Abstract: Methods and apparatus for compensating for non-sinusoidal BEMF signals in an electrical motor using amplitudes, phases and orders of BEMF harmonic components and amplitude of 1st harmonic of BEMF of the electrical motor. First and second corrective components for vd and vq of the d-q coordinate system for the motor can be generated from amplitudes of the BEMF harmonic components and the angles of the BEMF harmonic components orders of the BEMF harmonic components and amplitude of 1st harmonic of BEMF.

Abstract: A method comprising: receiving a first current measurement that is taken at a first predetermined time instant; receiving a second current measurement that is taken at a second predetermined time instant; classifying the first current measurement as corresponding to one of a plurality of electrical signals, the first current measurement being classified based, at least in part, on a duty cycle pattern of the plurality of electrical signals; classifying the second current measurement as corresponding to another one of the plurality of electrical signals, the second current measurement being classified based, at least in part, on the duty cycle pattern of the plurality of electrical signals; and adjusting a duty cycle of at least one of the electrical signals based on the first current measurement, the classification of the first current measurement, the second current measurement, and the classification of the second current measurement.