As society is electrified, we become ever more dependent on a robust power supply. To ensure a stable and reliable power grid in the future, technologies that reduce the consequences of faults are needed. Examples of such technologies are systems for automatic fault localisation, isolation, and system restoration (FLISR) or self-healing grids. (Learn what a self-healing grid is in the video above).

To ensure the technologies work, we test them in real environments together with our partners. We are currently running five pilot projects stretching from testing of the reliability of the fault indicators and algorithms for self-healing grids, to reducing the time spent locating and restoring power after an outage.


Fault handling and self-healing

Faster fault location

Automated recoupling in smart secondary substation

If a grid is to be self-healing, automatic location of faults is a prerequisite.

There are already several available technologies which may be used, but they need to be tested. There are also uncertainties regarding centralized vs. decentralized solutions. This project will give recommendations on what equipment to invest in, in the future and pro/cons for decentralized vs. the centralized solutions.

In this project, 20 fault passage indicators (FPI) with earth fault directional detection from different vendors have been installed and are currently being tested together with CINELDI-partner Elvia. The tests have two purposes; To obtain experience with the operation of the devices and verify that the data can be used to find the fault location. Self-healing algorithms have been installed at Frogn (decentralized solution) and Oslo (centralized solution).

Experience is gained every time there is a fault in the network. The aim of the pilot is at least 30 faults.

This pilot is a continuation of the IPN-project FASAD.

Contact person at Elvia:

There are two main motivations for grid companies to find quicker ways of localising faults in the grid.

Every minute a grid company is not delivering energy to its customers, it is effectively losing money. This can be referred to as the cost of energy not supplied. Or CENS for short. Also, every minute spent localising a fault has a cost. Thus, faster fault localisation has a double reward.

CINELDI-partner Elvia has installed approx. 40 fault indicators in the 22kV network. The aim is to see if this reduces the time it takes to find the location of faults and the corresponding reduction in CENS.

Where old fault indicators had to be read manually, new indicators send digital signals allowing fault location to be performed centrally prior to dispatch of maintenance crew. In addition, increased safety and less strain on the components are expected as fewer test recouplings (to test if the fault is temporary or permanent) can be performed.

This pilot is a continuation of the IPN-project FASAD.

Contact person at Elvia:


When customers lose power due to a fault, it is in the best interest of both the customer and the grid company to restore the power as quickly as possible. But localising and fixing a fault is often time-consuming and costly.

Automatic, close to instant fault location and recoupling can reduce the time it takes to restore power after a fault. Lyse Elnett is testing an algorithm for automatic recoupling in an area with long distance overhead lines with frequent faults. The selected secondary substation is equipped with remote control and monitoring and came be fed from two sides.

Contact person Lyse Elnett:


An algorithm for self-healing

Fault indicators

New Relay Concept

A prerequisite for a self-healing grid is automation. CINELDI partner Skagerak Nett is testing an algorithm for automatic recoupling in the Sande area. The area mostly has overhead lines with several faults every year. In additions there are many options for recoupling of the network making it an ideal place to verify the algorithm. As of now, short circuit implemented in the algorithm, while earth faults and phase failure needs more development of the algorithm. 

Contact person at Skagerak Nett:

Skagerak Nett is testing fault indicators throughout its entire grid.

Contact person at Skagerak Nett:  

A new idea for fault localization from Elvia is being tested with simulations and in experiments in the National Smart Grid laboratory.

The goal is to test the reliability of the fault indicators and algorithms for self-healing to reduce the time spent locating and restoring power after an outage.

The main idea is operating the medium voltage network in a ring configuration and, when a fault occurs, combine the fault current measurements from both feeders to locate the fault.

Contact person SINTEF Energy Research: