|
Posted to uk.d-i-y
|
|
|
Continental europe having problems with 50Hz
On 09/03/2018 11:32, wrote:
On Friday, 9 March 2018 11:26:05 UTC, Max Demian wrote:
On 09/03/2018 10:15, Andrew Gabriel wrote:
In article ,
Max Demian writes:
On 08/03/2018 23:14, Marland wrote:
Germany and Austria also have a separate grid to distribute power for their
railways,due to the electrification commencing in the 1900€„¢s and the
characteristics of motors of the era a low frequency of 16 and two thirds
was adopted. This low frequency is also used in Switzerland and Scandinavia
but they tend to generate from nearby hydro or convert from the 50hz grid
where required.
They must have 'normous transformers.
3 times the size, and they have to be carried by the train.
However, they couldn't make large powerful motors which ran on 50Hz
at the time, because the winding inductance would be too high to
get the necessary power in without the windings having to operate
at voltages which winding insulation couldn't withstand.
They could have used DC generation, or rectified the AC (if there were
suitable rectifiers in those days).
16Hz is better able to overcome stiction due to its (physically) pulsing nature.
I thought electric trains connect(ed) their motors in parallel mode to
start off, which is why they always (used to) start with a jerk.
--
Max Demian
|