Datasheet
RUW15 Series
Isolated Ultra-Wide Input DC/DC Converters
KDC_RUW15.B02 Page 5 of 13
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SURGE SUPPRESSION
EN50155/RIA12 surge/dip compliance
DC/DC power converters connected to the battery voltage or other low voltage source in railway rolling stock commonly have to comply with the requirements of
European standard EN 50155:2007. This standard defines a range of nominal battery voltages that may be encountered with possible fluctuations and interruptions.
Nominal voltages (Un) are 24V, 48V, 72V, 96V and 110VDC with tolerances of -30/+25%. Fluctuations can take the nominal voltages up +40% for one second and down
-40% for 100ms. The possible total range of nominals and fluctuations is therefore 14.4V to 154V (24V -40% to 110V +40%). Other national variations include US rail
nominal battery voltages of 37V and 74V; higher surges of 1.5 x Un for one second and 3.5 x Un for 20ms found in the UK standard RIA12 and lower dips to 12V for
100ms found in the French standard NF F 01-510.
Figure 1 summarises this. The ranges of voltages for the French standard NF F 01-510 and for the USA are also shown for information. Additionally, according to EN
50155, complete interruptions of the supply can last for up to 10ms (Class S2) or 30ms during supply changeover (Class C2).
Figure 1 - Summary of nominal voltages and variations for rail applications
Tables 1, 2 and 3 show how the RUW15 can be configured to cover all of these requirements:
Table 1 - RIA12 SURGES AND TRANSIENTS
Nominal
Input
Input
range
Brown-out
100ms
(0.6xVin)
Transient
1s (1.5xVin)
Transient
20ms
(3.5 x Vin)
Solution
24 V
16.6 -
30V
14.4V 36V 84V RUW15H
37.5 V 26 - 47V 22.5V 56.25V 131.25V RUW15
48 V
33.6 -
60V
28.8V 72V 168V RUW15
72 V
50.4V -
90V
43.2V 112.5V 252V
RUW15
+ limiter
96 V
67.2 -
120V
57.6V 144V 336V
RUW15
+ limiter
110 V
77 -
137.5V
66V 165V 385V
RUW15
+ limiter
Table 2 - EN50155 SURGES AND TRANSIENTS
Nominal
Input
Input range
Brown-out
100ms
(0.6xVin)
Transient 1s
(1.4xVin)
Solution
24 V 16.6 - 30 V 14.4 V 33.6 V RUW15H
37.5 V 26 - 47 V 22.5 V 52.5 V RUW15
48 V 33.6 - 60 V 28.8 V 67.2 V RUW15
72 V 50.4V - 90 V 43.2 V 100.8 V RUW15
96 V 67.2 - 120 V 57.6 V 134.4 V RUW15
110 V 77 - 137.5 V 66 V 154 V RUW15