# Grid settings

> The grid settings of a Voltmasters EMS project: main meter and connection type, access power, desired monthly peak and safety margins, scheduling a change, the grid connection references and the reactive operating point.

Source: https://voltmasters.io/en/docs/voltmasters-platform/project-settings/grid-settings/

Found under **Configuration → Grid & market → Grid settings**.

## Grid connection

### Main meter

Select the energy meter that acts as the **main meter** (head meter) for this installation. This is the meter that measures the total exchange with the electricity grid. Reports, dashboard figures and many screens that display grid data use this meter as their primary source.

### Grid connection type

Configure whether the installation is **single-phase** or **three-phase** to match the actual grid connection at the site. It should match the connection document from the grid operator.

### Access power (consumption) and access power (injection)

The **contractually granted** maximum power of the grid connection, in kW: what you are allowed to draw from the grid and what you are allowed to inject into it. The EMS never plans beyond these values.

> **Warning**
>
> Enter what your contract with the grid operator says, nothing more. If the site draws more than its access capacity for longer than 15 minutes, a peak tariff surcharge from Fluvius may apply.

**Where to find your access capacity**: on [mijnfluvius.be](https://mijnfluvius.be) or in your grid connection contract. The injection side is stated in the same contract, and is often the sum of the capacities of the local generation sources.

> **Note**
>
> On a **three-phase** connection with a main meter that measures per phase, the EMS also keeps each **individual phase** within its share of these limits, so an unevenly loaded phase is protected even when the total is still under the limit. See [per-phase protection](https://voltmasters.io/en/docs/voltmasters-platform/device-management/device-settings/load-management/#unevenly-loaded-phases-per-phase-protection) under load management.

## Monthly peak and safety margins

![Part of the grid settings with six numbered parts. 1: Access power, 160 kW consumption and 250 kW injection. 2: Desired monthly peak, 147 and 250 kW. 3: the Steer on a realized monthly peak switch. 4: the consumption peak of last month (155.7 kW) and this month (187.5 kW). 5: Safety margin, 5 kW per direction. 6: Effective EMS limit, about 142 and 245 kW.](https://voltmasters.io/assets/docs/grid-settings-peak-tour.webp)

1.  **Access power**, per direction.
2.  **Desired monthly peak**.
3.  **Steer on a realized monthly peak**.
4.  The **consumption peak** of last month and this month, for information.
5.  **Safety margin**.
6.  **Effective EMS limit**, with the live value. Here 147 − 5 = 142 kW for consumption.

### Desired monthly peak (consumption) and desired monthly peak (injection)

The peak you do not want to exceed this month, in kW. This is where you tighten the connection beyond what the contract allows: the EMS controls against the **lower** of the access power and the desired monthly peak. It may not be set higher than the access power. When it equals the access power it applies no extra cap; that is also the value it holds as long as no own value has been chosen.

When the desired monthly peak changes on a date you already know, you can [schedule the new value in advance](https://voltmasters.io/en/docs/voltmasters-platform/project-settings/grid-settings/#applying-a-capacity-change-now-or-later), just like a new access power.

How low you can set it depends on how much local energy (solar, battery) is available. The lower the peak, the more the EMS has to lean on local generation and storage to stay under it.

To help you choose, the desired monthly import peak shows **Consumption peak last month** and **Consumption peak this month** underneath it: the highest quarter-hour average of the site's **own consumption** in that month. That is everything the site consumed, including the part covered by solar and battery, and not what was drawn from the grid. The peak can therefore be higher than the import on the grid meter, and shows how much local generation and storage it takes to stay under a given monthly peak. The values are for information only and appear as soon as there are consumption measurements for that month.

### Steer on a realized monthly peak

A switch under the desired monthly import peak, **off by default**. It is meant for the month in which things go wrong anyway. When the site draws a quarter-hour above the desired monthly peak, for example because of an unforeseen high consumption that the battery and the production could no longer absorb, the capacity tariff for that month is already set on that higher peak. Steering below the lower limit then still costs battery cycles and shed loads without saving anything.

With the switch on, the following happens:

-   Once a day, at night, the platform looks up the highest quarter-hour average of grid consumption since the start of the month on the grid meter. When it is above the desired monthly peak, the EMS steers on that **realized monthly peak** for the rest of the month, rounded down to a whole kW. A peak drawn during the day therefore counts from the following night.
-   The page then shows that value as an extra row **Realized monthly peak**, and the effective EMS limit uses it.
-   The access power stays the upper bound and the safety margin is still subtracted.
-   When a new month starts, the limit returns to the desired monthly peak.

