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Christian Dorst avatar image
Christian Dorst asked

Multiplus II ESS Mode 1 latency and limits

Hi folks,

I just installed a 3-phase ESS Mode 1 with 3 multiplus II 5000-70-50. Since there is a lot of PV installed yet, I decided to connect the PV on AC-Input, and installed an EM24. The installed battery is a pylontech US3000 rack with 2 stacks of 6 battery piles.

I got some error messages about high voltage, but found the information in the tutorial for pylontech batteries about 52V..

The reason I'm writing is the discharge behavior of the multiplus. The latency ist very high (serveral seconds for a load of about 2000W). I searched for a reason, and found a 400W per second limit referenced to the grid codes. Is there any posibility to adjust this value?

The software is up to date (2623474 on the multiplus und 2.54 on the venusGX).

Best regards

Christian

ESS
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Alexandra avatar image Alexandra ♦ commented ·

@Christian Dorst

What component is generating the high voltage alarm?

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Christian Dorst avatar image Christian Dorst Alexandra ♦ commented ·

The alarm comes from the pylontech BMS, but as I mentioned above, I don't see this as a large problem, more like a little bit annoying.. I found comments for this here:

https://community.victronenergy.com/questions/46633/ess-system-pylontech-battery-alarm-high-voltage-al.html

and here:

https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom


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3 Answers
Christian Dorst avatar image
Christian Dorst answered ·

the problem I have is mentioned here for Mode 2 & 3:

https://www.victronenergy.com/live/ess:ess_mode_2_and_3


"5. Response times and ramp speed

There are multiple factors that determine the response time to a (digital-) command to feed in:

  1. Latency and communication speed of all components in the communication chain: ModbusTCP or MQTT, GX Device, MK3 microprocessor, ESS Assistant, internal communication in the Multi itself.
  2. Rate limiting imposed by the used Country Grid code. Code “Other” has no rate limiting, Code “Europe” allows installer configurable rate limiting, many other codes have fixed a powerup ramp up.
  3. Hard coded rate limiting in the inverter/charger firmware: as per ESS version 162 it is set to 400W per second. The reason for this rate limiter is that without that there are regulation problems (overloads and such) when the mains is weak (long cables and such resulting in a relatively high impedance). More information on that here, as well as in the main ESS manual."


I got these 400W/sec in Mode 1 which is way to slow IMHO.



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rainerb avatar image rainerb commented ·

There seems to be other (known?) issues for the slow response speed in an ESS system with several grid meters. See this discussion:

https://community.victronenergy.com/questions/51697/victron-ess-et112-slow-response.html?childToView=51929#comment-51929


Regards

Rainer


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Christian Dorst avatar image Christian Dorst rainerb commented ·

Thanks Rainer, that's excactly what I see here too.

Sunny greetings

Christian

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jacola avatar image jacola Christian Dorst commented ·

Hi guys, i have exactly the same problems. very high latency, and 52V pylontech high voltage alarms.

In my case i have rapidly changing loads - big irrigation pumps, which, once connected, draw 11kwh distributed over all phases.
obviously i want to cover those peaks with my ESS. The absolute worst is that those pumps go on and off (whenever set pressure is reached they go off, then on again).
a 400W/s slow rate makes the system pretty much unusable .. if the pumps come up for 10 seconds, then off 10 seconds, about 3.6kw per phase, i need 9 seconds after they switch on until i have the power covered, for 1 second, then i overproduce 9 seconds .. completely useless.
Other than setting the ESS to constantly produce 10kw while the pumps run (and give the idle times for free to the grid) .. anyone has an idea ?

Johannes


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mucwendel avatar image
mucwendel answered ·

Any news about the slow battery charge/discharge response?

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baxter avatar image
baxter answered ·

Hi, any news on that? Our mains in Austria is not weak so more than 400W/sec would be fine to avoid any unnecessary grid consumption and feed in because of slow responses on load changes

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