Re: LF: 33 Hz QRM

[Johan Bodin <jhbodin@tele2.se>]

That problem can be solved by using a return line and booster transformers that minimises current leakage into surrounding earth:

https://library.e.abb.com/public/f1200714de5086c585257d7300287357/1LFI2026%20special%20power%20transformers%20for%20railway%20-%20brochure%20EN.pdf

73 de
Johan SM6LKM

Den 2016-03-17 kl. 15:18, skrev Andy Talbot:

Is that to minimise skin loss in steel track ?

UK Third rail is, of course, DC, and I once spent an idle moment calculating the loss if 50Hz AC were to be used with magnetic iron conductors.  I think I came to the conclusion a 1MW train could probably travel a few hundred metres before it lost its power supply.

andy  G4JNT

On 17 March 2016 at 13:21, Johan Bodin <jhbodin@tele2.se> wrote:

Railway QRG is 16 2/3 Hz in Sweden too.

73 de Johan SM6LKM

John Rabson wrote:

I seem to recall that some railway systems use at about 16 2/3 Hz (one third of 50 Hz) for traction.

...

Can someone say whether my recollections are correct, please?

73 John F5VLF