Probably a beginner question, but I’m not able to figure out how I can do peak shaving on a 3-phase grid with a single multiplus II connected to L1.
I live in Belgium and we have something called capacity tarif, where we get charged for the highest peak of the month. On a 3-phase grid, the usages of all phases are just added to each other, so 1000W on L1, 2000W on L2 and -500W on L3 would result in a peak value of 2500W. I would like to reduce the peak usage by activating peak shaving but it is not doing what I hoped it would do.
If I enable peak shaving and set it to 5A per phase, it perfectly limits the current on L1 to 5A immediately when I enable a load. However, it does nothing when exceeding 5A on L2 or L3. Multiphase regulation is set to “Total of all phases”.
While the above solution would be nice if it worked, an even better solution would be that I can set a peak shaving limit to the total of all phases, but I can’t seem to find a way to do that.
The only solution I can think of right now is to implement my own peak shaving in nodered by looking at the total AC consumption, and when it exceeds my limit, disable DESS and set the grid setpoint to my limit. But this seems complicated for a feature that’s already in ESS.
Is there anything I’m doing wrong or is there really no other way than doing it myself through nodered ?
I have an Energy Meter VM-3P75CT connected as grid meter, measuring the 3 phases, 1 MultiPlus-II 48/5000/70-48 connected to L1, and a cerbo GX. The battery is a set of 2 pylontechs US5000, and there is an AC PV inverter on AC-OUT.
I’ve created my own peak shaving logic in nodered and now it’s working perfectly, while the peak shaving function in ess is disabled.
Is the buit in peak shaving meant to work only on the phases that have a MP attached or should it work across all phases ?
I have the exact same problem (also from Belgium)
I’m using a MPII 48/5000 connected to L1 (with the required 018C ESS Assistant), a Cerbo GX, EM24 ethernet grid meter, BYD 15.4kWh battery and have an AC input connected Victron EVCS.
I have implemented my own (successful) peak shaving logic in NodeRed because the one from Victron does not work for our situation.
I would like to use Dynamic ESS but the problem above keeps me from doing this (or I should add some more NodeRed Logic and/or use the Victron DESS NodeRed implementation which I would also not prefer).
So I support the question above to allow peakshaving to work on the combined power of the phases of a 3 phase system with only one MP on L1 (and NOT the input current for each phase separately as that strategy is of no use in e.g. Belgium). And, that DESS would also adhere to the peak shaving settings when charging the battery from the grid with other loads active.
I have the vrm based DESS enabled in my solution, I just disable it when I need to peak shave. When the peak is over, I enable DESS again.
The only other thing you need to take into account is that DESS will discharge to the minimum SOC and you have no capacity leaft for peak shaving. So I reset the DESS target soc to minimum SOC + 5 when it plans to go below.
But ideally, the peak shaving would just work for 3 phases on a single MP II when you have multiphase regulation enabled.
I think you are confusing different features. This is the definition of peak shaving from the manual:
Using the Peak Shaving option it is possible to always let the system keep PowerAssisting when the loads exceed the AC input current limit and it is required, or only above the Minimum SOC parameter.
As soon as the peak is over, it will recharge the battery using power from the grid, while still prioritising solar.
Note that there is a 5% hysteresis; If the Minimum SOC is set to 50%, it will then start recharging back to that 50% only once (by peak shaving) the battery has dropped to 45%.
Also note that this works for the critical loads on the AC output only, not those connected to an energy meter.
The default setting when using the Optimised modes is ‘Above minimum SOC only.’ Use this option in systems that do not perform peak shaving.
What you are trying to do is use grid exporting on the one phase to offset power from the other 2. If you have a 3 phase grid meter and multiphase regulation is correctly configured, the system will try balance the phases to 0, where possible. This is not peak shaving.
From the manual:
Single-phase ESS in a system with a three-phase connection to the utility grid
Single-phase ESS is a single inverter/charger.
Total of all phases" selected - ESS regulates total power L1 + L2 + L3 to 0.
Thanks. I just assumed since multiphase regulation is enabled, and ESS already regulates the sum of the 3 phases to zero, it would also do this for peak shaving. That means I will keep my nodered implementation.
@mrt Here is the json export of my nodered implementation, which is running on the cerbo. It does a lot of things, but the main thing you have to look at is the peak shaving function block. There is a parameter that defines the maximum peak, now at 4000 watts. And the second thing is in both adjust DESS soc and adjust DESS strategy blocks, which keeps the minimum soc 5% above the actual minimum soc, to have a buffer.
Apart from that, the flow assumes you have DESS enabled, since it will act on a few DESS settings. You should be able to adjust it if you don’t use DESS.
What it does is keep the minsoc 5% above the actual minsoc, and adjust the DESS strategy for the current block if required. As long as the ac consumption stays below the peak shaving value, it will only adjust the DVCC charge current so the maximum you pull from the grid is the peak shaving value.
Once your consumption goes above, it will disable DESS and set a manual grid setpoint with the peak shaving value. Any load above will come from the 5% buffer of the battery.
When the peak is over, it will re-enable DESS and set the grid setpoint to 50W again.
Below you can see the 15 minute peaks of my utility meter, with the peak shaving value set to 4000W for the last week. I have an EV and heatpump but never crossed my 4000W.
