CONTROLLING CAPACITIVE SNUBBER AS FUNCTION OF CURRENT IN INVERTER

• US 20130293008A1
• Filed: 05/01/2012
• Published: 11/07/2013
• Est. Priority Date: 05/01/2012
• Status: Active Grant

• Current Assignee: Analogic Corporation
• Original Assignee: Analogic Corporation
• Inventors: Quigley, Stephen J.
• Granted Patent: US 9,431,921 B2
• Time in Patent Office: Days
• US Class Current: 307/11
• CPC Class Codes: H02M 1/34 Snubber circuits
• CPC Class Codes: H02M 1/342 Active non-dissipative snubbers
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

One or more systems and/or techniques are provided for electrically coupling and/or decoupling a capacitive snubber component to/from an inverter as a function of a current in the inverter. A current sensing component may be configured to measure the current in the inverter and/or determine whether the current in the inverter exceeds a desired threshold. The desired threshold may be set at a value sufficient to reset the capacitive snubber component. When the current in the inverter is above the desired threshold, the capacitive snubber component may be coupled to the inverter. When the current in the inverter is below the desired threshold, the capacitive snubber component may be decoupled from the inverter. In this way, little to no energy stored in the capacitive snubber component may be dissipated in the inverter when the current in the inverter drops below a level sufficient to reset the capacitive snubber component.

Claims

1. An inverter, comprising:

a capacitive snubber component; and

a switching component configured to electrically couple the snubber component to the inverter and to electrically decouple the snubber component from the inverter based upon a current of an electrical signal in the inverter.

2. The inverter of claim 1, comprising a current sensing component configured to determine whether the current of the electrical signal is greater than a desired threshold,

the switching component configured to electrically couple the snubber component to the inverter when the current of the electrical signal is greater than the desired threshold and to electrically uncouple the snubber component from the inverter when the current of the electrical signal is less than the desired threshold.

3. The inverter of claim 2, the current sensing component comprising a transformer.

4. The inverter of claim 2, the current sensing component comprising a hall effect sensor.

5. The inverter of claim 2, the current sensing component comprising a timing component configured to time at least one of the coupling of the snubber component to the inverter and the decoupling of the snubber component from the inverter.

6. The inverter of claim 5, the timing component comprising a flip-flop component.

7. The inverter of claim 1, the switching component comprising a switch configured to be open when the current of the electrical signal is less than a desired threshold, causing the snubber component to be electrically decoupled from the inverter, and configured to be closed when the current of the electrical signal is greater than the desired threshold, causing the snubber component to be electrically coupled to the inverter.

8. The inverter of claim 1, the desired threshold a function of a value of the electrical current that resets the snubber component.

9. The inverter of claim 1, the snubber component configured to extend a transitional period of the electrical signal from a first voltage to a second voltage such that an amount of power dissipated during the transitional period is reduced.

10. The inverter of claim 1, the inverter comprising a series resonant inverter.

11. The inverter of claim 10, the series resonant inverter configured for a peak output power of between about 10 kW and about 90 kW and an average output power of between about 2 kW and about 10 kW.

12. The inverter of claim 1, the inverter configured to output power, at least some of the output power supplied to a radiation source of a radiology modality that is electrically coupled to the inverter.

13. The inverter of claim 1, comprising a second capacitive snubber component and the switching component configured to electrically couple the second snubber component to the inverter and to electrically decouple the second snubber component from the inverter based upon the current of the electrical signal in the inverter.

14. The inverter of claim 1, the snubber component coupled in series with the switching component.

15. A method for selectively coupling a capacitive snubber component to an inverter, comprising:

measuring a current of an electrical signal in the inverter,

electrically coupling the capacitive snubber component to the inverter when the current of the electrical signal is greater than a desired threshold; and

electrically decoupling the capacitive snubber component from the inverter when the current of the electrical signal is below the desired threshold.

16. The method of claim 15, the desired threshold a function of a value of an electrical current that resets the snubber component.

17. The method of claim 15, the inverter comprising a series resonant inverter.

18. The method of claim 15, the inverter configured to output a peak power that is at least five times an average power output by the inverter.

19. The method of claim 18, the inverter configured to output a peak power of at least 40 kW.

20. A radiology imaging modality, comprising:

an ionizing radiation source configured to emit radiation, energy of the radiation a function of at least one of a voltage and a power supplied to the radiation source;

a detector array configured to detect at least some of the emitted radiation that traversed an object under examination;

an image generation component configured to generate an image of the object based at least in part upon the detected radiation; and

a power supply configured to provide power to the ionizing radiation source, the power supply comprising an inverter, the inverter comprising;

a capacitive snubber component, and

a switching component configured to electrically couple the snubber component to the inverter and to electrically decouple the snubber component from the inverter based upon a current of an electrical signal in the inverter.