ECN Forum Forums Technical Discussion Electrical Theory and Applications Why is this setup used?

This question had me thinking real hard before I figured out the answer. Let's see if someone else can figure it out.

What are 132 kV single phase lines used for? These are found in Europe, sometimes next to ordinary 3-phase HV lines, like 230 kV.

Could it possibly be train supply lines (THIS IS ONLY A GUESS)

[This message has been edited by james S (edited 10-17-2003).]

Is this a trick question?
I would assume they are used for conducting electricity, otherwise why build them?

As far as I know the Train thing is right. It's transformed down to 15 kV for Railways, frequency of 16 2/3 Hz.

From www.electric-railways.co.uk :

James,

that was a quick answer. It is indeed the transmission for the train lines. Andy and Paul are right about the reason - the frequency is different from that of the ordinary power grid.

Paul UK,

I think your source is wrong. Denmark uses 50Hz, 25kV for the trains whereas Sweden and Norway use 16 2/3Hz, 15kV. This has forced trains that run between the countries to be dual voltage / dual frequency.

[This message has been edited by C-H (edited 10-19-2003).]