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motylu avatar image

Multiplus-II grid protections and feed-in control in 3-phase configuration

Hello guys,

I am from Czech Republic and planning to use 3x MultiPlus-II 48/3000 in 3-phase configuration and DC coupled system with PV array (2 strings, 2 MPPTs) and Pylontech batteries.

Of course I will set grid code to "Europe (EN50549-1:2019)" and there are several options for over/undervoltage and over/underfrequency protections, conditions for normal connect and reconnect after trip, controlling power according to frequency and voltage and also option for use Aux 1 input as feed-in disable signal. Setting of all protection is clear for me but our electric distributor have several requirements for connecting "micro-generators" (PVE with P < 10 kW) to the grid, so I have two questions about grid code functionalities especially in 3-phase mode:

  1. If the condition for activating grid protection on one Multi is met and therefore AC input of Multi must be disconnected from the grid, is then automatically disconnected all Multis from the grid?
  2. I want to use disable feed-in using Aux 1, because our distributor must be able to reduce power feeding to grid (for these micro-generator only two states: 100% and 0% feed-in). My question is how disable feed-in function is realized in practise on Multis and whether I must used Aux 1 on all Multis (for example with 3-pole relay, each pole for each Aux 1) or if is sufficient to use Aux 1 only on one Multi (probably on phase L1) and feed-in will be automatically disabled in general for all Multis?


Thank you very much for your answers.

Multiplus-II3 phasegrid code
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

1. All will disconnect from the grid.

2. The signal is only needed at the master (L1).

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motylu avatar image
motylu answered ·

Thank you very much for your quick response. Function is as I expected, so it will be easy to implement!

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motylu avatar image
motylu answered ·

How to set up all Multis in this configuration with control relay connected only to Aux 1 of master (L1) Multi?

I will add ESS assistant to all Multis, change grid code on all Multis and what about setting of Aux 1? Set Aux 1 for disable feed-in on all Multis together with connection only Aux 1 of master Multi? Or set it only on master Multi?

And is it possible to connect Aux 1 on all Multis to one 3 pole relay, set disable feed-in on all Multis - as backup, if there is a problem for example with one pole contact of relay or Aux 1 input of master Multi?

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