Abstract: A system and method for estimating a power output of an electric motor with at least one magnetic field sensor includes providing magnetic field signal data, providing magnetic field frequency data based on the magnetic field signal data, determining a fundamental harmonic frequency of the supply frequency and at least one further frequency, determining a ratio between an amplitude of the at least one further harmonic frequency and an amplitude of the fundamental harmonic frequency, providing reference ratio data describing a relation of a ratio between an amplitude of the at least one further harmonic frequency and an amplitude of the fundamental harmonic frequency and a power output of the electric motor, and estimating the power output of the electric motor based on the reference ratio data and the determined ratio.

Abstract: A method and apparatus for self-commissioning a bearingless-motor drive, which includes a bearingless motor and a control unit of the bearingless motor are disclosed. The motor includes at least one winding and at least one permanent magnet. The method includes generating a magnetic model, the magnetic model including a plurality of constant parameters; supplying, while the movable part remains standstill, to the at least one winding at least two unequal currents; measuring, with a magnetic sensor, flux linkages caused by said at least two unequal currents, respectively; calculating, with the magnetic model, flux linkages by inputting to the magnetic model current values equal to the currents supplied to the at least one winding; and fitting, with a least-squares fitting algorithm, at least one constant parameter in the magnetic model such that the difference between the measured and calculated flux linkages will be minimized.

Abstract: A method and apparatus for self-commissioning a bearingless-motor drive, which includes a bearingless motor and a control unit of the bearingless motor are disclosed. The motor includes at least one winding and at least one permanent magnet. The method includes generating a magnetic model, the magnetic model including a plurality of constant parameters; supplying, while the movable part remains standstill, to the at least one winding at least two unequal currents; measuring, with a magnetic sensor, flux linkages caused by said at least two unequal currents, respectively; calculating, with the magnetic model, flux linkages by inputting to the magnetic model current values equal to the currents supplied to the at least one winding; and fitting, with a least-squares fitting algorithm, at least one constant parameter in the magnetic model such that the difference between the measured and calculated flux linkages will be minimized.