MV Non-SF6 Switchgear

[AVR_1.0pu]

Hi folks,

Anyone have experience with non-SF6 MV switchgear alternatives (like ABB dry air)?
What is it like, any pros or cons?

AVR

 

[dpc]

What voltage? Vacuum circuit breakers are the norm for switchgear in the US up to probably 25 kV.

 

[AVR_1.0pu]

Thanks dpc, I was thinking 11-33kV. We have a lot of sf6 here in UK, for ring mains and main distribution boards.

There is a trend towards non sf6 types due to the environmental issues associated with sf6.

I am fairly familiar with VCB's which are used a fair amount here too, but I was wondering if anyone has had any experience with these novel arc extinguishing mediums.

AVR

 

[dpc]

Vacuum breakers are available up to 35 kV, FWIW. In the US, this is nearly all air-insulated switchgear. Very little gas-insulated gear in use here. Good luck.

 

[ppedUK]

What's wrong with conventional air insulated / solid insulated switchgear in conjuction with VCBs? Most Euro manufacturers offer this design up to about 24kV.

The dry air gear you are referring to is a "compact" alternative to GIS gear, but I'm not sure if it goes higher than 24kV, but I'll stand to be corrected.

The SF6 gear at 11kV that you are probably referring to is mostly RMU (or similar) type gear and provides a compact solution. In these units, the quantity of gas used is quite small as it is normally only used for the breaking medium, rather than for insulation.

For 33(36)kV, GIS seems the economical solution offered by most.

 

[AVR_1.0pu]

Nothing wrong at all with the conventional switchgear.

I was just wondering if anyone had installed it / had any operational experience with it.

 

[veegrid]

@ppedUK,
in North-east USA, I have worked with 33kV dry-air compact switchgear. We do consider GIS for 115kV and above when open-air is not feasible. But lately, Sf6 is becoming very challenging to get approved, and looking towards non-SF6 alternative for that voltage.
For original question, we do have many of dry-air compact switchgear. We use the term "Metal Clad Switchgear" or "Integrated metal clad switchgear". We have them for upto 33kV. Operation people sometime don't like it as it is compact and not much room to do when troubleshooting or part replacement is required. But overall, we see less maintenance for metal clad switchgear. We also started integrated switchgear enclosure with control room under same roof. GReat design and easy to deal with turn key service.

 

[J.Key]

If you are interested in 6,6kv and 11kV ABB AIS SWBD info let me know. Have been working with it for 8years.