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DC bus and chopper

A full-load descent charges the DC bus: no braking, a chopper and resistor, or an active front end.

Lesson: Torque at zero speed, braking resistor or regeneration
Try it: the DC bus during a full-load descent

The 60 A chopper sets a floor of 12.7 Ω.

  • DC bus voltage
  • Over-voltage trip (800 V)
  • Regenerated power
  • Power in the resistor

The chopper holds the bus below the trip level: the energy becomes heat in the resistor.

Peak regenerated power
16.4 kW
Peak bus voltage
766 V
Energy burned
87.7 kJ
Chopper current
21.7 A

P = V² / R : 760² / 35 = 16.5 kW