Abstract
After being in the focus of sciences' and industry's research and development activities for many years, the investigation of possible SF6 gas-alternatives has been even more intensified after the revision of the European F-Gas regulation 517/2014. As natural gases yield a significantly lower dielectric strength in comparison to SF6, new challenges arise for the design of high voltage switchgear. Vacuum interrupters are environmentally friendly, reliable and able to withstand steep rising transient recovery voltages. In the last years, first installations of switchgear based on vacuum switching technology in sub-transmission level are in operation. One option for the realization of a SF6 free high voltage switchgear for transmission level is the combination of a gas circuit breaker filled with an atmospheric gas with a vacuum interrupter in a hybrid switchgear. In this contribution the voltage distribution and switching behavior of a hybrid circuit breaker is experimentally investigated.
Highlights
Nowadays sulphur hexafluoride (SF6) is the state-ofthe-art insulating and arc-quenching medium used in gas-insulated switchgear, enabling safe current interruption and high dielectric strength
Using the synthetic test circuit the current amplitude, the current steepness at CZ and the voltage steepness after CZ are set independently to determine the impact on the postarc current
Current amplitude The current amplitude is varied in the range from 2 kA to 16 kA peak current
Summary
Nowadays sulphur hexafluoride (SF6) is the state-ofthe-art insulating and arc-quenching medium used in gas-insulated switchgear, enabling safe current interruption and high dielectric strength. In the field of medium-voltage technology, vacuum circuit breakers (VCB) have almost completely replaced other breaking principles. These circuit breakers are reliable, environmentally friendly and low-maintenance. One possible approach for an environmentally friendly switchgear for the high voltage level is a combination of VCB and gas circuit breaker (GCB) as a series connection. The interest in a hybrid circuit breaker concept has existed for almost 30 years [1], but never became a commercially available switchgear due to the success of the SF6 circuit breaker In this contribution interaction and switching behavior of a CO2-filled GCB and a VCB in a series connection around and after CZ is analyzed.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
