HEAT SINK COOLING ARRANGEMENT FOR MULTIPLE POWER ELECTRONIC CIRCUITS

• US 20120014063A1
• Filed: 07/16/2010
• Published: 01/19/2012
• Est. Priority Date: 07/16/2010
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Weiss, Bruce W.
• Granted Patent: US 8,335,081 B2
• Time in Patent Office: Days
• US Class Current: 361/697
• CPC Class Codes: H05K 13/00 Apparatus or processes specially adapted for manufacturing or adjusting assemblages of electric components
• CPC Class Codes: H05K 7/20163 the components being isolated from air flow, e.g. hollow heat sinks, wind tunnels or funnels
• CPC Class Codes: H05K 7/209 Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20909 takes precedence
• CPC Class Codes: H05K 7/20909 Forced ventilation, e.g. on heat dissipaters coupled to components
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

The present invention relates generally to tuning the flow of cooling air across converter and inverter heat sinks in a motor drive system. More specifically, present techniques relate to motor drive duct systems including heat sinks with separate, sequential heat sink fin sections disposed in a common cooling air path and having different geometries to optimize the flow of cooling air across and between fins of the separate heat sink fin sections. For example, the heat sink fin sections may have different fin lengths, fin heights, fin counts, fin pitch (e.g., distance between adjacent fins), and so forth. Each of these different geometric characteristics may be tuned to ensure that temperatures and temperature gradients across the heat sinks are maintained within acceptable ranges.

Claims

1. A power electronic system, comprising:

a cooling air duct configured to channel a flow of cooling air;

first, second, and third power electronic switching modules configured to perform controlled switching of respective first, second, and third phases of AC power, the power electronic switching modules being disposed adjacent to the cooling air duct;

first, second, and third heat sink sections disposed adjacent to the first, second, and third power electronic switching modules and extending into the cooling air duct in a sequential configuration wherein the second heat sink section receives cooling air from the first heat sink section, and the third heat sink section receives cooling air from the second heat sink section, each of the first, second, and third heat sink sections being physically configured differently from the other heat sink sections to reduce a working temperature of the respective power electronic switching module and to reduce working temperature differences between the power electronic switching modules; and

means for moving the cooling air through the cooling air duct and across the first, second, and third heat sink sections.

2. The system of claim 1, wherein the first, second, and third power electronic switching modules comprise a power inverter.

3. The system of claim 1, wherein the first, second, and third heat sink sections comprise fins that extend into the cooling air duct first, second, and third distances, respectively, the first distance being less than the second distance, and the second distance being less than the third distance.

4. The system of claim 1, wherein the first, second, and third heat sink sections comprise fins having first, second, and third lengths, respectively, the third length being greater than the first and second lengths.

5. The system of claim 1, wherein the first, second, and third heat sink sections comprise fins having first, second, and third pitches, respectively, the first pitch being greater than the second and third pitches.

6. The system of claim 1, wherein the first, second, and third heat sink sections are configured to provide substantially equal flow rates of heat from the respective power electronic switching module.

7. The system of claim 1, wherein the first, second, and third heat sink sections share a common base.

8. A power electronic system, comprising:

a cooling air duct configured to channel a flow of cooling air;

first, second, and third power electronic switching modules configured to perform controlled switching of respective first, second, and third phases of AC power, the power electronic switching modules being disposed adjacent to the cooling air duct;

first, second, and third heat sink sections disposed adjacent to the first, second, and third power electronic switching modules and extending into the cooling air duct in a sequential configuration wherein the second heat sink section receives cooling air from the first heat sink section, and the third heat sink section receives cooling air from the second heat sink section, each of the first, second, and third heat sink sections being physically configured differently from the other heat sink sections to reduce a working temperature of the respective power electronic switching module and to reduce working temperature differences between the power electronic switching modules; and

means for moving the cooling air through the cooling air duct and across the first, second, and third heat sink sections;

wherein the first heat sink section extends a first distance into the cooling air duct to permit a first cooling air stream to flow through the first heat sink section and a first bypass air stream to flow between the first heat sink section and a rear wall of the cooling air duct, the second heat sink section extends a second distance into the cooling air duct greater than the first distance to permit the first cooling air stream and a portion of the first bypass air stream to flow through the second heat sink section and a second bypass air stream to flow between the second heat sink section and the rear wall of the cooling air duct, and the third heat sink section extends a third distance into the cooling air duct greater than the second distance to permit cooling air from the second heat sink section and at least a portion of the second bypass air stream to flow through the third heat sink section.

9. The system of claim 8, wherein substantially all of the cooling air flows through the third heat sink section.

10. The system of claim 8, wherein the rear wall is substantially planar.

11. The system of claim 8, wherein the first, second, and third heat sink sections comprise fins having first, second, and third lengths, respectively, the third length being greater than the first and second lengths.

12. The system of claim 8, wherein the first, second, and third heat sink sections comprise fins having first, second, and third pitches, respectively, the first pitch being greater than the second and third pitches.

13. The system of claim 8, wherein the first, second, and third heat sink sections are configured to provide substantially equal flow rates of heat from the respective power electronic switching module.

14. The system of claim 8, wherein the first, second, and third heat sink sections share a common base.

15. A method for making a power electronic system, comprising:

disposing first, second, and third power electronic switching modules adjacent to a cooling air duct, the first, second, and third power electronic switching modules being configured to perform controlled switching of respective first, second, and third phases of AC power; and

disposing first, second, and third heat sink sections adjacent to the first, second, and third power electronic switching modules, the first, second, and third heat sink sections extending into the cooling air duct in a sequential configuration wherein the second heat sink section receives cooling air from the first heat sink section, and the third heat sink section receives cooling air from the second heat sink section, each of the first, second, and third heat sink sections being physically configured differently from the other heat sink sections to reduce a working temperature of the respective power electronic switching module and to reduce working temperature differences between the power electronic switching modules.

16. The method of claim 15, comprising disposing, adjacent to an end of the cooling air duct, means for moving the cooling air through the cooling air duct and across the first, second, and third heat sink sections.

17. The method of claim 15, wherein the first heat sink section extends a first distance into the cooling air duct to permit a first cooling air stream to flow through the first heat sink section and a first bypass air stream to flow between the first heat sink section and a rear wall of the cooling air duct, the second heat sink section extends a second distance into the cooling air duct greater than the first distance to permit the first cooling air stream and a portion of the first bypass air stream to flow through the second heat sink section and a second bypass air stream to flow between the second heat sink section and the rear wall of the cooling air duct, and the third heat sink section extends a third distance into the cooling air duct greater than the second distance to permit cooling air from the second heat sink section and at least a portion of the second bypass air stream to flow through the third heat sink section.

18. The method of claim 15, wherein the first, second, and third heat sink sections comprise fins having first, second, and third lengths, respectively, the third length being greater than the first and second lengths.

19. The method of claim 15, wherein the first, second, and third heat sink sections comprise fins having first, second, and third pitches, respectively, the first pitch being greater than the second and third pitches.

20. A power electronic system, comprising:

a cooling air duct;

a plurality of power electronic switching modules disposed adjacent to the cooling air duct;

a plurality of heat sink sections, each heat sink section being disposed adjacent to a respective power electronic switching module and extending into the cooling air duct in a sequential configuration in which each successive heat sink section receives at least a portion of its cooling air from a preceding heat sink section, wherein each of the heat sink sections is differently physically configured to reduce a working temperature of the respective power electronic switching module and to reduce working temperature differences between the power electronic switching modules; and

means for moving the cooling air through the cooling air duct and across the heat sink sections.