I have a 3 phase system with 3 MultiPlus inverters. I use the assistants to manage the programmable relays for ACOut 2.
The ACOut relay is on when it is above a % SOC or when AC1 is available for 60 seconds. This assumes that when there is grid the ESS will maintain a minimum SOC for the battery. If grid fails then the heay loads (on ACOut 2) will be turned off and the battery will support the critical loads during the night till the sun comes up and recharges the battery again. This setting is programmed for each of the 3 phases. See the following settings:
The challenge is now that when one of the grid phases fails, still 2 phases see AC1 coming in. Those phases will continue to allow ACOut 2 to be on and draining the battery faster. Despite that my Color Control does not see grid coming in. As such the battery will not be charged to keep a minimum SOC and the battery will not make it through the night will all the issues that come with it.
Is there a way on how I can solve this issue that I allow ACOut 2 to be on when all 3 phases (grid) are working (and will charge the battery) and not only looking in each MP at their respective phase?
@jorisvn
In a system with the ESS assistant programmed switched as a group is enabled. (Cant be any other way). So one phase rejection means all will invert. That is by design.
On is prioritised over off in assistants.
You can combine the two on conditions into one assistant then both conditions have to be met for it to be on.
Yes, ACOut2 will be on in case AC1 is available for 60S or SOC is higher than 70%.
Indeed it should go off when SOC falls below 65%. However, as this phase (1 out of 3) will see AC1 is available it will keep ACOut2 on. The challenge in this case is that the battery will not be maintained the set minimal SOC as not all 3 phases are working, which apparently is required for charging the batteries. That is the challenge when one of the phases in the grid is down. (that is happening here more often these days) How can I solve that?
@lxonline Indeed the ON is prioritised, that is why it keeps on seeing AC1 on and this keeps ACOut2 on. Despite the battery SOC has dropped below 65%. As not all three phases are working, it means the battery is not charging. Or should the batteries be able to charge from 1 or 2 working out of 3 phases?
@jorisvn
Switched as a group in three phase means one rejects they all switch to inverting. So that is by design for an ESS system.
The assistants logic work as AND / OR. Combine the conditions for on in one assistant (you can select more than one switch condition in the wizard.) It changes the logic to needing both to be true to switch on. Side effect will be though that the load wont switch on even if grid connected until the battery is charged to over the percentage set.
@lxonline
In our situation I have for each phase a separate set of rules. Whereby each phase has a different SOC % threshold and one phase does not even go on when the grid is there but the SOC is below the threshold. (and phase 1 has all the ESS settings)
See them all below. Is this what you mean by grouped?
That gives two conditions that must be true at the same time for the ac2 relay to switch on. Instead of one and one.
The ess assistant being different on L2 and L3 is normal, since the L1 is the master decides what is happening the other follow as a group.
@lxonline If I choose both of them to be true, that means that when the battery is drained teh ACOut2 is not on despite the grid is there. Then I need to have the minimum SOC of the system higher than the individual threshold to have it working when there is no sun power.
I like my current settings, but if one phase of the grid is not working then the system is not charging the batteries and maintaining the minimum SOC with even ACOut2 draining the batteries faster. I would like to see of there is an option to replace AC1 input to Grid as visible on the color control screen.
Maybe look at using node red to switch to node red for the extra control.
Rejection unfortunately is not the same as not being there. The logic on the plc is too simple for that.
I have used an unorthodox use of the generator assistant to drive acout2 to achieve what you are trying. Although it has not been tested in grid rejection conditions.
Yes, Node Red could be a next step to pursue, but that requires a bit more programming I guess. Do I then also need to program all the ESS rules?
Do you think the generator assistant could serve as a replacement for the input in the assistents to say if ACin is ON or not? (then I hope that the generator assistant gets triggered if 1 or more phases of ACin are not working, so that could solve the issue)
No the base programming of all the units remains the same with the exception of the ac2 out relay. What you will need to do is use a relay on the cerbo (or a smart switch to drive load) to drive the t sense or something to operate ac2 out.
The generator assistant can be used to drive an ac ignore.
Do you have a generator? If not you can adapt the generator start stop on the gx to drive the connection to grid.
We have a generator, but that is not communicating to the color control as it is too far apart of each other. So I could use that generator start stop function on the GX to identify if there is grid and use that as trigger to replace the ACin trigger in the assistants?
That sucks. Generators can be started over distance using LoRa and Node red. Or a smart switch and node red depending on your WiFi availability near the generator.
The GX option means you can change parameters when wanted though easily in the interface. Not sure how that works with AC detection either.
