Circuit breaker in substation in Norway

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 three bays of the 8VN1 gas-insulated, SF 6 -free 145 kV switchgear.

A circuit breaker in substation is a key component in electrical power systems, designed to interrupt the flow of electricity when a fault occurs, such as a short circuit or overload. Depending on system design, these devices can operate manually or automatically and come in various types, including air, vacuum, oil, and SF₆ gas.

Example 1 - 420 kV substation in Sweden Svonska Krattnt (SvK), the transmission System operator (TSO) in Sweden. is responsible for the 420 kV and 245 kV Systems in Sweden. The Swedish 420 kV system started In the 1950s, and was real ploneering work since it was the frst system in the world at that voltage level.

Example 2 - 132 kV substation in Norway The Grytten substation is part of the Norwegian TSO Statnett's rgional grid. The substation was originally built around 1970. The substation was designed in a traditional manner with a double busbar system (Figure 6a and 6b), and a transfer bus (Figure 6c).

Oil (OCB) use insulating oil to suppress arcs. They are more common in legacy systems and require ongoing maintenance due to oil degradation. SF₆: These breakers, employed in high-voltage substations, use sulphur hexafluoride gas for superior arc quenching and insulation.

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.