44 kV pad mounted transformer - where to find

[ters]

My Client in Canada has an unusual request to connect a small 400 V, 2000 kVA generator to a 44 kV grid using a pad mounted step up transformer 0.4/44 kV WYE/DELTA with both 400 V and 44 kV cable terminations located inside a metal enclosure bolted onto the transformer.

The transformer enclosure should also somehow accommodate fuses on the HV side (probably hidden somewhere behind HV terminals and accessible from the top).

I can’t seem to locate any manufacturers who would can make CSA (or ANSI) approved pad mounted transformers at 44 kV level (or 46 kV), and especially not with fuse assemblies built-in. Transformer manufacturers I contacted would go with pad mounted design with or without fuse up to 38 kV max (usually up to only 34.5 kV). Over 38 kV only transformers with external top or side mounted bushings would be available. Does someone have an idea how to approach this? Thank you in advance.

 

[dpc]

You can buy substation-type transformers with side bushings and air terminal compartments. Not sure if you can go as high as 44 kV, but I would talk with transformer suppliers and see what your options are.

Pad-mounted units are more standardized, so there may not be as much flexibility there.

 

[ters]

Thank you. It does not look primising, 2 manufacturers said that could not do it. Still trying...

 

[rbulsara]

Why not ask the clients who are requesting this, if they have done this (44kV) before and if so where did they get the transformer?

If they have not, then ask where does the spec comes from? May be the specs are based on lesser voltage equipent. It may be time to educate the client. I would rather check with some leading manufacturers though.

 

[ters]

The substation type TR wouldn't be a problem to find. But pad mounted doesn't seem to exist at that voltage level (44 kV), although I still have not given up.

The Client is also unaware of such application. Since this is a private wind farm, where normally the collection voltage would be lower, say 13.8, 22, 27.6 kV, etc, for which a pad mounted TR is easily available, and then that voltage would be further stepped-up to a public network by another substation type TR 27.6/X kV (where x = 44kV in this case).

My client is, however, researching options as how to reduce the cost eliminating this intermediate TR, which would be fairly large (10 MVA - for 5 units connected to the same line) but for now seems rather unlikely to find anything except conventional substation TR type with bushings, what the Clinet don't seem to like - should be something tamperproof such as pad mounted...