| 摘要 |
PROBLEM TO BE SOLVED: To provide a sensorless drive device of a synchronous motor which allows for shockless switching of a control method of an inverter.SOLUTION: A sensorless drive device of a synchronous motor includes: change-over switches 106, 115, 114a for switching from V/f constant control to sensorless vector control when a speed estimation value of a synchronous motor SM exceeds a speed reference value; a d-axis current regulator 111 generating a d-axis voltage command value from a d-axis current command value common to both control times; a q-axis current regulator 107 generating a q-axis voltage command value from a q-axis current command value of zero during V/f constant control, and generating a q-axis voltage command value from the speed deviation during sensorless vector control; acceleration deceleration calculation means outputting an acceleration deceleration calculation value generated from the speed command value during V/f constant control; and a speed estimator 114 generating a gradually changing speed estimation value by using the acceleration deceleration calculation value used during V/f constant control as an initial value, during sensorless vector control. |
