Method of estimating rotational position of motor, and control apparatus of motor

摘要

A method of estimating a rotational position of a motor having saliency includes the steps of a) superimposing, on a drive voltage to rotate a rotating portion of the motor, a measuring voltage having a predetermined frequency higher than a frequency of the drive voltage to generate a plurality of voltages, and supplying the plurality of voltages to a stationary portion of the motor; b) in parallel with step a), extracting a component of the predetermined frequency in a current flowing in the stationary portion as an extracted current; c) calculating a sum of squares of the extracted current and a phase-shifted current obtained by shifting a phase of the extracted current by π/2 to acquire a composite signal related to an amplitude of the extracted current; and d) acquiring a rotational position of the rotating portion based on the composite signal.

主权项

1. A method of estimating a rotational position of a motor having saliency, the method comprising the steps of:
a) superimposing, on a drive voltage to rotate a rotating portion of the motor, a measuring voltage having a predetermined frequency higher than a frequency of the drive voltage to generate a plurality of voltages, and supplying the plurality of voltages to a stationary portion of the motor; b) in parallel with step a), extracting a component of the predetermined frequency in a current flowing in the stationary portion as an extracted current; c) calculating a sum of squares of the extracted current and a phase-shifted current obtained by shifting a phase of the extracted current by π/2 to acquire a composite signal related to an amplitude of the extracted current; and d) acquiring a rotational position of the rotating portion based on the composite signal.