Located in the rolling hillsides of western Sweden, Stensta substation delivers electric power to the town of Kristnehamn. Close by is a wind park that produces 30 megawatts of power, which feeds into the substation and provides the town with a third of its electricity.
Sustainability is the focus
The substation’s owners, Kristinehamns Elnät, recently invested in ABB’s latest technology for high voltage circuit breakers, DCB LTA, a disconnecting circuit breaker with carbon dioxide as the insulating medium instead of the conventional sulfur hexafluoride (SF6) gas.
“The investment is part of our vision to be a sustainable energy company with a strong focus on the environment,” says Linus Andersson, operations manager for Kristinehamns Elnät.
Owned by the municipality, the company follows an ambitious municipal program of environmental targets, a climate plan and environmental policy. It also has its own strict requirements to ensure the products and services it buys meet environmental standards.
Kristinehamns Elnät modernized Stensta substation with four new breakers in 2016. Linus Andersson had no doubts about which breakers to choose.
“The DCB LTA is a perfect match for our demands of sustainability, longevity and efficiency. It saves space by reducing three components into one and requires little in the way of maintenance. Above all, it offers a huge advantage by not using SF6 gas.”
Quality and availability
SF6 is a well-known greenhouse gas. Even if leakages from electrical equipment are rare, care is needed when handling the gas throughout its life cycle. By replacing SF6 with CO2, the environmental impact of the insulating medium is reduced to almost zero and the cost of administering the gas is significantly lowered.
Stensta is a 45/20/10 kV substation that distributes wind power via the transformer and DCB LTA disconnecting circuit breakers to the town and surrounding communities.
“We have a responsibility towards both the wind park owners and our customers to deliver quality power with maximum availability,” says Linus Andersson. “It is a lot to live up to, which is why we selected ABB’s new breakers for their reliability and other benefits.”
Stefan Bergström, sales manager for ABB high voltage circuit breakers, explains that the DCB LTA breakers are based on the same technology as ABB’s conventional SF6 breakers.
“This means the technology is familiar to our customers. Interest is high and many customers make repeat orders after their first installation. The CO2 breakers have the same look and feel as the SF6 breakers; they are reliable and are positive for the environment.”
DCB LTA breakers have fewer parts and a lower environmental impact over their life cycle. The combination of a disconnector and breaker in a single product increases substation availability by lowering the number of components that can break down or require maintenance.