NOJA Power OSM Reclosers Commissioned in Sweden

Medium Voltage Switchgear Engineers NOJA Power celebrate the commissioning of their OSM Recloser product in Karlskrona Sweden. The Karlskrona installation brings the OSM Recloser installation base above 64,000 units globally, with the latest functionality upgrades of the unit providing high level performance in European style Resonant Earthed networks.

With the installation commissioned and in service, it is entrusted with the power reliability of the Karlskrona archipelago.

From an electrotechnical standpoint, distribution network protection reliability on overhead lines is challenging in the Swedish environment. Dense vegetation and frequent storms and blizzards provide significant obstacles to the reliability of supply.

NOJA Power’s ongoing development in their OSM Recloser’s fault detection technology has enabled the firms’ equipment to operate reliably in Swedish conditions. Key features such as advanced high resolution SEF protection coupled with Smart grid automation technology provides a platform for continuous reliability improvement in the Swedish network.

During 2019, other NOJA Power Smart Grid projects deployed in Sweden showed exceptional network performance against challenging storm conditions, executed in collaboration with Swedish tech company Techinova.

“Resonant earthed networks create capacitively coupled SEF fault current on adjacent feeders that make nuisance tripping difficult to overcome,” reports NOJA Power Group Managing Director Neil O’Sullivan. “With the combination of our low level SEF fault detection capability combined with directional protection to determine whether the fault current is flowing from the source or capacitively coupled back to the source eliminates this nuisance tripping in resonant earthed networks and increases reliability significantly as a result.”

Distribution network reliability remains the cornerstone of network performance for utilities. By maximizing customer uptime, utilities can achieve reliability targets implemented by regulators whilst simultaneously maximizing revenue at the customer meter.

With the implementation of NOJA Power’s OSM Recloser system, most utilities see an improvement of feeder reliability on overhead networks in the area of 80% outage mitigation.