DSO-RTU Compliance · Fluvius
Netflex 5: remote grid control for large solar and battery installations
Netflex 5 is the latest version of the Fluvius remote control cabinet for decentralised energy resources. Once your installation exceeds the thresholds, Fluvius installs a Netflex 5 cabinet and you must demonstrate that your EMS correctly handles the signals. The Voltmasters EMS is certified for Netflex and guides validation from start to finish.
What is Netflex 5?
Netflex 5 is the fifth generation of the Fluvius remote control cabinet (RTU cabinet). Fluvius installs this cabinet on your site to remotely regulate your installation — solar panels, batteries or other flexible sources — when the electricity grid is under pressure.
Via the Netflex 5 cabinet, Fluvius sends a setpoint to your EMS: how much power your installation may maximally inject or consume. Your controller then translates this signal into concrete commands for the inverters and batteries on site. This way Fluvius prevents local congestion without having to expand the grid at great expense.
Remote grid control is the umbrella term for this system of remotely measuring and regulating decentralised energy resources (DER) via a standardised communication protocol. Netflex 5 is the Fluvius implementation of remote grid control for the low-voltage and medium-voltage grid in Flanders.
Netflex 5 at a glance
- Version 5 of the Fluvius RTU cabinet, the most recent generation
- Communication protocol: IEC 60870-5-104 over secured ethernet
- What Fluvius controls: active power (P), reactive power (Q) and hardware emergency stop
- Mandatory for new or modified grid connections above the thresholds
- Flemish market: rolled out by Fluvius as the distribution system operator for Flanders
Who is subject to the Netflex 5 obligation?
Every new or modified grid connection in Flanders is assessed against the Netflex thresholds. If your installation exceeds one of the limits below, Fluvius installs a Netflex 5 cabinet and your EMS must demonstrably be compliant prior to commissioning.
≥ 250 kVA
Battery storage (BESS)
Battery systems from 250 kW inverter capacity fall mandatorily under Netflex remote grid control. PV capacity and battery capacity are added together for the threshold calculation.
≥ 400 kVA
Congestion zones
In zones where the grid is already under pressure, Fluvius lowers the threshold to 400 kVA. Your grid operator will indicate whether your location falls within a congestion zone.
≥ 1 MVA
All decentralised sources
Solar parks, wind turbines and other DERs of 1 MW or more are always required to connect via Netflex, regardless of installation type or zone.
Note: extensions to existing installations are also assessed. If you add extra PV or a battery to an existing park, Fluvius recalculates whether the combined capacity exceeds the threshold. Not sure? Get in touch for a quick scan of your project.
How does the Netflex 5 connection work?
The Fluvius Netflex 5 cabinet communicates via IEC 60870-5-104 with your own controller (the Customer RTU). Your EMS receives the setpoints and controls the assets. The controller reports the current situation back to Fluvius. This way the grid operator always has visibility into what is happening on your site.
P-setpoint
Active power
Fluvius imposes a maximum value for injected or consumed active power. The EMS adjusts all assets immediately.
Q-setpoint
Reactive power
Fluvius requests a cos φ or Q value to support voltage quality in the distribution grid.
Emergency stop
Hardware disconnection
Via a dry contact on the Netflex cabinet, Fluvius can immediately interrupt all injection. The Voltmasters IO extension monitors this.
Status feedback
Live status reporting
The EMS reports current power values, alarms and asset-category availability back to Fluvius via IEC 60870-5-104.
P-setpoint
Limit active power
Fluvius sends a maximum value for injected or consumed active power. Your EMS adjusts inverters and batteries immediately.
Q-setpoint
Regulate reactive power
Fluvius can ask your installation to maintain a specific cos φ or Q value to support voltage quality in the grid.
Emergency stop
Hardware disconnection
Via a dry contact on the Netflex cabinet, Fluvius can immediately halt all injection from your site. The Voltmasters IO extension monitors this.
Status feedback
Live status reporting
Your EMS reports the current power values, alarms and availability per category back to Fluvius via IEC 60870-5-104.
How the Voltmasters EMS handles Netflex 5
The Voltmasters EMS acts as the Customer RTU that connects the Fluvius Netflex 5 cabinet to your PV inverters and batteries. We handle the full integration: from the initial cabling to the validation session with Fluvius.
- Built-in IEC 60870-5-104 server in the controller: the Netflex 5 cabinet connects directly without an extra gateway
- Voltmasters IO extension for dry contacts: P-setpoint, Q-setpoint, emergency stop and status feedback per asset category
- Real-time translation of the Fluvius setpoint to individual inverters and batteries, taking site limits into account
- Guided validation session with Fluvius: we test active and reactive power, Q modes, emergency stop and all status feedback live
- No conflicts with energy trading: when Fluvius sends a setpoint, the EMS automatically adjusts the energy trading strategy so both remain compliant
Process
From application to Netflex 5 certification
Application
Netflex application
Fluvius determines after your connection application whether Netflex 5 is mandatory. We check together whether your installed capacity exceeds the thresholds.
Hardware
Hardware & cabling
Voltmasters supplies the IO extension and handles the ethernet cabling between the Netflex 5 cabinet and the controller. The emergency stop loop is connected and tested.
Configuration
Configuration & simulation
We configure the IEC 60870-5-104 connection, load the setpoint logic and simulate all Fluvius signals internally before scheduling the validation session.
Certification
Validation & commissioning
Fluvius tests live: P-setpoint, Q-setpoint, emergency stop and status feedback per category. In most cases completed in a single session.
Make your installation Netflex 5 compliant?
We guide the Netflex 5 connection and Fluvius certification from start to finish. Tell us the installed capacity and location, and we will assess together whether and how Netflex 5 applies.
FAQ
Frequently asked questions about Netflex 5
What is Netflex 5?
Netflex 5 is the fifth version of the Fluvius RTU cabinet. Fluvius installs this cabinet at installations that exceed the thresholds so the grid operator can remotely limit injection. Via IEC 60870-5-104, Fluvius sends P and Q setpoints to your EMS, which translates these signals to the inverters and batteries.
From how many kVA is Netflex 5 mandatory?
The Netflex 5 obligation applies to battery storage (BESS) from 250 kVA, to all decentralised sources (PV, wind, etc.) from 1 MVA, and to installations in congestion zones already from 400 kVA. When extending an existing installation, Fluvius recalculates whether the combined capacity exceeds the threshold.
What is remote grid control at Fluvius?
Remote grid control is the system by which Fluvius can remotely measure and regulate your installation to prevent grid congestion. The Fluvius Netflex 5 cabinet communicates with your Customer RTU (the Voltmasters EMS) via the IEC 60870-5-104 protocol. Fluvius sends power setpoints; your EMS executes them locally and reports the status back.
How long does Netflex 5 certification take?
The validation session with Fluvius is completed in most cases within a single day, provided the cabling and configuration are correct in advance. With the Voltmasters EMS we test all signals internally before the Fluvius session, keeping the number of iterations to a minimum.
Does Netflex 5 also work alongside energy trading?
Yes. When Fluvius sends a P-setpoint, the Voltmasters EMS automatically adjusts the energy trading strategy. The priority of the grid operator signal is always respected, but battery trading resumes as soon as the grid operator lifts the active restriction.
Does Netflex also apply to Sibelga and ORES?
Sibelga (Brussels) and ORES (Wallonia) have comparable remote grid control requirements, but with their own thresholds and validation procedures. The Voltmasters EMS also supports these grid operators. Contact us for the specific requirements in your region.
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