DEVICE AND METHOD FOR CONTROLLING ROTATIONAL SPEED OF SYNCHRONOUS RELUCTANCE MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a rotational speed controller for synchronous reluctance motor that can perform rotor-position detecting sensor-less speed control on a synchronous reluctance motor so that the degree of precision of the speed control may be maintained against load variation in both low-speed and high-speed regions. SOLUTION: The rotating speed controller includes a stopping/synchronizing coordinate transforming section 42 which outputs signals to second and third comparators 33 and 35, and a magnetic flux observing section 43 after detecting a two-phase current and an actual magnetic flux from a three-phase current outputted to the synchronous reluctance motor 41 and the magnetic flux observing section 43 which outputs a magnetic flux upon receiving the outputted two-phase current and two component voltages of a stopping coordinate system outputted from a synchronizing/stopping coordinate transforming section 38. This controller also includes a position estimating section 45 which estimates the magnetic flux angle and rotational speed of the rotor of the motor 41 required for controlling the motor 41 to a high speed by utilizing the outputted magnetic flux, and a low-speed control section 44 which estimates the magnetic flux angle of the rotor required for controlling the motor 41 to a low speed and outputs the estimated magnetic flux angle to the transforming section 38.