BS EN 50533:2011 pdf download – Railway applications — Three-phase train line voltage characteristics
5 Shore supply
In normal operation the 3 AC train line is supplied by the on board auxiliary converter system delivering a voltage quality as mentioned in Clause 5.
For train maintenance activities in depots and workshops the 3 AC train line can be supplied from anexternal source.
ln that case all the onboard auxiliary converters are first de-energized and disconnected from the 3 ACtrain line which is then supplied by the shore supply.The shore supply interfaces shall be compliantwith EN 50546.
5.2 Shore supply voltage characteristics
In most of the cases the shore supply source is connected to the 3 AC industrial grid via a 3 ACtransformer to adjust the output voltage at 40o v – 50 Hz.
The voltage quality in that case is fully defined by EN 50160.
However the shore supply source impedance will have to be determined to maintain the static voltagetolerances of the 3 AC train line within + 10 % and – 10 % as defined in 4.3 for the specified auxiliarypower.
Generally the required auxiliary power during the maintenance operations is reduced compared to theonboard 3 AC train line nominal auxiliary power in normal operation.
The TDR (Total Distortion Ratio) of the shore supply will be maintained below 10 % by use of anappropriate filter if necessary.
5.3 Shore supply general features
For protection aspect and according to UIC 554-1 the 3 AC 400 v-50 Hz from the shore supply shallbe floating and isolated from the industrial power grid. This way to proceed avoids any groundcirculating current if the on board 3 AC train line is not floating (e.g. neutral connected to ground).
The 3 AC 400V-50 Hz from the shore supply will be connected to the train line by means of a 3 ACcontactor.Consequently the AC loads permanently connected to the train line have to be able towithstand the voltage step with no ramp up without causing any disorder on board as an overcurrent.
NOTE A monitoring and protection system should ensure that the 3 AC train line cannot be energized at the same time by theonboard auxiliary converter system and the shore supply.