Pilot projects to improve system security in Eastern Finland

Fingrid has decided to make an investment to reinforce the main grid in Eastern Finland. New connection substations will be built in Happola and Hovinpaikka. An independent circuit-breaker will be added in Äljänä in conjunction with the projects. These projects will improve system security in Eastern Finland. The pilot projects have been developed together with customers and contractors. 

The main grid contains long 110-kilovolt transmission lines with a lot of transmission line connections. Any faults or maintenance on these transmission lines cause outages in customer connections and exacerbate the inconvenience caused by the outage. Fingrid has worked with its stakeholders to seek cost-effective solutions for reducing the area of impact of disturbances.  

The projects in Hovinpaikka, Happola and Äljänä, located near Joensuu in Eastern Finland, were selected as pilot locations because they are located along Fingrid’s 110-kilovolt transmission lines, which are among the longest lines in the main grid. Adding a connection substation and an independent circuit-breaker to the transmission line substantially reduces the area of impact of any disturbances in the main grid and facilitates the arrangement of maintenance outages.  

The construction of a connection substation enables larger transformer connections compared to powerline connections. However, connection substations do not increase the grid’s transmission capacity, nor can they be expanded to handle more than two connections. 

The projects have a total investment cost of approximately EUR 5 million, and all three projects will be completed in 2022.  

Further information: 

Timo Kiiveri, Fingrid Oyj 
SVP, Asset Management, tel: +358 40 543 3039