Abstract
Sulphur hexafluoride (SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> ) insulated vacuum interrupter circuit breakers have been used to explore replacing SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> gas with a trifluoroiodomethane and carbon dioxide (CF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> I-CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) gas mixture. The search for an alternative insulation gas is driven by the well known extreme global warming potential of SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> . For this purpose, the circuit breaker gas compartment of a piece of gas insulated switchgear (GIS) was filled with a CF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> I gas mixture and then tested using lightning impulses up to the rated withstand strength. The tested ring main unit was initially designed to be insulated with SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> gas. The unit is a three-phase switchgear containing two switches per phase; a selector interlock and a vacuum bottle circuit breaker per phase. The test programme performed in this investigation demonstrated the breakdown performance and insulation strength of the new gas mixture as well as the vacuum circuit breakers behavior when insulated with a new insulation medium. Data on the dielectric properties of the proposed gas mixture is presented, and the performance of the tested vacuum circuit breaker is discussed. Promising results are obtained which indicate the suitability of this more-environmentally friendly gas for high voltage insulation purposes.
Highlights
IN the power industry today, several designs and examples of medium voltage (MV) switchgear using vacuum bottles / interrupting technology can be found
A Ring Main Unit (RMU) with vacuum interrupters have been insulated with a CF3I-CO2 gas mixture and subjected to a number of tests to investigate the insulation properties and the suitability of the proposed gas mixture as a replacement to the currently-used SF6 gas
To test the insulation strength of the gas surrounding the vacuum circuit breaker interruption chamber, the ring main unit (RMU) was Investigations with 30%:70% CF3I-CO2 gas mixture at 0.4 bar(g) and basic impulse level (BIL) test voltages of 75 kV show that the application in MV switchgear is promising and demonstrates an alternative high voltage insulation medium to SF6
Summary
IN the power industry today, several designs and examples of medium voltage (MV) switchgear using vacuum bottles / interrupting technology can be found. This paper examines the potential of using CF3I-CO2 as a direct replacement to SF6 in switchgear which utilizes vacuum technology From published literature, it has been reported [3] that CF3I gas has limited capability for arc interruption when arc currents are higher than 100A. IEEE Transactions on Dielectrics and Electrical Insulation Vol 23, No 1; February 2016 and only insulates the equipment such as around vacuum circuit breakers is a promising prospect In this investigation, a Ring Main Unit (RMU) with vacuum interrupters have been insulated with a CF3I-CO2 gas mixture and subjected to a number of tests to investigate the insulation properties and the suitability of the proposed gas mixture as a replacement to the currently-used SF6 gas
Sign-in/Register to view highlights & summary 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 callMore From: IEEE Transactions on Dielectrics and Electrical Insulation
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
