Patent ID: 6081093
Filing Date: 2000-06-27
Classification: H02P

Abstract:
A sensorless control method of a permanent magnet synchronous motor wherein a permanent magnet synchronous motor having a permanent magnet as a rotor is controlled in a region from zero speed to high speed continuously,characterized in that in the .alpha.-.beta. space coordinate system where one phase is made .alpha. axis and the forward rotating direction in the electric angle 90.degree. from the .alpha. axis is made .beta. axis, the coordinate d-q axis rotating in the real motor rotation speed .omega..sub.R is set where the magnetic axis of the motor is made d and the axis of leading in 90.degree. from the d-axis is made q, and the .gamma.-.delta. axis is set where the assigned magnetic axis of the motor is made .gamma. and the axis leading in 90.degree. from the .gamma. axis is made .delta., andthat when the rotation speed .omega..sub.R.sbsb..gamma. of the .gamma.-.delta. axis is determined, the distribution gain K1 is set so as to be decreased as the absolute value of the rotation speed command .omega..sub.RREF becomes large and the distribution gain K2 is set so as to be increased as the absolute value of the rotation speed command .omega..sub.RREF becomes large, and the rotation speed command .omega..sub.RREF is multiplied by K1 and the speed estimated value .omega..sub.RP determined from the induced voltage of the synchronous motor or the induced voltage estimated value is multiplied by K2 respectively, and both multiplied values are summed thereby the rotation speed .omega..sub.R.sbsb..gamma. of the .gamma.-.delta. axis of the assigned magnetic axis is determined.