For years now, the field of train traction has been powered by switch mode inverters, driving the motor or auxiliary power circuits. There are two main application for aluminium electrolytic capacitors, as traction drives used to control the speed of large electrical motors and as auxiliary power supplies in rolling stock ( air conditioning).
Aside from functioning as a filter to block high-frequency components from disturbing the board net, they are used as an energy buffer to guarantee stable operation of the switch mode inverter driving the motor or supplementary power circuit.
To select the right kind of capacitor for this application you should mind to the following key criterions:
  1. needed ripple current
  2. maximized operating life
  3. low inductance
  4. extremely good resistance to vibrations
Moreover, forced cooling, locating capacitor in the coolest spot or mounting on a heatsink will maximize operating life, especially combined with the extended cathode construction.
Kendeil offers a vast selection of electrolytic capacitor to withstand this kind of application, from the entry level K01, K02 families, to more performant K91, K92 and K21, K22 with a very low ESR and high ripple current, than our special K41, K42 geometrically designed to be vibration resistant. Also film capacitor series like K36 and K37 are usually employed in railway systems.
Don’t hesitate to contact our technical department asking further information.