Electronically commutated electric motor with harmonic compensation

An electrical power steering system for a vehicle, the system comprising:

• an electric motor, the electric motor including
• stator;
• a rotor;
• a control unit connected to the stator and configured to generate control signals for supplying stator coils of the stator with current for generating a rotating magnetic field,
• a rotor position sensor;
• and
• a current sensor configured to detect currents flowing in the stator coils and to generate a current signal representing the currents flowing in the stator coils,
• wherein the control unit comprises a processing unit configured to ascertain harmonics of an electromotive force and to generate a compensating control signal which compensates for the effect of the harmonics as a function of the current signal and a voltage supplied to the stator coils and a rotor position signal generated by the rotor position sensor, and wherein the processing unit is further configured to overlap the compensating control signal with the control signal, so that it is possible to compensate at least partially or completely for the effect of the harmonics and thus the torque ripple, and
• wherein the power steering system is configured to generate a steering torque which aids steering by means of the electric motor.

A brake booster for a vehicle including an electric motor, having a stator and a rotor, wherein the electric motor comprises a control unit connected to the stator, wherein the control unit is configured to generate control signals for supplying stator coils of the stator with current for generating a rotating magnetic field, and wherein the electric motor is configured to at least partially compensate for a torque ripple of a torque generated by the rotor,

• wherein the electric motor includes a rotor position sensor and a current sensor, wherein the current sensor is configured to detect currents flowing in the stator coils and to generate a current signal representing the currents flowing in the stator coils,
• wherein the control unit comprises a processing unit, wherein the processing unit is configured to ascertain harmonics of an electromotive force and to generate a compensating control signal which compensates for the effect of the harmonics as a function of the current signal and a voltage supplied to the stator coils and a rotor position signal generated by the rotor position sensor, and wherein the processing unit is further configured to overlap the compensating control signal with the control signal, so that it is possible to compensate at least partially or completely for the effect of the harmonics and thus the torque ripple, and
• wherein the brake booster is configured to generate a braking force which aids braking by means of the electric motor.

An electric bicycle including an electric motor, the electric motoring including

• a stator;
• a rotor,
• a control unit connected to the stator and configured to generate control signals for supplying stator coils of the stator with current for generating a rotating magnetic field;
• a rotor position sensor;
• and
• a current sensor,
• wherein the current sensor is configured to detect currents flowing in the stator coils and to generate a current signal representing the currents flowing in the stator coils,
• wherein the control unit includes a processing unit configured to ascertain harmonics of an electromotive force and to generate a compensating control signal which compensates for the effect of the harmonics as a function of the current signal and a voltage supplied to the stator coils and a rotor position signal generated by the rotor position sensor, and wherein the processing unit is further configured to overlap the compensating control signal with the control signal, so that it is possible to compensate at least partially or completely for the effect of the harmonics and thus the torque ripple, and
• wherein the electric motor is a drive motor of the electric bicycle.