ESS + Pylontech + MaxDischargePower is not what I expect?

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Volker asked May 23, '20

ESS + Pylontech + MaxDischargePower is not what I expect?

Hello,

I have a question how to understand the MaxDischargePower in an ESS context.

In my setup I have
- 2 Pylontech US2000 on a Multigrid-II
- not limited the inverter power on the Multigrid
- 50A Discharge Current Limit on the Pylontechs

and with this I see a "MaxDischargePower" on the MQTT service of +/-1949 W where my expectation would be somewhat higher around 2400 W.

It seems that this value is dynamically determined since it changes slightly when polling multiple times.

Thanks for any helping answer - kind regards - Volker

ESS Pylontech

2 |3000

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Answer 1 · 2020-06-14T19:47:20Z

Volker answered · Jun 14, 2020 at 07:47 PM

Hello,

I'm still wondering what experience other people have with this combination: Multiplus(grid) II and 2 Pylontechs US2000 in ESS mode. I never see a max output power above approx. 2000W (42A @ Vbatt), although the discharge current limit is reported to be 50A.

Using firmware v2.54.

Any comment appreciated!

Thanks & kind regards - Volker

2 |3000

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Answer 2 · 2020-06-15T22:18:36Z

markussi answered · Jun 15, 2020 at 10:18 PM

I have the same Problem with 1 Pylontech US2000 and i never seen more than ~850W discharge power.

Kind regards - Markus.

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Answer 3 · 2020-06-16T05:55:46Z

dayandnight answered · Jun 16, 2020 at 05:55 AM

Hello @Volker,

I am not sure that I understand your question or your concern and if I can helpfully with the following info.

I use a 3-phase ESS with 3x Multiplus-II 3000 and 8x USB2000 and based on my AC-loads and status of PV / sunshine I have seen DC current more than 160A discharge. Which is quite close to the max discharge limit in my case of 200A

What are your concerns about? Perhaps this info helps you.

DayAndNight

dc-current-01.jpg (22.3 KiB)

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Answer 4 · 2020-06-16T07:36:52Z

Volker answered · Jun 16, 2020 at 07:36 AM

Hello,

thanks for your reply!

With the data you provided it seems to me that the discharge current is limited by some internal strategy to about 80% - although there is a max discharge current of 25A per US2000 reported in the ESS GUI (in my case thus 50A): in my case the limit is about 1950W (iso 2400) / with 1 US => 850W (iso 1200) and with 8 US => 160A (iso 200A or 9600W).

To me it also seems like this MaxDischargePower is also not a "hard setting limit", but somehow calculated (read out via MQTT):

It would be interesting is someone had more information on this.

Thanks & kind regards - Volker

1592293055004.png (6.5 KiB)

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