I am designing a bidirectional DC-DC converter to charge and discharge batteries on a DC bus. The power of this converter is 50 kW and the average current in the inductor (the same as that on the battery) is 125 A. By designing the converter for a 20% current ripple I will have iL_min = 112.5 A and iL_max = 137.5 A. The frequency switch is 25kH. I wonder if this ripple of 25 A current is harmful to the battery bank.

  • \$\begingroup\$ We would need more information about your battery bank. \$\endgroup\$ – evildemonic Aug 3 '18 at 15:34
  • \$\begingroup\$ I think you need to have capacitors in parallel with the battery anyway, because otherwise, in the event of a disconnect while charging, you will have voltage over-shoot and possible system failure. If the cap ESR is less than the battery ESR, the capacitor will shunt the ripple current and the battery will never see it. You will have to deal with inrush at the moment of connection somehow. \$\endgroup\$ – mkeith Aug 3 '18 at 16:12
  • \$\begingroup\$ @evildemonic I'm just designing the converter. You could suggest an array of lithium batteries to supply 50kW at a voltage of 400V (input voltage of the converter) \$\endgroup\$ – Storage Aug 3 '18 at 16:31
  • \$\begingroup\$ @mkeith Your information is completely amazing, could you tell me where I could learn more about this and get more technical information like that? \$\endgroup\$ – Storage Aug 3 '18 at 16:32
  • \$\begingroup\$ Are you going to build and test this converter? Have you ever built and tested a high voltage, high-power DC-DC converter before? \$\endgroup\$ – mkeith Aug 4 '18 at 0:07

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