Title:
MOTOR DRIVE SYSTEM AND METHOD
Document Type and Number:
Japanese Patent JP2022144938
Kind Code:
A
Abstract:
To provide a motor drive system capable of accurately estimating the rotation speed of a motor without being affected by the length of a secondary time constant of the motor in free-run restart.SOLUTION: A motor drive system that free-runs and restarts a motor using an inverter that drives the motor without a speed sensor includes a current detection unit that detects a drive current with which the inverter drives the motor, a rotational speed estimation unit that estimates the rotational speed of the motor on the basis of the drive current detected by the current detection unit, an inverter frequency control unit that variably generates an inverter frequency, and an inverter control unit that controls inverter switching without a speed sensor. The inverter frequency control unit sweeps the inverter frequency when the motor is free-running restarted, stops sweeping when the estimated rotational speed and the inverter frequency are synchronized, and sets a magnetic flux command value, which is the control command value for the motor magnetic flux to a specified value.SELECTED DRAWING: Figure 1
Inventors:
SUMIDA SATOSHI
KOJIMA TETSUO
KOJIMA TETSUO
Application Number:
JP2021046143A
Publication Date:
October 03, 2022
Filing Date:
March 19, 2021
Export Citation:
Assignee:
HITACHI LTD
International Classes:
H02P21/34; H02P5/46; H02P21/18; H02P21/24
Attorney, Agent or Firm:
Patent Business Corporation Sunnext International Patent Office
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