The switch only applies to consumption, and only has an effect when a grid meter is set and the desired monthly peak is lower than the access power. It takes effect as soon as you save, also when you pick an effective date for the other grid settings. When you switch it off, a realized peak is dropped straight away and the EMS steers on the desired monthly peak again.

### Import safety margin

**Add a safety margin** is a separate switch, for installations where not all devices follow a setpoint accurately. The margin is subtracted below the desired monthly peak, so a device that overshoots slightly does not push the site over the limit:

**Effective EMS limit = the lower of the access power and the desired monthly peak, minus the safety margin**

When the EMS steers on a realized monthly peak this month, that peak takes the place of the desired monthly peak in the consumption calculation.

The page shows that result per direction as the **effective EMS limit**, with the live value alongside it, so you can read straight off what the EMS is actually controlling against.

As a rule of thumb for the margin: **2 to 5 %** of the peak for installations with stable power flows and fast control, **5 to 10 %** for most installations, and **more than 10 %** where control is slow, measurements lag, or several sources can peak at once.

### Export safety margin

The same margin on the injection side, subtracted below the desired monthly peak for injection. It works exactly like the import margin and is entered separately, because the two directions rarely need the same headroom.

## Applying a capacity change now or later

The access power follows the capacity in your contract with the grid operator. When that capacity changes on a date you already know (a new connection contract, an increase after an expansion, a seasonal arrangement), you schedule the new value in advance and do not have to enter it on the day itself. The same works for the desired monthly peak, the safety margins and the connection type.

To schedule a change:

1.  Enter the new values, for example a new **Access power** in the consumption column. As soon as a value differs from what applies now, a warning appears with the field **Effective date for new grid settings**.
2.  Pick as effective date the first day on which the new values must apply. It lies at least two days after today, in the project timezone.
3.  Save and confirm the change.

Until the change is applied, the current values stay in force. The top of the grid settings then shows a **Scheduled grid settings change** block with the planned values, the effective date and the date on which the platform applies them automatically.

Leave the effective date empty and the new values apply as soon as you save.

The platform applies a scheduled change by itself, but not always on the effective date:

| The new values are | When they are applied |
| --- | --- |
| lower than or equal to the current ones | one calendar day **before** the effective date, so the EMS has time to align before your contract changes |
| higher than the current ones on any field | at **00:00** on the effective date itself, in the project timezone |

When you change an access power or a desired monthly peak, the page asks for a confirmation when you save. Those values determine what the EMS steers on and affect both your capacity tariff and your connection contract.

Good to know:

-   A scheduled change records all grid values together: both access powers, both desired monthly peaks, both safety margins and the connection type. If the desired monthly peak has to change along with a new access power, adjust it in the same schedule.
-   A project has at most one scheduled change. A new schedule replaces the previous one, and saving changed grid values without an effective date drops the scheduled change.
-   **Cancel scheduled grid limit change** withdraws a scheduled change. The current values then stay in force.
-   Once the change is applied, the installers of the project receive an email with the new values.
-   The grid meter and the **Steer on a realized monthly peak** switch are not scheduled: they always take effect as soon as you save.

> **Note**
>
> Both the change and the moment it is applied are recorded in the project [activity log](https://voltmasters.io/en/docs/voltmasters-platform/project-settings/activity/), so you can always trace which limits were in force at a given time.

> **Warning**
>
> Schedule a capacity **increase** on the date the new capacity actually becomes contractual, not on the date it was granted. Applying a higher limit too early lets the EMS draw more power than your contract allows, with a peak tariff surcharge as a result.

## Grid connection references

The section is shown for **Belgian projects only**, because the data mandate it feeds is offered by Fluvius for Belgian connections.

Your **EAN number** is the unique identifier for your grid connection point. You can find it on your grid connection contract or on your electricity bill. Add one reference per meter point and pick whether it covers consumption, production or both.

The references have no effect on EMS operation or optimisation. They identify the connection towards the grid operator: a reference is what a [data mandate](https://voltmasters.io/en/docs/device-integrations/energy-meters/fluvius/data-mandate-and-comparison/) is requested for, which lets the platform retrieve the official metering data and compare it against the measurement taken on site.

![The grid connection references with an EAN code and the choice whether it covers consumption, production or both.](https://voltmasters.io/assets/docs/image-85.webp)

## Reactive operating point

Only **installers** with access to the project see and change this section.

