Power converter temperature estimation

• US 10,256,024 B1
• Filed: 01/15/2018
• Issued: 04/09/2019
• Est. Priority Date: 01/15/2018
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Rogers, Craig Brian
• Primary Examiner(s): Dole, Timothy J.
• Assistant Examiner(s): Tiku, Sisay G
• Application Number:
  US15/871,668
• Time in Patent Office: 449 Days
• CPC Class Codes: G01R 19/10 Measuring sum, difference or ratio
• CPC Class Codes: G01R 19/12 Measuring rate of change
• CPC Class Codes: H01F 27/008 with temperature compensation
• CPC Class Codes: H02J 1/04 Constant-current supply systems
• CPC Class Codes: H02J 7/24 using discharge tubes or semiconductor devices
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 1/327 against abnormal temperatures
• CPC Class Codes: H02M 3/145 using devices of a triode or transistor type requiring continuous application of a control signal
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A vehicle includes a power converter having an inductor electrically disposed between a traction battery and an electric machine. The vehicle includes a controller configured to reduce a power limit of the power converter. The reduction is responsive to an increase of a ratio of voltage across the inductor to a rate of change of current through the inductor.

Claims

1. A vehicle comprising:

a power converter including an inductor electrically disposed between a traction battery and an electric machine; and

a controller configured to, responsive to an increase of a ratio of voltage across the inductor to a rate of change of current through the inductor, reduce a maximum allowable ON period for switches of the power converter to reduce a power limit of the power converter.

2. The vehicle of claim 1, wherein the controller is further configured to, responsive to a decrease of the ratio, increase the power limit of the power converter.

3. The vehicle of claim 1, wherein the inductor includes a core having an initial permeability that is a monotonic function of temperature of the core.

4. The vehicle of claim 1, wherein the inductor includes a powdered iron core.

5. The vehicle of claim 4, wherein the powdered iron core is a Molypermalloy Powder core.

6. The vehicle of claim 5, wherein the Molypermalloy Powder core has an initial permeability of 550μ

.

7. A vehicle comprising:

a power converter including an inductor electrically disposed between a traction battery and an electric machine; and

a controller configured to, responsive to a decrease of a ratio of voltage across the inductor to a rate of change of current through the inductor, increase a maximum allowable ON period for switches of the power converter to increase a power limit of the power converter.

8. The vehicle of claim 7, wherein the controller is further configured to, responsive to an increase of the ratio, reduce the power limit of the power converter.

9. The vehicle of claim 7, wherein the inductor includes a core having an initial permeability that is a monotonic function of temperature of the core.

10. The vehicle of claim 7, wherein the inductor includes a powdered iron core.

11. The vehicle of claim 10, wherein the powdered iron core is a Molypermalloy Powder core.

12. The vehicle of claim 11, wherein the Molypermalloy Powder core has an initial permeability of 550μ

.

13. A method comprising:

by a controller,

responsive to a change of a ratio of voltage across an inductor to a rate of change of current through the inductor, adjusting a maximum allowable ON period for switches of a power converter to adjust a power limit of the power converter including the inductor electrically disposed between a traction battery and an electric machine.

14. The method of claim 13, wherein the adjusting is an increase in the power limit when the change is a decrease.

15. The method of claim 13, wherein the adjusting is a decrease in the power limit when the change is an increase.

16. The method of claim 13, wherein the inductor includes a core having an initial permeability that is a monotonic function of temperature of the core.

17. The method of claim 13, wherein the inductor includes a powdered iron core.

18. The method of claim 17, wherein the powdered iron core is a Molypermalloy Powder core.

19. The method of claim 18, wherein the Molypermalloy Powder core has an initial permeability of 550μ

.