Power converting device, motor driving device, and refrigerating and air-conditioning apparatus

Patent metadata

Field	Value
Publication number	US-9240736-B2
Application number	US-201114003286-A
Country	US
Kind code	B2
Filing date	Apr 8, 2011
Priority date	Apr 8, 2011
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

A power converting device includes; one or more backflow preventing elements that prevent electric current from flowing backward from a load side toward a power supply; a commutating unit for performing a commutation operation for causing electric current to flow toward a different path that is connected in parallel with the one or more backflow preventing elements; a malfunction detector for detecting a malfunction of the commutating unit; and a controller configured to control the commutating unit to perform commutation operation just before the recovery current flows through the backflow preventing element from the load side to the power supply and to perform operation control related to protection of the commutating unit on a basis of detection by the malfunction detector.

First claim

The invention claimed is:

1. A power converting device comprising:
one or more backflow preventing elements that prevent electric current from flowing backward from a load side toward a power supply;
a commutating unit for performing a commutation operation for causing electric current to flow toward a different path that is connected in parallel with the one or more backflow preventing elements;
a malfunction detector for detecting a malfunction of the commutating unit; and a controller configured to control the commutating unit to perform commutation operation just before a recovery current flows through the backflow preventing element from the load side to the power supply and to perform operation control related to protection of the commutating unit on a basis of detection by the malfunction detector,
wherein the commutating unit includes
a commutation rectifying element that rectifies the electric current flowing through the different path,
a transformer that performs the commutation operation by applying voltage based on voltage related to a primary winding to a secondary winding on the different path, and
a transformer driving unit that controls excitation current caused by application of voltage to the primary winding of the transformer.

2. The power converting device of claim 1 ,
wherein at least one rectifying element that constitutes the rectifying circuit that rectifies voltage related to the power supply serves as the one or more backflow preventing elements.

3. The power converting device of claim 2 ,
wherein the commutating unit includes
a commutation rectifying element that rectifies the electric current flowing through the different path,
a transformer that performs the commutation operation by applying voltage based on voltage related to a primary winding to a secondary winding on the different path, and
a transformer driving unit that controls excitation current caused by application of voltage to the primary winding of the transformer.

4. The power converting device of claim 2 , further comprising
a notification unit for performing notification,
wherein the controller makes the notification unit perform notification of a malfunction in accordance with an output from the malfunction detector.

5. The power converting device of claim 1 , wherein a plurality of the backflow preventing elements are each connected in parallel with the commutation rectifying element and the secondary winding of the transformer, and share the primary winding of the transformer.

6. The power converting device of claim 5 ,
wherein the secondary windings are reversely wound so that the commutation operations corresponding to the backflow preventing elements are performed at different timings.

7. The power converting device of claim 1 , wherein the transformer driving unit has a commutation power supply and a commutation switch and is connected to the primary winding of the transformer, and wherein the transformer driving unit controls the excitation current flowing from the commutation power supply toward the primary winding of the transformer by opening and closing the commutation switch.

8. The power converting device of claim 1 , wherein the commutating unit includes a protection device for interrupting an electric-current path that includes at least one of the primary winding and the secondary winding of the transformer, wherein the controller makes the protection device interrupt the electric-current path in accordance with an output from the malfunction detector.

9. The power converting device of claim 1 , wherein the controller adjusts a timing at which the commutating unit performs the commutation operation in accordance with an output from the malfunction detector.

10. The power converting device of claim 1 , wherein the controller adjusts a time period for which the commutating unit performs the commutation operation in accordance with an output from the malfunction detector.

11. The power converting device of claim 1 , further comprising a short-circuiting unit configured to short-circuit the power supply and control at least one of electric current and voltage,
wherein the controller stops an operation of the short-circuiting unit in accordance with an output from the malfunction detector.

12. The power converting device of claim 1 , further comprising:
a notification unit for performing notification,
wherein the controller makes the notification unit perform notification of a malfunction in accordance with an output from the malfunction detector.

13. The power converting device of claim 1 , wherein the commutating unit includes an electric-current suppressing element or an electric-current interrupting element in an electric-current path that includes at least one of the primary winding and the secondary winding of the transformer.

14. The power converting device of claim 1 , wherein a wide band-gap semiconductor is used as the commutation rectifying element.

15. The power converting device of claim 14 ,
wherein the wide band-gap semiconductor is composed of silicon carbide, gallium nitride, or diamond.

16. A motor driving device comprising:
an inverter unit that converts an output from the power converting device of claim 1 into alternating-current power;
an inverter controller that controls the inverter unit; and
a motor that is driven by the alternating-current power converted by the inverter unit.

17. The motor driving device of claim 16 ,
wherein when the malfunction detector of the power converting device detects a malfunction, the inverter controller limits driving of the motor.

18. A refrigerating and air-conditioning apparatus comprising the motor driving device of claim 17 for driving at least one of a compressor and an air-sending device.

19. The power converting device of claim 1 , further comprising:
a rectifying circuit that rectifies voltage of the power supply;
a smoothing unit that smoothes output voltage from the rectifying circuit;
a short-circuiting unit that is disposed more closely to the power supply than the smoothing unit and that short-circuits the power supply and controls at least one of electric current and voltage; and
a reactor that is disposed more closely to the power supply than the short-circuiting unit.

Assignees

• Shimomugi Takuya
• Arisawa Koichi
• Shinomoto Yosuke
• Yamakawa Takashi
• Mitsubishi Electric Corp

Inventors

• Shimomugi Takuya
• Arisawa Koichi
• Shinomoto Yosuke
• Yamakawa Takashi

Classifications

• H02M3/156

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H02P27/06

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

• H02P27/00

  Arrangements or methods for the control of AC motors characterised by the kind of supply voltage (of two or more motors H02P5/00; of synchronous motors with electronic commutators H02P6/00; of DC motors H02P7/00; of stepping motors H02P8/00) · CPC title

• H02M3/1584

  with a plurality of power processing stages connected in parallel · CPC title

• H02M2003/1586

  Electricity · mapped topic