Use Case
Controlling modes
Example
Installation
Good practices
Use Case
Let's look at limiting the grid import with control over your battery. For this use case, we will install the Peak Shaving controller. Here we do care what the PV is doing.
Controlling modes
Please note this controller changes its behavior depending on the remaining battery state of charge.
There are 5 modes and those modes are in order of decreasing state of charge of the battery:
1 - Self-consumption mode: this is the normal self-consumption (grid target is 0 import/0 export)
2 - Peak shaving (financial limit) mode(financial limit): we limit the grid import by discharging if the financial limit is exceeded, and the battery will charge if the PV is exporting
3 - Peak Shaving Protection mode: we limit the max grid phase current by discharging IF the limit is exceeded, and we charge the battery IF the max current is below the target current.
4 - Charge-only mode: we only charge if PV is exporting, we do not discharge anymore.
5 - Force charge mode: we force charge to protect the battery at the target power in kW.
The SoC selection is the lower limit of the range.
Just so you know, our model supports hysteresis on state changes to avoid alternating between adjacent states (2% on either side).
Example
|
Battery SoC (example values) |
Control Actions |
|---|---|
|
>80% |
Self consumption - normal self consumption at the site grid meter, target grid power of 0. |
|
50% - 80% |
Peak shaving - if the grid import power exceeds the financial target discharge to reduce the grid import. (i.e. maintain grid power <= financial target) If exporting to the grid, charge the battery. |
|
20% - 50% |
Protection - if the grid import current on any phase exceeds the current limit discharge to reduce the grid import. If the maximum phase current is below the current target then charge. i.e. maintain (protection target <= max grid phase current <= protection limit) |
|
10% - 20% |
Charge only - If exporting to the grid charge the battery. Do not discharge to protect the battery. |
|
< 10% |
Force charge - Charge at the target rate |
Installation
To set up the Peak Shaving Controller, simply:
1) Go to the Controller section in the Equipment tab.
2) Click on plus to add a new controller
3) Select the Peak Shaving Controller in Controller type and enter the required parameters for each mode
Please note that mode(s) can be disabled if the SoC value is the same for adjacent modes.
4) Select the Droplet and Devices it applies to, and click Add controller
Good practices
The settings are a trade-off.
You can use more battery for self-consumption at the risk of not having enough for peak shaving.
You'd have to understand what you want to save on and adjust the values based on that.
For example:
a) You want more self-consumption? Reduce the SOC thresholds
b) You want more peak-shaving capacity (if exceeding the peak is of greater concern than self-consumption), increase the SOC thresholds.
c) If it's possible to increase the grid import limit that will reduce the amount of peak-shaving capacity required.