I don't know about the rest of Europe but here in Ireland we use substations in urban areas.
Power would come in from the grid at transmission voltages of up to 400kV to a large substation near a town/city. It's stepped down to a medium distribution voltage of either 38kV, 20kV or 10 kV and from there goes out to local substations.
Typically every new housing development or each area of a city would have one. They often provide a number of 3-phase +N (380V) circuits which would be distributed either underground or overhead.
Small commercial users (small stores etc) and domestic users typically take 1 phase + N (220V, nominally 230V)
Other users take 3 phases 380V (nominally 400V) +N
In rural areas a 3-wire (3phase) distribution system operates at 10kV or 20kV.
Pole top transformers are used to step the voltage down and to either provide 220V (domestic) or 380V (to larger farms/guest houses/hotels/schools etc)
You won't find pole top transformers in towns or even relatively small villages though. They'll always have a small substation.
Even where 2/3 houses are clustered together a larger pole mounted transformer may be used and a small 220/380V overhead distribution system will hook up the houses.
As for types of transformers used. It would depend on the country in question. I know ESB, the main PoCo here uses a lot of ABB and AEG substations.
They also use ABB Pole mounted transformers: (Oil filled can type)
Here's the 3-phase version:
Here's a typical small pad-mounted substations that are used to service a block of houses or a new housing development. You'll find them scattered around the place. They're just large green street cabinates. Often located at the side of a park, down a lane etc..
All of the above are ABB
AEG and Siemens also supply similar set ups.
This is a bulkier looking Siemens transformer, something similar is seen in pole mounted applications here. Or as part offenced off substations.
The large substations that step-down from transmission voltages are pretty serious plant. Usually a large fenced off area with lots of transformers and switch gear.
for further information visit:
www.siemens.com www.abb.com www.aeg.com www.alstom.fr All of the above make transformers for the EU market.
I'm sure there are others too..
[This message has been edited by djk (edited 08-19-2003).]