High voltage circuit breakers
High voltage circuit breakers are based on advanced application of
gas and material physics, involving extreme condition for the construction
elements. Reliable function and long life are important, and can only be
achived by testing at realistic or provocative conditions.
Simea Optic AB have developt a fiber optic system FMS 300
for measuring pressure in high voltage circuit-brakers. The fiber optic
sensor fulfill the following requirements:
- withstand high voltage
- immune to Electro Magnetic Interference
- withstand decomposition substance
- mechanical robustness
Dead Tank Breaker
Electrical power transmission networks are protected and controlled
by high-voltage breakers.
Current interruption in a high-voltage circuit-breaker is obtained by
separating two contacts in a medium, such as sulfur hexafluoride(SF6),
having excellent dielectrical and arc quenching properties.
After contact separation, current is carried through an arc and is
interrupted when this arc is cooled by a gas blast of sufficient intensity.
Gas blast applied on the arc must be able to cool it rapidly,
in a few hundred microseconds, so that it is able to withstand the transient
recovery voltage that is applied across the contacts after current interruption.
Sulfur hexafluoride is generally used in present high-voltage circuit-breakers.