Motor controller and construction machine provided therewith

Patent metadata

Field	Value
Publication number	US-9287808-B2
Application number	US-201414289957-A
Country	US
Kind code	B2
Filing date	May 29, 2014
Priority date	May 30, 2013
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

There is obtained a configuration capable of rapidly decelerating a motor even if a failure occurs in the communication between a controller and a motor control unit in a motor controller in which a speed command is input from the controller to the motor control unit. A motor controller 1 is provided with a main controller 2 , and a motor control unit 3 configured to be communicable with the main controller 2 to drive a motor M according to a torque command output from the main controller 2 . The motor control unit 3 includes a speed control unit 31 for outputting a torque command, so as to decelerate the motor M, if any failure occurs in communication with the main controller 2 while the motor M is being driven.

First claim

What is claimed is:

1. A motor controller comprising:
a controller; and
a motor control unit configured to be capable of communicating with the controller to drive a motor according to a drive command output from the controller, the motor control unit including a deceleration controller for outputting a drive command, so as to decelerate the motor, if any failure occurs in communication with the controller while the motor is being driven
a communication failure detector for detecting a failure in communication with the controller; and
a command selector for selecting a drive command output from the controller as a drive command for the motor if any communication failure is not detected by the communication failure detector, or selecting a drive command output from the deceleration controller as a drive command for the motor if a communication failure is detected by the communication failure detector.

2. The motor controller according to claim 1 , wherein the deceleration controller performs regenerative operation on the motor so as to decelerate the motor.

3. The motor controller according to claim 1 , wherein the drive command is a torque command, and the motor control unit further includes a torque limiter for limiting the torque command to a predetermined value or smaller, the torque limiter being configured to, in at least part of a rotational speed range in the regenerative operation region of the motor, make the predetermined value lower than a torque limiting value at the time of normal control of the motor, if any communication failure is detected by the communication failure detector.

4. A construction machine comprising:
a motor controller according to claim 1 ; and
a motor controlled by the motor controller.

Assignees

• Sinfonia Technology Co Ltd
• Kobelco Constr Mach Co Ltd

Inventors

• Ito Takeo
• Moriya Hideaki
• Tomizaki Takeshi
• Nakazumi Akira
• Kamimura Yusuke

Classifications

• H02P21/36

  Arrangements for braking or slowing; Four quadrant control · CPC title

• H02P3/18 Primary

  for stopping or slowing an AC motor · CPC title

• H02P29/027 Primary

  the fault being an over-current · CPC title

• H02P21/0092

  Electricity · mapped topic

• H02P29/024

  Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load · CPC title