Motor driving device

Patent metadata

Field	Value
Publication number	US-11424710-B2
Application number	US-202016945367-A
Country	US
Kind code	B2
Filing date	Jul 31, 2020
Priority date	Aug 6, 2019
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A motor driving device includes an acquisition unit configured to acquire multiple pieces of data in data acquisition periods having different lengths; a selection unit configured to select a piece of data from among the multiple pieces of data, based on timing at which a switching circuit switches switching devices; and a control unit configured to control the switching circuit based on the selected data.

First claim

What is claimed is:

1. A motor driving device comprising:
an inverter unit including a plurality of power device units respectively including switching devices, the inverter unit being configured to convert a direct-current voltage into a polyphase alternating-current voltage;
a switching circuit configured to switch the switching devices;
current sensors provided on lines configured to supply the polyphase alternating-current voltage to a motor;
a processor; and
a memory that stores instructions,
wherein the instructions when executed by the processor cause the motor driving device to:
acquire data indicating currents flowing in the lines, based on outputs of the current sensors, wherein the data to be acquired includes multiple pieces of data in data acquisition periods having different lengths;
select a piece of data from among the multiple pieces of data acquired, based on timing at which the switching circuit switches the switching devices;
perform at least first data acquisition and second data acquisition;
in the first data acquisition, sequentially acquire pieces of first data for each piece of which the data acquisition period is a first period, wherein timings to start the data acquisition period are time-sequentially shifted by a first time interval; and
in the second data acquisition, sequentially acquire pieces of second data for each piece of which the data acquisition period is a second period that is longer than the first period, wherein timings to start the data acquisition period are shifted by a second time interval,
wherein
the first time interval is shorter than the first period,
the second time interval is shorter than the second period, and
the first period and the second period are overlapping.

2. The motor driving device according to claim 1 , wherein the instructions, when executed by the processor, further cause the motor driving device to: select a piece of data from among multiple pieces of data that have been acquired in periods other than a given period in which a transient current flows in the lines due to the switching of the switching devices.

3. The motor driving device according to claim 1 , wherein the instructions, when executed by the processor, further cause the motor driving device to: select a piece of data from among multiple pieces of data that have been acquired in periods other than a given period in which a transient current flows in the lines due to the switching of the switching devices.

4. The motor driving device according to claim 2 , wherein the instructions, when executed by the processor, further cause the motor driving device to: select a latest piece of data from among the multiple pieces of data acquired in the periods other than the given period.

5. The motor driving device according to claim 3 , wherein the instructions, when executed by the processor, further cause the motor driving device to: select a latest piece of data from among the multiple pieces of data acquired in the periods other than the given period.

6. The motor driving device according to claim 4 , wherein, if there are multiple pieces of latest data among the multiple pieces of data acquired in the periods other than the given period, the instructions, when executed by the processor, further cause the motor driving device to select data acquired in a longest one of the data acquisition periods from among the multiple pieces of latest data.

7. The motor driving device according to claim 5 , wherein, if there are multiple pieces of latest data among the multiple pieces of data acquired in the periods other than the given period, the instructions, when executed by the processor, further cause the motor driving device to select data acquired in a longest one of the data acquisition periods from among the multiple pieces of latest data.

8. The motor driving device according to claim 1 , wherein, if a first timing corresponding to completion of acquisition of a latest piece of the first data among multiple pieces of the first data that have been acquired in periods other than a given period in which a transient current flows in the lines due to the switching of the switching devices is after a second timing corresponding to completion of acquisition of a latest piece of the second data among multiple pieces of the second data that have been acquired in periods other than the given period, and if a time difference between the first timing and the second timing is less than a threshold, the instructions, when executed by the processor, further cause the motor driving device to select the latest piece of the second data.

9. A method for controlling a motor driving device, the method comprising:
acquiring data indicating currents flowing in lines, based on outputs of current sensors, wherein the data to be acquired includes multiple pieces of data in data acquisition periods having different lengths, wherein the current sensors are provided on the lines that are configured to supply polyphase alternating-current voltage to a motor;
selecting a piece of data from among the multiple pieces of data acquired, based on timing at which a switching circuit switches switching devices, wherein the switching circuit is configured to switch the switching devices of a power device unit of an inverter unit, wherein the inverter unit is configured to convert a direct-current voltage into the polyphase alternating-current voltage;
performing at least first data acquisition and second data acquisition;
in the first data acquisition, sequentially acquiring pieces of first data for each piece of which the data acquisition period is a first period, wherein timings to start the data acquisition period are time-sequentially shifted by a first time interval; and
in the second data acquisition, sequentially acquiring pieces of second data for each piece of which the data acquisition period is a second period that is longer than the first period,

wherein timings to start the data acquisition period are shifted by a second time interval,
wherein
the first time interval is shorter than the first period,
the second time interval is shorter than the second period, and
the first period and the second period are overlapping.

10. The method according to claim 9 , the method further comprising selecting a piece of data from among multiple pieces of data that have been acquired in periods other than a given period in which a transient current flows in the lines due to the switching of the switching devices.

11. The method according to claim 9 , the method further comprising selecting a piece of data from among multiple pieces of data that have been acquired in periods other than a given period in which a transient current flows in the lines due to the switching of the switching devices.

12. The method according to claim 10 , the method further comprising selecting a latest piece of data from among the multiple pieces of data acquired in the periods other than the given period.

13. The method according to claim 12 , the method further comprising selecting a latest piece of data from among the multiple pieces of data acquired in the periods other than the given period.

14. The method according to claim 13 , wherein, if there are multiple pieces of latest data among the multiple pieces of data acquired in the periods other than the given period, the instructions, when executed by the processor, further cause the motor driving device to select data acquired in a longest one of the data acquisition periods from among the multiple pieces of latest data.

15. The method according to claim 14 , wherein, if there

Assignees

• Fanuc Corp

Inventors

• Tateda Masaya
• Matsumoto Yasuyuki

Classifications

• H02P27/06

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02P23/14 Primary

  Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage · CPC title

• H02P11/04

  for controlling dynamo-electric converters having a DC output · CPC title

• G01R31/50

  Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58) · CPC title

• H02P27/08 Primary

  with pulse width modulation · CPC title