Matrix converter and method for determining constants of alternating-current motor

Patent metadata

Field	Value
Publication number	US-10110139-B1
Application number	US-201715787006-A
Country	US
Kind code	B1
Filing date	Oct 18, 2017
Priority date	Apr 21, 2017
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A matrix converter includes a power converter circuit connectable on one side thereof with an alternating-current supply via a high-frequency filter and connectable on another side thereof with an alternating-current motor; a snubber circuit connected with a one-side line for connecting the high-frequency filter and the power converter circuit; a discharge switch discharging a charge accumulated in the snubber circuit depending on a voltage of the snubber circuit; and a control circuit configured to execute controlling the power converter circuit on the basis of a carrier frequency in test such that a test voltage is applied to the alternating-current motor, changing the carrier frequency in test on the basis of an operation state of the discharge switch, and determining constants of the alternating-current motor on the basis of a response state of the alternating-current motor at the time when the test voltage is applied.

First claim

What is claimed is:

1. A matrix converter comprising:
a power converter circuit performing bidirectional power conversion between one side and another side thereof, the power converter circuit being connectable on the one side thereof with an alternating-current supply via a high-frequency filter and connectable on the other side thereof with an alternating-current motor;
a snubber circuit connected with a one-side line for connecting the high-frequency filter and the power converter circuit;
a discharge switch discharging a charge accumulated in the snubber circuit depending on a voltage of the snubber circuit; and
a control circuit configured to execute controlling the power converter circuit on the basis of a carrier frequency in test such that a test voltage is applied to the alternating-current motor, changing the carrier frequency in test on the basis of an operation state of the discharge switch, and determining a constant of the alternating-current motor on the basis of a response state of the alternating-current motor at a time when the test voltage is applied.

2. The matrix converter according to claim 1 , wherein
the control circuit is configured to change the carrier frequency in test in a range lower than a carrier frequency in drive.

3. The matrix converter according to claim 2 , wherein
the control circuit is configured to change the carrier frequency in test in such a way as to search for a frequency at which the discharge switch is not in an on-state, the frequency being closer to a resonant frequency of the high-frequency filter.

4. The matrix converter according to claim 3 , wherein
the control circuit is configured to change the carrier frequency in test in a range higher than the resonant frequency of the high-frequency filter.

5. The matrix converter according to claim 3 , wherein
the control circuit is configured to change the carrier frequency in test to set the carrier frequency in test farther from the resonant frequency of the high-frequency filter until the discharge switch enters an off-state.

6. The matrix converter according to claim 4 , wherein
the control circuit is configured to change the carrier frequency in test to set the carrier frequency in test farther from the resonant frequency of the high-frequency filter until the discharge switch enters an off-state.

7. A matrix converter comprising:
a power converter circuit performing bidirectional power conversion between one side and another side thereof, the power converter circuit being connectable on the one side thereof with an alternating-current supply via a high-frequency filter and connectable on the other side thereof with an alternating-current motor;
a snubber circuit connected with a one-side line for connecting the high-frequency filter and the power converter circuit;
a discharge switch discharging a charge accumulated in the snubber circuit depending on a voltage of the snubber circuit;
a test control means for controlling the power converter circuit on the basis of a carrier frequency in test such that a test voltage is applied to the alternating-current motor;
a carrier frequency setting means for changing the carrier frequency in test on the basis of an operation state of the discharge switch; and
a constant determining means for determining a constant of the alternating-current motor on the basis of a response state of the alternating-current motor at a time when the test voltage is applied.

8. The matrix converter according to claim 7 , wherein
the carrier frequency setting means is configured to change the carrier frequency in test in a range lower than a carrier frequency in drive.

9. The matrix converter according to claim 8 , wherein
the carrier frequency setting means is configured to change the carrier frequency in test in such a way as to search for a frequency at which the discharge switch is not in an on-state, the frequency being closer to a resonant frequency of the high-frequency filter.

10. The matrix converter according to claim 9 , wherein
the carrier frequency setting means is configured to change the carrier frequency in test in a range higher than the resonant frequency of the high-frequency filter.

11. The matrix converter according to claim 9 , wherein
the carrier frequency setting means is configured to change the carrier frequency in test to set the carrier frequency in test farther from the resonant frequency of the high-frequency filter until the discharge switch enters an off-state.

12. The matrix converter according to claim 10 , wherein
the carrier frequency setting means is configured to change the carrier frequency in test to set the carrier frequency in test farther from the resonant frequency of the high-frequency filter until the discharge switch enters an off-state.

13. A method for determining constants of an alternating-current motor using a matrix converter, the matrix converter comprising a power converter circuit performing bidirectional power conversion between one side and another side thereof, the power converter circuit being connectable on the one side thereof with an alternating-current supply via a high-frequency filter and connectable on the other side thereof with an alternating-current motor; a snubber circuit connected with a one-side line for connecting the high-frequency filter and the power converter circuit; and a discharge switch discharging a charge accumulated in the snubber circuit depending on a voltage of the snubber circuit, the method comprising:
controlling the power converter circuit on the basis of a carrier frequency in test such that a test voltage is applied to the alternating-current motor;
changing the carrier frequency in test on the basis of an operation state of the discharge switch; and
determining a constant of the alternating-current motor on the basis of a response state of the alternating-current motor at a time when the test voltage is applied.

Assignees

• Yaskawa Electric Corp

Inventors

• Hanada Toshihiro
• Akimoto Shinichi
• Imayoshi Hiroyuki
• Inoki Keisei

Classifications

• H02M5/27 Primary

  for conversion of frequency · CPC title

• H02P23/14 Primary

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

• H02P21/16

  Estimation of constants, e.g. the rotor time constant · CPC title

• H02M5/02

  without intermediate conversion into DC · CPC title

• H02M5/297

  for conversion of frequency · CPC title