AC motor speed sensorless control device

摘要

PPROBLEM TO BE SOLVED: To provide a speed sensorless controller for AC motor which keeps the stability of control even in a low-speed regeneration state and also is robust. PSOLUTION: This speed sensorless controller for AC motor includes a current detector 14, a voltage command operator 6 that calculates the primary voltage command to the AC motor 13, a magnetic flux estimator that estimates the magnetic flux of a motor together with the primary current of the AC motor 13 using a primary current detected value and a primary voltage command, a speed estimator that estimates the speed using the magnetic flux of the motor, and a speed control unit 2 that computes a torque current command by performing speed control based on the deviation between the speed command and the speed estimate. Further, the controller includes a voltage compensator 10 which compensates the primary voltage command being the input value of the magnetic flux estimator, using the primary current estimate estimated with the magnetic flux estimator and the primary current detected value being the output value of the current detector 14. PCOPYRIGHT: (C)2008,JPO&INPIT