SAMPLE HEADLINE FOR THE PRESENTATION© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
Alternatives gases for future SF6 free HVDC GIS - focus on PD behaviour and detection
CIGRE e-Session 2020 (SC A3 & B4) | Forum on HVDC Grid Technologies – HVDC Switchgear
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© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714. 2
Introduction - SF6 gas: pros and cons • SF6 is the most used insulating gas in switchgear since 1960
1 kg 23 500 kg
• SF6 is a very good dielectric gas: • High dielectric strength • High arc quenching capability
• SF6 is one of the six greenhouse gases included in the Kyoto protocol list • Highest known Global Warming Potential GWP (23 500
times higher than that of CO2) • Very long lifetime in atmosphere (3 200 years)
SF6
CO2
• To decrease the impact on the environment SF6 should be replaced by alternatives gases with lower GWP but with the same dielectric behaviour
HVDC gas insulated systems – Alternative gases
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© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714. 3
Introduction - SF6 alternatives • Different SF6 alternatives have been studied in the recent years, including natural gases and
new synthetic gases • Among them some emerged as good candidates to replace SF6 in high voltage equipment
High dielectric strength
High boiling point
*From 3M brochures
Fluoroketone (C5-FK) NovecTM5110
Fluoronitrile (C4-FN) NovecTM4710
Atmospheric Lifetime (yr)
Very low environmental impact
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© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714. 4
Alternative gases applied to HVDC GIS • Fluoronitrile mixtures and fluoroketone mixtures are already in
operation in HVAC GIS • Limited information is available on their use under HVDC voltages • To develop reliable SF6 free HVDC GIS their performance should
be verified: • Dielectric behaviour: breakdown voltage, long term characteristic… • Short and long term partial discharge (PD) behaviour
• An effective diagnostic and monitoring of HV GIS/GIL during commissioning and on-site should be based on partial discharge detection.
Some questions emerged:
• How PD’s behave in SF6 alternative gases? • Are the PD detection methods and monitoring systems effective with alternatives gases?
SF6 DC HVDC GIS
HVDC gas insulated systems – Alternative gases
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© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
To OMICRON
To oscilloscope
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0.0E+00 2.0E-10 4.0E-10 6.0E-10 8.0E-10 1.0E-09 1.2E-09 1.4E-09 1.6E-09 1.8E-09
0 200 400 600 800
Vo lta
ge (k
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© PROMOTioN – Progress on Meshed HVDC Offshore Transmission Networks This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 691714.
HVDC gas insulated systems – Alternative gases
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Results and Conclusion • PD behavior of alternative gases in presence of protrusions
is comparable to that of SF6 but some differences have been evidenced on PD amplitude and repetition frequency.
• The detection of particles on insulating material rests a challenge due to the low PD amplitude for both SF6 and alternative gases.
• All the tested measurement systems are able to detect the PDs with a minimum amplitude of 2 to 5 pC
• For long term behaviour, the same conclusion can be drawn
The replacement of SF6 by SF6 alternatives is not an obstacle to use effective PD monitoring systems thereby
It opens the way for the development of reliable future SF6 free HVDC GIS
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PD a
m pl
itu de
(p C)
Voltage (kV)
SF6 500 kPa 10% FN-CO2 650 kPa 4% FN-CO2 800 kPa 6,6% FK-Air 750 kPa
SF6
• Further information: • Session paper D1-123: Measurement and behavior of partial discharge for SF6 substitute gases in HVDC GIS/GIL
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Thank you for your attention. For further questions, don't hesitate to contact me.
Caterina Toigo caterina.toigo@supergrid-institute.com / +33 7 62 20 16 62
North Sea Grid for the European New Deal How to unlock Europe’s Offshore Wind potential – a deployment plan for meshed HVDC grid
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Alternatives gases for future SF6 free HVDC GIS - focus on PD behaviour and detection
Introduction - SF6 gas: pros and cons
Introduction - SF6 alternatives
PD testing and measurements
Results and Conclusion