Vacuum circuit breakers and “clean air” insulation replace SF6 as switching and insulating medium
Siemens Energy Management has received an order from Bergenshalvøens Kommunale Kraftselskap (BKK Nett) in Norway to supply the world’s first SF6-free GIS with “clean air” and vacuum interruption systems for a voltage level of up to 145 kilovolts (kV).
The switchgear is part of the Koengen substation in Bergen, which shall supply electricity from renewable energy sources to Norway’s largest cruise ship seaport. Non-conventional systems for measuring current and voltage allow the switchgear to have a much more compact design.
The start of the collaboration was celebrated on November 5, 2018, at Siemens’ headquarters in Bergen. Commissioning is scheduled for end of 2019.
The number of cruise ships in Norwegian waters is rising continuously. While only 100 ships berthed in the Port of Bergen in 1990, Bergen Havn expects this figure to rise to 300 in 2018. As a result, Norwegian seaports have set themselves the goal of reducing harmful emissions during ship lay times.
One measure is to supply more and more ships with shoreside electricity from hydroelectric power. To provide the necessary grid infrastructure to handle higher voltages, the Norwegian energy provider BKK Nett is upgrading its transformer substation in Bergen from a 45 kV to a 132 kV operating level, making it state of the art.
The order includes 3 bays of the 8VN1 gas-insulated, SF6-free 145 kV switchgear. This GIS uses vacuum interrupters for switching functions and treated air, known as “clean air”, as the insulating medium. It is therefore possible to completely eliminate the use of sulfur hexafluoride.
With this project, a gas-insulated switchgear with vacuum interruption systems and “clean air” technology for a voltage of up to 145 kV is being delivered for the first time in the world.
“The large proportion of hydropower in Norway’s power system makes it the world’s most climate-friendly system. Now we are investing in a pilot project which uses an environment friendly alternative to SF6 gas, thus becoming the first project of its kind in the world with this technology. Siemens is a solid supplier, and we expect them to develop this technology further,” said Wenche Teigland, CEO of BKK Nett.
The first “clean air” vacuum circuit-breaker and “clean air” instrument transformer went into operation in a German 110 kV high-voltage grid in June 2018. “This order for an SF6-free high-voltage switchgear in Norway demonstrates that our customers are attaching more and more importance to sustainable grid technology,” says Ralf Christian, CEO of the Siemens Energy Management Division.
“The SF6-free GIS from our so called
“blue portfolio” requires no special precautions to be taken during operation and recycling and offers top technical performance, maximum safety, and reliability. There is also no longer any need to report the quantities of fluorine gas used.”
The ordered 8VN1 GIS features a rated voltage of 145 kV, a rated short-circuit breaking current of 40 kA, and a rated current of 3,150 A.
The order includes three bays of the 8VN1 gasinsulated, SF6-free 145 kV switchgear