Product category:
Batteries, chargers and circuit protection
News Release from: Saft Industrial Batteries | Subject: SRX batteries
Edited by the Engineeringtalk Editorial
Team on 29 July 2005
Batteries help keep tilting trains on
the level
Alstom Class 390 Pendolino EMU tilting trains rely on Saft SRX batteries to provide the vital power supply support through overhead line neutral sections.
Alstom Class 390 Pendolino EMU tilting trains, now in service with Virgin Trains on the West Coast Main Line, rely on Saft SRX batteries to provide the vital power supply support through overhead line neutral sections that ensures correct operation of their tilting mechanism as they travel at speeds of up to 200km/h By leaning into curves while maintaining full speed, the Pendolino tilting trains reduce travel times and provide greater passenger comfort without the need for specialised infrastructure
However, the electric actuators that tilt the trains require a considerable amount of power within a short period of time - typically a peak load of 20kW for around 1s.
In addition to powering the tilting mechanism through overhead line neutral sections, the onboard battery is required to support the remainder of the train control system during this period.
Furthermore, in the event of total power failure, it has to provide short term power support to the tilt mechanism, to maintain passenger comfort while the train speed is reduced, followed by a further 90min backup power for emergency lighting, communication and door opening systems.
Saft worked with Alstom to develop a fully integrated onboard rechargeable battery system capable of fitting into the available space under the floor of the train cars.
Each battery comprises 72 Saft SRX 1200P cells, with a nominal capacity of 115Ah, supplied ready to fit in a battery box complete with connector.
One battery is fitted to each of the nine cars of the 53 nine-car Pendolino train sets.
The SRX is a high power battery, developed specifically to deliver short duration high current discharges of up to 1min and up to five times its capacity, which makes it ideal for this type of application.
Discharges of up to three times capacity for up to 3min can also provide power for high speed train emergency braking.
The SRX operates over a wide temperature range, from -50 to +70C.
Even at -20C the SRX battery retains more than 70% capacity, this avoids the need to oversize the battery and ensures power availability at low temperatures.
The SRX design features sintered positive and plastic-bonded negative electrodes which make it significantly smaller and lighter than conventional batteries of similar performance, an important consideration for modern rolling stock which places a key emphasis on low weight for maximum energy efficiency.
In addition it is extremely reliable, it does not suffer the "sudden death" failure that can afflict lead acid batteries, and can provide a long service life of up to 15 years.
This extended lifetime exceeds the minimum lifetime required by the UIC 854 R railway specification by more than six times.
A further advantage of the SRX for Virgin Trains is that the battery will need no special attention between normal rolling stock maintenance examinations.
Topping up with distilled water is only required at two-year intervals, and there is no need to change the electrolyte during the battery's lifetime. Request a free brochure from Saft Industrial Batteries ...
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