DRIVE UNIT OF SYNCHRONOUS MOTOR

• US 20150222215A1
• Filed: 09/03/2012
• Published: 08/06/2015
• Est. Priority Date: 09/03/2012
• Status: Active Grant

• Current Assignee: Toshiba Mitsubishi-Electric Industrial Systems Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Mitsubishi-Electric Industrial Systems Corporation (Toshiba Corporation)
• Inventors: Ishida, Takashi
• Granted Patent: US 9,948,223 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02P 21/10 Direct field-oriented control; Rotor flux feed-back control
• CPC Class Codes: H02P 21/141 Flux estimation
• CPC Class Codes: H02P 25/024 controlled by supply frequency

Abstract

Provided is drive unit of a synchronous motor capable of improving the accuracy of magnetic flux operations with a simple configuration. To this end, the drive unit has a magnetic flux operation part which, in the case where a direction of a magnetic field pole of the synchronous motor is regarded as a d-axis and a direction orthogonal to the d-axis is regarded as a q-axis, calculates a magnetic flux of the d-axis and a magnetic flux of the q-axis on the basis of a current of the d-axis, a current of the q-axis, and a field current of the synchronous motor; and a magnetic flux operation error correcting part which calculates a phase difference between an input voltage and an input current of the synchronous motor and corrects an inner-phase difference angle calculated from the magnetic flux of the d-axis and the magnetic flux of the q-axis on the basis of the phase difference.

Claims

1. A drive unit of a synchronous motor comprising:

a magnetic flux operation part which, in the case where a direction of a magnetic field pole of the synchronous motor is regarded as a d-axis and a direction orthogonal to the d-axis is regarded as a q-axis, calculates a magnetic flux of the d-axis and a magnetic flux of the q-axis on the basis of a current of the d-axis, a current of the q-axis, and a field current of the synchronous motor; and

a magnetic flux operation error correcting part which calculates a phase difference between an input voltage and an input current of the synchronous motor and corrects an inner-phase difference angle calculated from the magnetic flux of the d-axis and the magnetic flux of the q-axis on the basis of the phase difference.

2. The drive unit of the synchronous motor according to claim 1, wherein the magnetic flux operation error correcting part calculates the phase difference on the basis of an input voltage reference and an input current detection value of the synchronous motor.

3. The drive unit of the synchronous motor according to claim 1, wherein the magnetic flux operation error correcting part calculates the phase difference on the basis of an input voltage detection value and an input current detection value of the synchronous motor.

4. The drive unit of the synchronous motor according to claim 1, wherein the magnetic flux operation error correcting part corrects a magnetic flux of the q-axis on the basis of a magnetic flux of the d-axis, a magnetic flux of the q-axis, and a corrected inner-phase difference angle so that the size of a main magnetic flux becomes identical before and after a correction.