216 until today




IEC 61850

Enexis is responsible for a large portion of the electricity and gas network in the Netherlands. Enexis’ Supply region includes the provinces of Groningen, Drenthe, Overijssel, as well as parts of Flevoland, Noord-Brabant and Limburg. Enexis uses approx. 142,000 km cable network and 40,000 km gas pipelines in these regions in order to supply its 2.5 million electricity and 1.8 million gas customers.


Enexis operates approx. 1,200 medium-voltage installations (MV-T) in its network. The sub-stations have simple busbars with 5 to 20 outputs and are located in the network between the HV/MV transformer stations and MV/LV stations.

Some of these stations have been monitored with the aid of fix-wired digital and analogue inputs for many years. Since 2011, Enexis has also been providing substations with the capability of using medium voltage circuits. Here, the protective equipment is used for interaction with the primary process and the data are transferred to the remote terminal unit via an unmanaged single star IEC 61850 network. The remote terminal unit is responsible for mapping the data from IEC 61850 to IEC 60870-5-104. Due to these different connection strategies, the remote terminal unit must function as both an IEC 61850 client to the protective equipment, as well as assuming basic I/O.

FW-5-GATE as DO Box

The basic DO Box MV-T version is designed for the implementation of telemonitoring and -control from new/modern MV-MV stations. Enex-is will also use the DO box ordered by SAE IT-systems to break up the existing MV-MV stations which have reached the end of their service life. These older monitoring systems are based on conventional, fixed-wired I/O (voltage, current, feed-in capacity, switch position, initiation signal, etc.). As these upgrades are very work-intensive and also result in an increasingly higher depreciation cost due to the premature replacement of existing technology, Enexis plans to add the existing I/O to the next generation of automation systems; the FW-5-GATE with its separate extension boards is a perfect fit here.

“ENEXIS plans to provide comprehensive automation (monitor and control) of its MV network and touch up its old stations. ENEXIS is initiating a European write-down for selecting a remote control solution for the MV-MV stations. The core criteria for this remote control solution is a high level of IT security and communicability. All of the bidding parties were assessed on an equal footing in terms of conformity with the technical specifications, progress made in their IT security measures, user-friendliness, and the ruggedness and performance of the demo systems they provided.SAE IT-systems had the best score in this evaluation process and were awarded the contract.”
Ivan Theunissen, Enexis B.V.