For a connection with decentralised production, the Fluvius grid study can impose a **reactive operating point** at the grid connection point: while the site injects, it has to take up inductive reactive power in proportion to the active power it injects. Inductive reactive power lowers the voltage at the connection point, which makes room for the injection. Copy the values from the grid study, and leave the section empty when the study imposes no operating point.

| Field | What to enter |
| --- | --- |
| **Inductive share of the injected power** | The share the grid study imposes: **5 % (cos φ 0.999)** or **10 % (cos φ 0.995)**. Leave it on *No reactive operating point* when the study imposes none. |
| **Second operating point at high voltage (Uc)** | The supply voltage Uc stated in the study, when the study states a second operating point. It sets between which grid voltages the share moves to **32 % inductive**. Leave it on *No second operating point* when the study states none, and the share stays fixed. |

Uc can only be chosen once an inductive share is set. Clearing the inductive share clears Uc as well.

**Where to find the values in the grid study**

-   **Inductive share:** under *Eisen m.b.t. reactief vermogen*, part *Lokale reactieve werking*. The study states the operating point as a power factor and as a share of P: a power factor of 0.999 is *Q = 5 % van P*, 0.995 is *Q = 10 % van P*. Capacitive operation is not allowed, and the EMS never steers that way.
-   **Uc:** the *Opgegeven voedingsspanning Uc* in the connection details of the study. Only fill it in when *Lokale reactieve werking* states a second operating point above a certain grid voltage, with *Q = 32 % van P*. You do not enter that voltage yourself: the EMS derives it from Uc, and it is the voltage at which the share reaches 32 %.
-   **Not in this section:** the part *Remote Q-regeling*, with a Qmax and a Qmin, describes the band Fluvius can impose over telecontrol. That band comes in over the telecontrol link and is not entered here.

![Voltmasters EMS: the reactive operating point settings](https://voltmasters.io/assets/docs/reactive-operating-point.webp)

*A reactive operating point of 10 % inductive, with a second operating point for a supply voltage of 10.5 kV.*

### How the EMS applies the operating point

-   **Only while the site injects.** The EMS holds the reactive power measured at the grid connection point inductive, at the chosen share of the injected active power. While the site imports, nothing is imposed. The regulation is only released after **60 seconds** of import, so a short dip into import does not switch it off.
-   **A narrow band, not one exact value.** The band starts at the required share and leaves some room above it: 2 % of the injected power, with a minimum of 5 kVAr. That way the EMS does not chase meter noise. Being slightly more inductive than required is allowed, because it only lowers the voltage further.
-   **Battery first, PV for the rest.** The EMS asks the batteries for the reactive power first and lets the PV inverters deliver what remains. Only devices the EMS can control take part, each within its own apparent power limit.
-   **A telecontrol order takes precedence.** When Fluvius sends a reactive power order over telecontrol (Netflex, or TCKv4 in remote Q mode), that order replaces the local operating point. With Netflex or TCKv4 in local Q mode, or without telecontrol, the operating point applies.

**Example**

The grid study imposes 10 % and the site injects 400 kW. The EMS then keeps the reactive power at the connection point between **40 and 48 kVAr inductive**: 10 % of 400 kW, with a band of 2 % of 400 kW (8 kVAr) above it.

### The second operating point at high voltage

With Uc set, the share follows the grid voltage. The EMS averages the line voltage at the grid connection point over **60 seconds** and uses that average, not the instantaneous value.

-   When the voltage **rises** past a reference voltage, the share climbs gradually from the base share to 32 %, which it reaches at a high voltage.
-   When the voltage **falls** again, the share drops back gradually, between the reference voltage and a lower voltage.
-   In between, the share stays where it is. This hysteresis keeps the operating point from swinging back and forth with the voltage. Without a voltage measurement the share also stays where it is.

The low, reference and high voltage follow from the Uc you choose. They come from the Fluvius document *Reactief werkingspunt decentrale productie* (version 2.0, sections 1.1 and 1.2), which can be revised, so this page describes the behaviour and not the values themselves.

> **Warning**
>
> These voltages are medium-voltage values, and the EMS compares them with the line voltage the meter at the grid connection point reports. The share can only move when that meter reports the medium-voltage line voltage.

> **Note**
>
> On a PV plant behind an SMA Data Manager, the reactive power setpoints only have an effect once reactive power is enabled on the Data Manager itself. See [Reactive power control (Data Manager)](https://voltmasters.io/en/docs/device-integrations/pv-inverters/sma/reactive-power-control/).