Kostal Inverter with wrong DC value

Tags: #<Tag:0x00007f616d7e6960> #<Tag:0x00007f616d7e6780>

Hi, I use the kostal binding

I was thinking that the channel “CHANNEL_DEVICE_LOCAL_DC_POWER” is more or less an aggregate over the channels:

  • CHANNEL_DEVICE_LOCAL_PVSTRING_1_POWER
  • CHANNEL_DEVICE_LOCAL_PVSTRING_2_POWER
  • CHANNEL_DEVICE_LOCAL_PVSTRING_3_POWER

But its values are far off from what is possible and makes sense:

In my installation, I only use strings 1 and 2, therefore, dc3 is empty / null. As you can see, the value do not sum up to what is show for the PV Generator (here 3,4kW) while the sum is around 5,9kW.

Can anyone explain how to read the values or what I might be doing wrong? I wouldnt mind to build an aggregate virtual Item to reflect the sum, but I would like to know what that CHANNEL_DEVICE_LOCAL_DC_POWER is there for and how to read that value. :slight_smile:

Thanks in advance.

I dont use Kostal myself. I use SMA. But the principal looks the same:

The voltage you see should be the sum of the panels connected to that specific string. Depending on the sun (ofcouse) voltage as well as current will rise.

How many panels are you having on string 1 ? And whats their specification?

I have a two string system as well… This is how it looks right now:
String 1 - 8 300watt panels:

String 2 - 14 300watt panels:

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Your observation matches perfectly my expectation.

I also have a two string system (east / west orientation).

  • String1 (east) has 21 panels connected to it
  • String2 (west) has 9 panels connected to it
  • String3 (unconnected) has 0 panels

Sometimes, the values seem to work like currently, and sometimes they dont. I dont understand why… :frowning:

PS: I didnt polish the UI yet, first want to get it protocolling everything right to influx for historical reasons :slight_smile:

It might be, that loading the connected battery influences the value… Does it? I just noticed that the battery is now charged 100% and is not used as there is enough power from the PV.

I have a battery connected as well (LG Resu 10H) :slight_smile: It does not have any influence on the production of the panels. Only on the consumption side you migt see some small votage changes depending on the consumption.

Your values seem to be correct to me… I´m not sure which ones you dont feel is correct?

As I mentioned, in the second screen shot all values are right. But have a look in the first:

image

You see

  • the sum of the PV generator in the very top: 3369,51 W
  • the power of the first string (DC Eingang 1 Ost): 5623,38 W
  • the power of the first string (DC Eingang 1 West): 242,07 W

The total sum here would be 5.865,45 W but for some reason it only shows 3369,51 W. So I wonder what the difference is and where it does come from. Could that be the consumption for loading the battery? What else could it be?

AHHH sorry… I was focusing on the individual values and didnt even notice the sum at top left :smiley:
Where does this value come from? (its in your sitemap setting)…

I (finally) see where your getting at…
I believe you´re reading wrong channel on your kostal inverter… There should be a total production in watts…
But if there is not, there is another option for you…
Group the two watts items into a new item, and use the SUM in your new group like this:

.items

Group:Number:SUM       gTotalEnergy     "Total Energy producing [%s kWh]"           <Energy>

And then use the gTotalEnergy item in your sitemap…

Job done :smiley:

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Yes I will use this grouping function for the right aggregation. Great idea. Still, I wonder what this value stands for. Maybe there is someone that can explain how the value is calculated and what it really means. :slight_smile:

Thanks @Kim_Andersen

Optimized the syntax to:

Group:Number:Energy:SUM Photovoltaik_DC_Leistung "PV Leistung [%d %unit%]"

So no worries in handling the unit measurement. :slight_smile:

You´re welcome…

About your wondering… The Kostal binding (doc) should tell you… I dont know, but I may have an idea…
Could it be the full production minus your household consumption?
Or maybe full production minus the battery charging? (also a consumption).
Or maybe all three together?

Yes, if your items contains unit, then thats the way to use it… My items doesnt, as the unit isnt transfered though modbus, as far as I know. I havnt tried if I could add it myself… I just do the hard dump work in the items insted :smiley:

About your wondering… The Kostal binding (doc) should tell you… I dont know, but I may have an idea…
Could it be the full production minus your household consumption?
Or maybe full production minus the battery charging? (also a consumption).
Or maybe all three together?

Yes, that is also my current assumption, but I would love to get a clear statement on this. So my guess is:

Result = FullProduction – BatteryCharing + BatteryInjection

Anyone that could verify this?

Sorry I cant help much as I do not have a Kostal. I use SMA and LG battery…
But I have a question

You said it shows wrong DC value. But isnt the Production and BatteryInjection suppose to be AC and not DC ??

IMHO: Production and Battery is DC (direct), not AC (alternating). :slight_smile:

Correct. But what exactly do you want this to be.

DC og AC measurings?

I already mentioned my expectation in the initial posting:

I was thinking that the channel “CHANNEL_DEVICE_LOCAL_DC_POWER” is more or less an aggregate over the channels:

  • CHANNEL_DEVICE_LOCAL_PVSTRING_1_POWER
  • CHANNEL_DEVICE_LOCAL_PVSTRING_2_POWER
  • CHANNEL_DEVICE_LOCAL_PVSTRING_3_POWER

Sorry but I got confused beacuse I thought you were looking for the sum of the power consumption of the household…

Does your Kostal support 3 string (Solar panels series) ? In that case you may be right, that the CHANNEL_DEVICE_LOCAL_DC_POWER is the sum in power (Watt) of the three strings.

Yes we have 3 possible strings. But only 2 are connected.

The total consumption is calculated correctly. But the total production is not. Thats the whole point of my question. :slight_smile:

I´m very sorry. I totally lost track, even with my own posts :unamused:

You screenshot in first post is production of the strings.
The value in the upper left corner has to be something else, and not production. I doubt its has anything to do with production at all. Isnt the channel explained somewhere?

I cannot follow you. Please go over my first two posts and you will understand my problem. thanks.