Why is ESS sending battery power to grid to much?

DIY
, , ,
1

Hi there!

We recently finished setting up an on-grid system for our home which consists of:

3x Multiplus II 48 / 5000 / 70-50
4x US5000 Pylontech batteries
1x SolarEdge ~13kW PV inverter
2x Lynx Distributor 1000
1x Ekrano
1x VM-3P75CT ( not connected yet )

The overall wiring goes in the order of

PV Inverter & House loads > AC Out
Grid > AC In
Lynx > You know where it goes to… :stuck_out_tongue:

Ekrano has all devices except the Lynx connected to itself.

All multiplusses have the same ESS assistant and same same settings across each other.

ESS is correctly as for what we know configured in the multiplusses ( PV Frequencies, Is connected to AC Out ? yes, DC voltages are checked)

Ekrano has the latest ( beta & large ) version of venus.

ESS is set mostly to default, Mode 1( Optimized + BatteryLife ), Minumum SoC 20%, self-consumption(which we cannot change ?), Grid setpoint 20W, AC-coupled-PV - feed in excess is enabled)

ESS work completely fine, loads, discharge and manages all of the system.

BUT.

Why does ESS waste a lot of energy to the grid, whilst it is intended for own use ?

6014783677650815781
60147836776508157811212×804 67.5 KB

From what i have heard, i could just turn on AC Ignore and therefore disconnect the grid.

BUT i have also heard from a Victron technician that switching the relays overtime would cause more “stress” on the relays and could therefore potentially fail way more earlier than it was likely intended for, as the current system, doesnt switch any of the relays at all ( unless the grid fails ofcourse )

Is it a problem to us? Not really, but it seems strange, as it is not a phase compensation ( by the looks of it )

who knows something about this mystery ?

2

Hello @Hurde , welcome to the forum. Why didn’t you connect the grid meter to make sure, the system has accurate information about your overall grid energy flow?

3

It is recently connected ( like a few hours ago ),

But as grid metering could be done from the inverters, we simply tested and started the system without the external meter, because the external meter was in use elsewhere at the time.

but you’re suggesting that the external meter/ internal meter, could be a cause for it ?

4

If all your loads are on AC out and you have no AC PV between your inverter and the grid, it should also work with the internal meters of your MPs. Was just wondering why you have a separate grid meter but did not connect it :slight_smile: Did something change when you switch the ESS Grid Metering to the VM-3P75CT?

5

it’s connected a couple days ago..

but i am not sure wether its better or not.

it does seem to return a lot less now, but it also seems at the cost of violence.

its really bizarre to see the grid measurements going everywhere, whilst the pv inverter and ac loads are perfectly stable..

im not sure how to think about it..

6

si le VM-3P75CT est connecté (avant tout consommateur et sur chaque phase) il faut retirer les pinces bleus des multiplus. s’il n’y a pas de pinces bleus alors enlever le pont (current sense) sur chaque multiplus 2. pour le test régler ess sur optimisé sans batterie Life

7

In what mode is your ESS at? Green mode or trade mode? If on trade mode it will ignore the setting of 20W on grid meter and will just follow the predictions for trading with high and low energy prices.

8

@Axelfolly would it really make a difference to remove these components ?

@darryl12123 Dynamic ESS is turned off.

sofar, the system works pretty decently, keeping the grid pretty much near 0

9

si le système se tient proche du zéro pour la valeur grid alors c’est normal. mais il est vrai que la valeur fait des changement rapides, ceci est normal