Automatic fault isolation

Elenia Oy, a DSO (Distribution System Operator) in Finland serves about 430,000 customers on its electricity network. Elenia has long been investing in automating features of its electricity network. The DSO took a significant step in the automation process when they adopted automatic fault isolation, or FLISR (Fault detection, Location, Isolation and Supply Restoration), to deal with electricity network faults.

When a fault occurs in the electricity network, FLISR detects and locates the fault and isolates it from the rest of the network, restoring power to the areas of the network remaining operational. All this is done automatically. The system is particularly useful for electricity networks in rural areas.

Turo Ihonen, the Maintenance and Safety Manager at Elenia, was involved in configuration and deployment of the system: "For us, FLISR is a tool that allows us to make better use of the investments we have made in our electricity network."

The application benefits Elenia's customers, the electricity consumers. "When dealing with an ordinary storm, FLISR enables us to restore the electricity network more quickly in case of outages. The fault area is isolated automatically, and power can be quickly restored to the residents outside the fault area by using the healthy parts of the grid. This will reduce the duration of power outages."

Software Manager Jukka Kuru from Trimble says that, at best, the system can restore power to most of the consumers affected by an outage within minutes.

The automatic Fault detection, Location, Isolation and Supply Restoration system, FLISR, produces a fault isolation sequence for each detected fault. This includes the switching activities that can be performed remotely in that particular fault profile. Instead of full automation, the control room can also use the system to decide what to do next. Safety is important, which is why the staff always have the option to stop the automation process.

​More time for work management

In the event of a large-scale storm, damage can be so widespread that a healthy electricity network can no longer be found. However, efficient fault isolation automation is still useful. "It frees the control room from network management to managing the repair procedures that are underway in the field. Both crew management and the overall management of the situation are improved," Ihonen explains.

Also Kuru refers to large-scale storms and says that Trimble DMS functions reliably, even though information has been flooding into the system. "We have experience with large-scale faults and have developed the system to a high standard. We can definitely say that the system's operational readiness is good, even in extraordinary circumstances."

Efficient communication

According to a consumer study on power outages conducted by the Finnish Energy organisation, consumers are most affected by the lack of information on the duration of power outages.

Elenia offers its customers an online outage information service implemented with Trimble's Outage Communication application. Using the outage information service, Elenia's customers can receive information about power outages via text messages and email as soon as the fault is detected. The customers are notified immediately after an initial estimate of the duration of the power outage is generated. The service is automated and Outage Communication also ensures that information from different sources is always up to date.

Elenia's customers can also receive information by viewing an online outage map or by phone from an interactive voice response (IVR) based on the outage situation.

"For example, during one severe winter storm, our online outage map had over 300,000 visitors," Ihonen says. "These communication services have made a difference for our consumers. The number of incoming calls in our customer service has decreased because the customers can receive information about power outages directly on their mobile phones." ​