Predictive brush control for separately excited electric motors

A separately excited electric motor, comprising:

• a brush unit with partial brushes, each of which is configured to move towards a commutator via an adjusting mechanism driven by an adjusting motor to reversibly establish an electrical contact between partial brush and commutator, or to move away from the commutator to reversibly interrupt an electrical contact between partial brush and commutator, wherein the brush unit is connected to a control unit which is set up to control the adjusting motors in such a way that only a minimum contact surface between the entirety of the partial brushes and the commutator is provided that is required to reach a predicted, imminent operating point of the electric motor.