Within an unbundled electricity market, Dutch distribution system operator (DSO) Stedin is under pressure to have visibility on all parts of its network.
The DSO has a customer base of 2.2 million customers serving an area of the central-western Netherlands containing four major cities - The Hague, Utrecht, Rotterdam and the Rijnmond port and Botlek area.
With such a busy urban and commercially vital service territory, Stedin needed to show its stakeholders, the regulator and its executive team that it is drawing enough information from its grid to prevent outages, improve maintenance streams as well as prepare for the growth of electric vehicle connections.
The business drivers were plentiful for digitising grid assets, some of which have been in the field for up to 40 years, explains Anne van der Molen, Grid Strategist at Stedin. “The information we were receiving from the grid was limited by data silos. To improve our asset performance management, we needed to get real-time operational data.”
Stedin looked to its substations as key points on the medium-to-high voltage network that needed more visibility in order to better manage its assets portfolio.
As part of a plan to digitise Stedin’s 185 substations, the DSO entered into a pilot with asset management platform specialist OSIsoft to prove the concept.
The pilot focused on one substation in downtown Utrecht being run on international standard IEC 61850, a communication protocol for substation automation that the DSO has adopted since 2007 and is implementing across its network.
Digitising a Dutch substation
The goals for the substation project were two-fold, explains Van der Molen. The first was better maintenance planning - to remove the need for manual inspections - and the second was visibility of in-service performance data of critical assets.
OSIsoft, the US developer of the asset management data management platform the PI System, developed a custom-built PI Connector for IEC 61850 to allow Stedin to visualise and act on real-time substation data.
Van der Molen explains: “You’re only as good as the information you’re getting from your SCADA historian. And, if you want to change that, you need to change basically the interface from the substations or the equipment in the field to your SCADA.”
Substation visibility through real-time data
With data from the Utrecht substation appearing in real-time at Stedin’s control room, Van der Molen said the utility was able “to get live information from its assets allowing it to remotely add and change the asset when needed.”
“Instead of measuring the entire substation with one feeder, we can now add surveillance and measurements to specific areas to monitor load forecasting.”
One anomaly on the network that Stedin would not have spotted before connecting the substation to its PI platform was the pressure on tap changers that were switching 30 times per day instead of the optimal 16.
As it turned out, trains accelerating at a nearby station were the cause of the energy peaks and with this knowledge the team at Stedin could improve the condition assessments of its grid assets.
Scaling real-time substation data
Based on the pilot and its outcomes, Van der Molen says the case for digitising IEC 61850-compliant substations is “proven”. The biggest surprise, he says, was the speed and ease to get access to substation data. “We allowed for two weeks’ engineering time and instead it took 1.5 hours.”
The next step, however, is to understand how to extend the solution to its 185 substations from a communication technology infrastructure perspective.
Each substation will produce 2GB of data per hour, which when combined with the number of substations is a lot of data. “This just shows the related business case between telecommunications infrastructure and utility digitisation.”
DSO and data science
Another key benefit of connecting substations to Stedin’s existing data management and analytics platform was reducing the burden on the DSO’s data scientists of finding the data.
The utility, one of eight DSOs in the Netherlands, has a team of 10 in its data science department split between data stewards, responsible for data gathering, and the scientists, who are spotting ways to make operational improvements through data analysis.
“If you want to continue to be a DSO in the future, you can benefit a lot from having a data architecture and people skilled with using it. This is becoming an integral part of everybody’s daily job.”