Temperature estimation based on a signal oscillation

• US 7,522,434 B2
• Filed: 10/27/2005
• Issued: 04/21/2009
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Original Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Inventors: Nahar, Anusheel, Lorenz, Robert Donald
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US11/260,885
• Publication Number:
  US 20070097718A1
• Time in Patent Office: 1,272 Days
• Field of Search: 323/265, 323/273, 323/282, 363/65
• US Class Current: 363/65
• CPC Class Codes: G01K 7/425 Thermal management of integrated systems
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection

Abstract

A method of estimating a temperature at a component of a device is provided. The temperature may be used to provide thermal load management of the device. In an exemplary embodiment, a switched mode power converter includes a power converter module and a switch that controls a switching cycle of the power converter module. A signal includes a bus voltage component and an oscillating signal component at least partially caused by switching of the switch. A switch instant of the switch can be isolated. A characteristic of the oscillating signal component of the signal can be detected. For example, a first peak voltage of the oscillating signal component can be detected after the switch instant. The temperature of the power converter module is estimated using the detected characteristic of the oscillating signal component. For example, the temperature can be estimated using the first peak voltage and best-fit curve parameters in solving a linear or a quadratic equation.

Claims

1. A power converter module of a switched mode power converter, the power converter module comprising:

an interface circuit, the interface circuit comprising

a timing circuit configured to isolate a switch instant of a switch of a switched mode power converter, wherein switching of the switch at least partially causes an oscillating signal component within a signal after each switch instant; and

a detector circuit configured to detect a first peak voltage and a second peak voltage of the oscillating signal component after the isolated switch instant;

a computer-readable medium having computer-readable instructions stored thereon, the instructions configured to cause the power converter module to

receive a first value for the detected first peak voltage and a second value for the detected second peak voltage; and

estimate a temperature of the power converter module using the received first value and the received second value by solving a quadratic equation for the temperature having the form (B₁A₂−

B₂A₁)T²+(E₁A₂−

A₁E₂+B₁C₂−

C₁B₂−

v₁A₂+v₂A₁)T+E₁C₂−

C₁E₂+v₂C₁−

v₁C₂=0;

where T is the temperature, v₁ is the first value, v₂ is the second value, and A₁, A₂, B₁, B₂, C₁, C₂, E₁, and E₂ are best-fit parameters; and

a processor, the processor coupled to the computer-readable medium to execute the instructions.

2. The power converter module of claim 1 wherein the instructions are further configured to cause the power converter module to remove a bus voltage component of the signal.

3. The power converter module of claim 1 wherein the switch instant is a turn-on switch instant of the switch.

4. The power converter module of claim 3 wherein the instructions are further configured to cause the power converter module to remove a portion of the oscillating signal component caused by a turn-off switch instant of the switch.

5. The power converter module of claim 1 wherein the switch instant is a turn-off switch instant of the switch.

6. A power converter module of a switched mode power converter, the power converter module comprising:

an interface circuit, the interface circuit comprising

a timing circuit configured to isolate a switch instant of a switch of a switched mode power converter, wherein switching of the switch at least partially causes an oscillating signal component within a signal after each switch instant; and

a detector circuit configured to detect a first peak voltage and an off-state voltage of the oscillating signal component after the isolated switch instant;

a computer-readable medium having computer-readable instructions stored thereon, the instructions configured to cause the power converter module to

receive a first value for the detected first peak voltage and a second value for the detected off-state voltage; and

estimate a temperature of the power converter module using the received first value and the received second value by solving a linear equation for the temperature having the form v₁=(F₁V_o+B₁)T+G₁V_o+E₁;

where T is the temperature, v₁ is the first value, V_o is the second value, and B₁, E₁, F₁, and G₁ are best-fit parameters.

7. The power converter module of claim 6 wherein the instructions are further configured to cause the power converter module to remove a bus voltage component of the signal.

8. The power converter module of claim 6 wherein the switch instant is a turn-on switch instant of the switch.

9. The power converter module of claim 8 wherein the instructions are further configured to cause the power converter module to remove a portion of the oscillating signal component caused by a turn-off switch instant of the switch.

10. A power converter module of a switched mode power converter, the power converter module comprising:

a timing means for isolating a switch instant of a switch of a switched mode power converter, wherein switching of the switch at least partially causes an oscillating signal component within a signal after each switch instant;

a detecting means for detecting a first peak voltage and a second peak voltage of the oscillating signal component after the isolated switch instant; and

a processing means for executing computer-readable instructions, the instructions configured to cause the power converter module to

receive a first value for the detected first peak voltage and a second value for the detected second peak voltage; and

estimate a temperature of the power converter module using the received first value and the received second value by solving a quadratic equation for the temperature having the form ( B₁A₂−

B₂A₁)T²+(E₁A₂−

A₁E₂+B₁C₂−

C₁B₂−

v₁A₂+v₂A₁)T+E₁C₂−

C₁E₂+v₂C₁−

v₁C₂=0;

where T is the temperature, v₁ is the first value, v₂ is the second value, and A₁, A₂, B₁, B₂, C₁,C₂, E₁, and E₂ are best-fit parameters.

11. A method of estimating a temperature at a component of a device, wherein the temperature may be used to provide thermal load management of the device, the method comprising:

isolating a switch instant of a switch wherein switching of the switch at least partially causes an oscillating signal component within a signal after each switch instant;

detecting a first peak voltage and a second peak voltage of the oscillating signal component; and

estimating a temperature of a component of a device using the detected first peak voltage and the detected second peak voltage by solving a quadratic equation for the temperature having the form (B₁A₂−

B₂A₁)T²+(E₁A₂−

A₁E₂+B₁C₂−

C₁B₂−

v₁A₂+v₂A₁)T+E₁C₂−

C₁E₂+v₂C₁−

v₁C₂=0;

where T is the temperature, v₁ is the first peak voltage, v₂ is the second peak voltage, and A₁, A₂, B₁, B₂, C₁C₂, E₁, and E₂ are best-fit parameters.

