Control system for synchronous motor including abnormality detection and diagnosis function

摘要

A control system includes a current control unit providing, in accordance with the magnetic pole position of a rotor in which permanent magnets are disposed, a first current command to a first excitation phase of a stator winding and providing a second current command to a second excitation phase, a current error calculator calculating a current error which is a difference between a current flowing through the motor during the first period and the first current command or a difference between a current flowing through the motor during the second period and the second current command, and an abnormality detection and diagnosis unit detecting an abnormality based on the speed, the direction of movement and the amount of movement of the motor and the magnitude of the current error.

主权项

1. A control system for a synchronous motor with an abnormality detection and diagnosis function, the control system comprising:
a current control unit providing, in detection of a magnetic pole position of a rotor of a motor during the initial start-up of the motor in which permanent magnets are disposed, a first current command to a first excitation phase of a stator winding of the motor over a first period of time when the motor is to be stopped and providing a second current command to a second excitation phase different from the first excitation phase over a second period of time when the motor is to be caused to operate; a magnetic pole position detector correcting an excitation phase on the basis of a magnetic pole position of the stopped motor; a current error calculator calculating a current error, the current error being a difference between a current flowing through the motor in the second period of time and the second current command; and an abnormality detection and diagnosis unit detecting an abnormality on the basis of
a speed of the motor in the first period of time, andthe speed of the motor, the direction of movement and the amount of movement of the motor, and the magnitude of the current error in the second period of time, wherein when the speed of the motor is higher than a predetermined speed while the first current command is provided to the first excitation phase of the motor over the first period of time, the abnormality detection and diagnosis unit judges that a first abnormality has occurred in a current feedback from the motor to the current control unit or in a speed feedback from the motor to the abnormality detection and diagnosis unit.