Braking chopper

Braking choppers, sometimes also referred to as Braking units, are used in the DC voltage intermediate circuits of frequency converters to control voltage when the load feeds energy back to the intermediate circuit.

This arises, for example, when a magnetized motor is being rotated by an overhauling load and so functions as a generator feeding power to the DC voltage intermediate circuit.

[1][2] They are an application of the chopper principle, using the on-off control of a switching device.

With DTC the inverter is directly controlled to achieve the desired torque and flux for the motor.

In other words, flux braking is most effective in a low power motor.