12. The method of claim 11 wherein the switch is a semiconductor switch.

13. The method of claim 11 wherein the component is a semiconductor switch.

14. The method of claim 11 wherein the component is a power converter module.

15. The method of claim 11 wherein the device is a power converter, the power converter comprising a plurality of power converter modules that supply a load based on a known switching cycle, the known switching cycle using an interleaved commutation sequence.

16. The method of claim 15, wherein the switch is associated with any of the plurality of power converter modules.

17. The method of claim 11 wherein the signal is selected from the group consisting of an input bus voltage signal, an output bus voltage signal, an input bus current signal, and an output bus current signal.

18. The method of claim 17 further comprising removing a bus voltage component of the signal.

19. The method of claim 18 wherein removing the bus voltage component of the signal uses a high pass filter.

20. The method of claim 11 wherein the switch instant is a turn-on switch instant of the switch.

21. The method of claim 20 further comprising removing a portion of the oscillating signal component caused by a turn-off switch instant of the switch.

22. The method of claim 21 wherein removing the portion of the oscillating signal is performed using an analog multiplexer.

23. The method of claim 11 wherein the switch instant is a turn-off switch instant of the switch.

24. The method of claim 11 wherein the second peak voltage of the oscillating signal component is detected after detecting the first peak voltage.

25. The method of claim 11 wherein the first peak voltage is selected from the group consisting of a positive peak voltage and a negative peak voltage.

26. The method of claim 11 wherein the second peak voltage is selected from the group consisting of a positive peak voltage and a negative peak voltage.

27. The method of claim 11 wherein isolating the switch instant is performed based on a known switching cycle.

28. The method of claim 11 wherein isolating the switch instant is performed using a transistor based switching circuit.

29. The method of claim 11 further comprising performing thermal load management of the device using the estimated temperature.

30. A method of estimating a temperature at a component of a device, wherein the temperature may be used to provide thermal load management of the device, the method comprising:

calculating best-fit parameters for best-fit curves, wherein the best-fit parameters are calculated by

(a) defining an operating range of a fitting parameter;

(b) selecting an operating value from the operating range, wherein a switching cycle is based on the selected operating value;

(c) switching a switch based on the selected operating value;

(d) measuring a first temperature of a device;

(e) isolating a first switch instant of the switch wherein switching of the switch at least partially causes a first oscillating signal component within a signal after the first switch instant;

(f) detecting a first peak voltage value of the first oscillating signal component after the isolated first switch instant;

(g) detecting a second peak voltage value of the first oscillating signal component after detecting the first peak voltage value;

(h) saving the measured first temperature, the detected first peak voltage value, and the detected second peak voltage value;

(i) repeating (d)-(h) for a range of temperatures between an initial temperature and a final temperature;

(j) for the final temperature, calculating a first slope and a first intercept of a first curve fitting the detected first peak voltage value and the measured first temperature;

(k) for the final temperature, calculating a second slope and a second intercept of a second curve fitting the detected second peak voltage value and the measured first temperature;

(l) saving the selected operating value, the calculated first slope, the calculated first intercept, the calculated second slope, and the calculated second intercept;

(m) repeating (b)-(l) for the defined operating range;

(n) after processing the defined operating range, calculating a third slope and a third intercept of a third curve fitting the calculated first slope and the selected operating value, wherein A₁ is the third slope and B₁ is the third intercept;

(o) after processing the defined operating range, calculating a fourth slope and a fourth intercept of a fourth curve fitting the calculated first intercept and the selected operating value, wherein C₁ is the fourth slope and E₁ is the fourth intercept;

(p) after processing the defined operating range, calculating a fifth slope and a fifth intercept of a fifth curve fitting the calculated second slope and the selected operating value, wherein A₂ is the fifth slope and B₂ is the fifth intercept; and

(q) after processing the defined operating range, calculating a sixth slope and a sixth intercept of a sixth curve fitting the calculated second intercept and the selected operating value, wherein C₂ is the sixth slope and E₂ is the sixth intercept;

isolating a second switch instant of the switch wherein switching of the switch at least partially causes a second oscillating signal component within the signal after the second switch instant;

detecting a third peak voltage and a fourth peak voltage of the second oscillating signal component; and

estimating a temperature of a component of the device using the calculated best-fit parameters, the detected third peak voltage, and the detected fourth peak voltage.

31. The method of claim 30 wherein the operating value is a duty ratio value.

32. The method of claim 30 wherein the operating value is an off-state voltage value.

33. A method of estimating a temperature at a component of a device, wherein the temperature may be used to provide thermal load management of the device, the method comprising;

isolating a switch instant of a switch wherein switching of the switch at least partially causes an oscillating signal component within a signal after each switch instant;

detecting a first peak voltage and an off-state voltage of the oscillating signal component; and

estimating a temperature of a component of a device using the detected first peak voltage and the detected off-state voltage and solving a linear equation for the temperature, the linear equation having the form v₁=(F₁V_o+B₁)T+G₁V_o+E₁;

where T is the temperature, v₁ is the first peak voltage, V_o is the off-state voltage, and B₁, E₁, F₁, and G₁ are best-fit parameters.

34. The method of claim 33 further comprising removing a bus voltage component of the signal.

35. The method of claim 33 wherein the switch instant is a turn-on switch instant of the switch.

36. The method of claim 35 further comprising removing a portion of the oscillating signal component caused by a turn-off switch instant of the switch.

37. The method of claim 33 wherein the switch instant is a turn-off switch instant of the switch.