Automatic fault isolation and distribution restoration safeguards the electricity supply in KSS Verkko’s grid | Hitachi Energy

KSS Verkko has more than 50,000 customers in the Kouvola and Iitti areas in Finland. The power distribution company has 12 substations, 63 km of 110-kilovolt lines, 1,500 km of medium-voltage lines, and 3,000 km of low-voltage lines.

Challenge: Outage duration and response time

The Kouvola and Iitti areas have experienced several storms with relatively small impact to grid reliability indices.

Even the most diligent grid operator cannot completely avoid faults in the overhead grid, and overhead lines remain in the grid even after the underground cabling work has been completed. KSS Verkko currently has 30% cabling level in its medium-voltage grid, with a target of 65% by 2036.

"Although we cannot completely avoid faults, we can speed up our response time of operation. We have been investing in remote access to the grid for a long time, and we are able, for example, to control disconnectors largely remotely," says Kai Kuvaja, Director of Technical Services at KSS Verkko.

According to Kuvaja, there has been room for improvement in how quickly it is possible to locate and isolate faults and restore distribution to a healthy part of the grid in human centric operation.

Solution: A fast FLIR system that isolates issues in less than five minutes

With a view to shorten the duration of power outages further, in May 2023 KSS Verkko implemented the fault location, isolation and distribution restoration (FLIR) functionality into the existing Hitachi Energy MicroSCADA system. Because the company already had MicroSCADA's SYS600 grid control system and DMS600 advanced distribution management system, it was easy to enable and quickly deploy the FLIR functionality.

"The biggest benefit of FLIR comes when the on-call operator is asleep or otherwise away from the control system. By the time the on-call engineer has his control system access, FLIR has already done the fault location and delineation in less than a few minutes, and the on-call engineer can directly start a precise search for the fault location in the area delineated by FLIR with the field patrol," says Eemil Hyppänen, Operations Engineer at KSS Verkko.

"KSS Verkko has a standby service with six on-call engineers, but the FLIR solution is useful even when the grid is monitored around the clock from the control room,” said Kai Kinnunen, Sales Manager at Hitachi Energy. He added, "If a large overhead grid has several faults during a storm, FLIR can deal with all of them at once, running up to 50 faults in parallel."

In spring 2023, KSS Verkko identified the feeders where FLIR would be deployed, and almost the entire overhead grid is covered by FLIR. The company will enable FLIR along the cable grid as soon as the level of automation is sufficient for the efficient functioning of FLIR in the cable grid.

Impact: Improved automation and flexibility

"For us, FLIR was a lottery win. It fits very well into our strategy, and we strongly believe it will reduce our outage times in the long run. After all, we want to be a pioneer in introducing automation, and our goal is to add remote monitoring and control to the cable grid as well," says Kuvaja.

As automation increases, KSS Verkko can introduce new ways to use FLIR functionality.

Currently, KSS Verkko's FLIR locates faults by making test connections using a “rolling zone by zone” method, but intelligent fault location based on grid fault detectors, fault currents, and other network data is also utilized by FLIR when available. Intelligent fault location can be flexibly adapted as the number of fault detectors in the grid increases.

Before deploying FLIR, Hitachi Energy configured the functionality according to KSS Verkko's targets and tested it in its test environment that matched KSS Verkko's grid. The utility then gathered user experience in a limited area before integrating FLIR across a wider area.

Even though there was no major storm damage during FLIR’s initial activation period, there were a few individual faults in the grid that FLIR was able to address and resolve. FLIR has now been in active use for six months and has successfully resolved more than ten faults in the grid.

"We have wanted to see how it works, and it has worked well," said Hyppänen.

"We're already in the habit of saying that the ‘flirri’ will do the job," added Kuvaja.

Read more about Hitachi Energy’s MicroSCADA X solutions.