question

K.G. Friederich avatar image
K.G. Friederich asked

3-Phase Multiplus-II ESS with Enphase - current sensor placement

I am planning a 3-Phase ESS with 3 MultiPlus-II, a Pylontech battery and would like to attach an AC coupled photovoltsic system with Enphase microinverters because of shading issues.

As long as the grid is available, the diagram below should work and Envoy would sense battery charging like another consuming device. Due to the built in backup capability of the MultiPlus-II it is not possible to place the grid-side current sensors the usual way between battery system and cutoff switch As soon as the grid there is a problem with the grid and MultiPlus-II cuts it off, the current sensor (light blue in the diagram) is cut off as well, so Envoy has no means to control the supported Solar energy.

b5545bb4-8895-4ccb-b4fc-06ab555e84cf.png

My concern is that the two systems MultiPlus and Envoy could counteract and hinder each other doing their job.

Can this sensor be placed that it works with and without grit?
Could Envoy get the current sensor data directly from the three MultiPlus-II?
Is there a direct way to control Envoy or the Microinverters from MulitPlus-II or Cerbo?

(This is my first post in an energy community and im not firm with the termIndology epecially in English)

Multiplus-IIESSAC PV Coupling3 phase
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3 Answers
juergenal avatar image
juergenal answered ·

Hi,

I'm in the same situation as you at the moment. But I would say that the current sensors for the enphase have to be installed after the Victrons and not before, because the Victron says how the frequency and the currents should run and not the grid. And in the event of a power failure, a grid is set up and controlled by the Victron.

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K.G. Friederich avatar image
K.G. Friederich answered ·

If the sensor is insatalled after the victrons, an the grid fails, Multiplus opens the switch to the grid, so the current sensor will sense no current which leads to the question if envoy will shutdown the PV with it‘s anti islanding feature.

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juergenal avatar image
juergenal answered ·

I meant after Victron of course at the AC1-Out and not at the AC1-IN

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