Power voltage transformers 1

[Arul_Noble]

Power voltage transformers (Power VTs) combine the attributes of an inductive voltage transformer with the application of a small power transformer. Has anybody worked with PVTs? Throw some light on this topic.

 

[scottf]

Power Voltage Transformers (PVTs) are also called Station Service Voltage Transformers (SSVTs)

They are generally used to provide station power / back-up station power directly from the transmission line. Normally see them in the range of 69kV to 500kV and 50kVA up to <200kVA. The upper power rating and voltage ratings have been pushed up in recent years.

There has been an increase in usage in North America over the past many years due to changes in reliability regulations requiring multiple/different sources of back-up station power. Most common applications are in switching stations (meaning no power transformer tertiary to provide station power) or when there is no distribution line near-by to provide back-up station power from.

 

[Arul_Noble]

Thanks, Is it possible to have PVTs in SF6 GIS substations of 115kV level?

 

[FPelec]

Yes, we installed PVTs in GIS from 72.5kV to 420 kV. To my knowledge, the product is available from at least two suppliers: Hitachi (formerly ABB) and SIEMENS; GE might also have something available, possibly in a narrower range of rated power.

Si duri puer ingeni videtur,
preconem facias vel architectum.

 

[scottf]

Arul_Noble-

Yes, Trench makes PVTs for GIS, however, the power output will be lower than free-standing oil or SF6 PVTs. I believe GID type will be in the range of 20kVA per phase and some users will parallel multiple PVTs per phase if they need higher output.

 

[Arul_Noble]

scottf & FPelec: Thanks a lot for the info.