Motor control device

Patent metadata

Field	Value
Publication number	US-9941823-B2
Application number	US-201615138222-A
Country	US
Kind code	B2
Filing date	Apr 26, 2016
Priority date	Oct 30, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

This disclosure discloses a motor control device configured to control a motor. The motor control device includes an inverter part, a gate driving circuit, a PWM generation circuit, at least one gate buffer, and a control part. The inverter part is configured to convert direct current into alternate current in response to a motor drive command. The gate driving circuit is configured to drive the inverter part. The PWM generation circuit is configured to generate a PWM signal applied to the gate driving circuit. The at least one gate buffer is disposed between the gate driving circuit and the PWM generation circuit. The control part is configured to apply a test signal to the gate buffer to determine abnormality of the gate buffer.

First claim

What is claimed is:

1. A motor control device configured to control a motor, comprising:
an inverter part configured to convert direct current into alternate current in response to a motor drive command;
a gate driving circuit configured to drive the inverter part;
a PWM generation circuit configured to generate a PWM signal applied to the gate driving circuit;
at least one gate buffer disposed between the gate driving circuit and the PWM generation circuit; and
a control part configured to apply a test signal to the gate buffer to determine abnormality of the gate buffer,
wherein the at least one gate buffer comprises:
a PWM signal input part configured to receive the PWM signal;
a PWM signal output part configured to output the PWM signal received by the PWM signal input part;
a diagnosis signal input part configured to receive the test signal;
a diagnosis signal output part configured to output a diagnosis signal based on the test signal received by the diagnosis signal input part; and
a switch control signal input part configured to receive a switch control signal for switching a conduction state or a blocking state of the PWM signal at the gate buffer, and

wherein the control part comprises a diagnosis part configured to output the test signal that dynamically changes to the diagnosis signal input part of the gate buffer, configured to receive the diagnosis signal output from the diagnosis signal output part, and configured to determine that the abnormality has occurred in the gate buffer when the diagnosis signal is kept at a substantially constant level and the switch control signal is in a state corresponding to the conduction state of the PWM signal at the gate buffer.

2. The motor control device according to claim 1 ,
wherein the control part comprises:
a switch control signal branch input part configured to branch and receive the switch control signal.

3. The motor control device according to claim 2 ,
wherein a state as a conduction state or a blocking state between the diagnosis signal input part and the diagnosis signal output part have a same state as between the PWM signal input part and the PWM signal output part based on the switch control signal.

4. The motor control device according to claim 3 ,
wherein the at least one gate buffer comprises a plurality of gate buffers.

5. The motor control device according to claim 4 ,
wherein each of the gate buffers comprises
a functional state signal output part configured to output a functional state signal corresponding to the switch control signal and corresponding to the conduction state and the blocking state between the PWM signal input part and the PWM signal output part in the gate buffer, and

the motor control device further comprising
a logical product circuit configured to output logical product of the functional state signals output from the functional state signal output parts of each of the gate buffers.

6. The motor control device according to claim 5 ,
wherein the control part is configured to output the test signal as a periodical signal.

7. The motor control device according to claim 6 ,
wherein the periodical signal includes a pulse waveform signal.

8. The motor control device according to claim 7 , further comprising
an inverter circuit part configured to invert a waveform of a signal, the inverter circuit part disposed at either one of a signal line between the control part and the diagnosis signal input part of the gate buffer, or a signal line between the control part and the diagnosis signal output part of the gate buffer,
wherein the diagnosis part is configured to determine that a short has occurred between the signal lines when the waveforms of the signals correspond with each other.

9. The motor control device according to claim 1 , wherein the control part is configured to apply the test signal as a regularly repeating signal.

10. The motor control device according to claim 9 , wherein the control part is configured to regularly repeat the test signal continuously during operation of the motor control device.

11. The motor control device according to claim 1 , further comprising
an inverter circuit part configured to invert a waveform of a signal, the inverter circuit part disposed at either one of a signal line between the control part and the diagnosis signal input part of the gate buffer, or a signal line between the control part and the diagnosis signal output part of the gate buffer,
wherein the diagnosis part is configured to determine that a short has occurred between the signal lines when the waveforms of the signals correspond with each other.

12. The motor control device according to claim 1 , further comprising:
a monitor part formed by a logical product circuit in communication with the at least one gate buffer,
wherein the at least one gate buffer includes a functional state signal output part configured to output a functional state signal that corresponds to the switch control signal to the monitor part, the monitor part being configured to output a logical product based on the functional state signal.

13. The motor control device according to claim 1 , further comprising:
a photo coupler configured to receive a stop input signal and configured to output the switch control signal.

14. The motor control device according to claim 13 ,
wherein the control part comprises:
a switch control signal branch input part configured to branch and receive the switch control signal, the switch control signal branch input part including an alarm reporting part configured to determine whether a malfunction has occurred in the photo coupler.

15. The motor control device according to claim 14 ,
wherein the switch control signal is input to the alarm reporting part and to the switch control signal input part of the at least one gate buffer.

Assignees

• Yaskawa Electric Corp

Inventors

• Hisamatsu Junya
• HIROMI Taishi
• Tanaka Yusuke

Classifications

• H02M1/38

  Means for preventing simultaneous conduction of switches · CPC title

• H02P6/28

  Arrangements for controlling current (H02P6/10 takes precedence) · CPC title

• H02M1/32

  Means for protecting converters other than automatic disconnection · CPC title

• H02H7/1225

  responsive to internal faults, e.g. shoot-through (avoiding shoot-through H02M1/38) · CPC title

• H02M1/082

  with digital control · CPC title