATTAGE for the present day (until next sunrise?). So, I would guess that yours would be somewhere around:

490 Watts * 0.77 panel+controller typical deratings = 377.3 watts or so

Now, it gets interesting in that you cannot just read the number, there is a scaling involved for all Voltage and Amperage readings:

V_PU hi, V_PU lo
[1,2][0x0000, 0x0001] (V). voltage scaling.
The scaling value for all voltages. The scaling value is defined as:
V_scaling = whole.fraction = [V_PU hi].[V_PU lo]
Example:
V_PU hi = 0x004E = 78
V_PU lo = 0x03A6 = 934
V_PU lo must be shifted by 16 (divided by 2^16) and then added to V_PU hi
V_scaling = 78 + 934/(2^16) = 78.01425

And the Amperage scaling:

I_PU hi, I_PU lo
[3,4][0x0002, 0x0003] (V). current scaling.
The scaling value for all currents. The scaling value is defined as:
I_scaling = whole.fraction = [I_PU hi].[I_PU lo]
See the V_PU scaling example above

Then use that number for the Pout_max_daily:

Pout_max_daily (in Watts) = n·V_PU·I_PU·2^-17

Clear as mud (been many a decade where I did anything more than binary addition/subtraction.

-Bill

svNorthStar

Re: Pout_max_daily morningstar variable TS-MPPT-60

Wow, kind of sorry I asked, I think? So, saying all that, when the controller logs 4200 watts on a day that it also logs 160 Ah into a 12 volt system that means what?
It also logs a watt hour reading, along with a bunch of other stuff that I've been able to figure out. Everything else in this group of variable is either a cumulative daily number, ie, aH per day or a max or min number, ie max battery temp, min battery temp, etc. Just not sure what it's supposed to tell me and can't seem to correlate it to everything else.

BB.

Re: Pout_max_daily morningstar variable TS-MPPT-60

If you do the math correctly, My guess is your system will record (very roughly) 377 watts--Same as watching the watt meter looking for the peak value in the day...

It is not a bad thing to have--It is a handy know your system's peak power on a mixed cloud day... I.e., under full sun, you will log a series of peak output wattage... And if that number declines over time, or drops by 1/2, etc.--Then you know that something is wrong with the wiring/solar panels/etc...

It would be interesting if the peak power could occur during float (for example)--Batteries are full, no reason to have high current from the charger--If they (for example) run a MPPT Scan once every X minutes--And could record the peak the system is cable of even though that day's AH/WH charge controller output would be low (since batteries are full).

-Bill

svNorthStar

Re: Pout_max_daily morningstar variable TS-MPPT-60

BB,
I swear I'm not trying to be dense here, but I still don't get it. I understand the math, etc, but the end result is telling me what? It is in watts and say 3200 watts of what? You said 377 watts output, which is about right, but then is that multiplied by some time factor per day? Like 10 hours X 377 watts = 3770?? I have a feeling this is one of those forest for the trees moments, but I would like to understand.

Below are the screen shots of the two sets of data I get from the controller. The first one, which have been discussing, shows what the controller internally tracks and makes available the next day. The second is a pic of what is available on a real time monitoring basis.
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There appears to be correlation between the Va_max_daily and the pout_max_daily numbers. It doesn't seem to correlate to the Ah's or Wh's numbers.

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This shot shows the continuously variable data that I log and can view and real time.

Probably making something out of nothing here, but I don't see the purpose or what it's supposed to show.

Thanks for your patience and help on this.

BB.

Re: Pout_max_daily morningstar variable TS-MPPT-60

I believe that Poutmaxdaily should be similar the daily maximum value of Vb*va with the peak stored.

I would guess that it actually could be the log of V Pmax (last sweep) (peak over the last 24 hour or last/current sunny period).

Which, in your second screen shot is 427 Watts (not 4,xxx watts).

As far as usefulness--I would use it as a long term Min/Max value to indicate the health of the system... If you see the Daily Max Power to fall by 1/2 on an otherwise sunny day (or over a few days if bad weather), then it would flag there is something possibly wrong with the system (failed panel, failed wiring, etc.).

I am not quite following your time stamps (same time of day at 11:27 AM? Says UTC, so -4-8 hours depending on your time zone--I.e., first thing in AM before sun up?).

If daily log dump (before sun), then the roughly 4,xxx Watt readings would appear to be daily peak as actual power collected would be more variable (and probably much less as you don't get 10 hours of noon time sun per day). So--I still think there is a divide by ~10 (divide by 8?) missing here somewhere....

Anyways--My guesses. I think you know more what is going on here than I and my poor guesswork.

-Bill

svNorthStar

Re: Pout_max_daily morningstar variable TS-MPPT-60

Bill,
Thanks for the help. The timestamp is kind of odd. This is actually kept internally for up to 200 days and the Msview software keeps it as xml data. The program allow you to output it as comma delimited file, which is the format the logger app in Msview uses. Of course, you can then import to a spreadsheet and do whatever. The screenshot I sent is fairly close to my max day. I think the highest momentary current flow I've seen is 35.63 amps and a corresponding input power of 508 watts and output power of 490 watts. The data on the panels is 245 watts in parallel, which I'm actually surprised that we get as much as this says we get out of them. We are much warmer than standard day here at 8 degrees N.

I'm sure there was a reason it was in there and I've been able to find documentation of all the other data that the system generates. This one just confused me. The unit actually generates a a wealth of data that can be logged as frequently as you want and massaged in a spreadsheet to whatever purpose you might need. This one is just an internal data point that it keeps track internally whether you set up a logging system or not....seemingly making it appear to be important???

Thanks again,
Steve

BB.

Re: Pout_max_daily morningstar variable TS-MPPT-60

Regarding current flow, that also depends on battery voltage at that instant in time... 500 Watts into 12.5 vs 14.7 volts will be different.

-Bill

svNorthStar

Re: Pout_max_daily morningstar variable TS-MPPT-60

On the timestamps, that is just the way it comes from the controller. Would have been nice if it were in some standardized format and would have required a lot less playing around with the spreadsheet to make it intelligible. We are UTC-5 here and the time corresponds to about the time we start seeing daylight here. It's getting earlier. I think that triggers the data write in the unit. But, if you cycle the unit it creates another entry. I'm not real clear on what happens to make these entries occur. Back in the modbus manual it talks about NIGHT mode + X hours in several places so I think that has something to do with it. Just looking at the times though, I think this is when it comes out of sleep mode. I've seen it generating current at 6:30 am here.

svNorthStar

Re: Pout_max_daily morningstar variable TS-MPPT-60

Here is the max day that I managed to get a screen print of, I think it is pretty close to all it will do.
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