Temperature estimation based on a signal oscillation

• US 20070097718A1
• Filed: 10/27/2005
• Published: 05/03/2007
• 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: Lorenz, Robert, Nahar, Anusheel
• Granted Patent: US 7,522,434 B2
• Time in Patent Office: Days
• 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 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 to detect a characteristic of the oscillating signal component after the isolated switch instant;

a computer-readable medium having computer-readable instructions stored thereon, the instructions comprising

receiving the detected characteristic; and

estimating a temperature of the power converter module using the received characteristic; 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 to estimate the temperature include best-fit parameters, wherein the best-fit parameters define best-fit curves.

3. The power converter module of claim 2, wherein the instructions to estimate the temperature include instructions to solve a quadratic equation for the temperature.

4. The power converter module of claim 3, wherein the quadratic equation has the form (B₁A₂−

B₂A₁)T²+(E₁A₂−

A₁E₂+B₁C₂−

C₁B₂−

v₁A₂+v₂A₁)T+E₁C₂−

C₁E₂+v₂C₁−

v₁C₂=0;

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

5. The power converter module of claim 2, wherein the instructions to estimate the temperature include instructions to solve a linear equation for the temperature.

6. The power converter module of claim 5, wherein the linear equation has the form v₁=(F₁V_o+B₁)T+G₁ V_o+E₁;

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

7. 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 characteristic of the oscillating signal component after the isolated switch instant; and

a processing means for executing computer-readable instructions, the instructions comprising

receiving the detected characteristic; and

estimating a temperature of the power converter module using the received characteristic.

8. 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 characteristic of the oscillating signal component; and

estimating a temperature of a component of a device using the detected characteristic.

9. The method of claim 8 wherein the switch is a semiconductor switch.

10. The method of claim 8 wherein the component is a semiconductor switch.

11. The method of claim 8 wherein the component is a power converter module.

12. The method of claim 8 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.

13. The method of claim 12, wherein the switch is associated with any of the plurality of power converter modules.

14. The method of claim 8 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.

15. The method of claim 14 further comprising removing a bus voltage component of the signal.

16. The method of claim 15 wherein removing the bus voltage component of the signal uses a high pass filter.

17. The method of claim 8 wherein the switch instant is a turn-on switch instant of the switch.

18. The method of claim 17 further comprising removing a portion of the oscillating signal component caused by a turn-off switch instant of the switch.

19. The method of claim 18 wherein removing the portion of the oscillating signal is performed using an analog multiplexer.

20. The method of claim 8 wherein the switch instant is a turn-off switch instant of the switch.

21. The method of claim 8 wherein the detected characteristic includes a first peak voltage value of the oscillating signal component detected after the isolated switch instant.

22. The method of claim 21 wherein the detected characteristic includes a second peak voltage value of the oscillating signal component detected after detecting the first peak voltage value.

23. The method of claim 21 wherein the first peak voltage value is selected from the group consisting of a positive peak voltage value and a negative peak voltage value.

24. The method of claim 22 wherein the second peak voltage value is selected from the group consisting of a positive peak voltage value and a negative peak voltage value.

25. The method of claim 8 wherein estimating the temperature includes solving a quadratic equation for the temperature.

26. The method of claim 22 further comprising calculating best-fit parameters, wherein the best-fit parameters define best-fit curves.

27. The method of claim 26, wherein estimating the temperature includes solving a quadratic equation for the temperature, the quadratic equation 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 value, v₂ is the second peak voltage value, and A₁, A₂, B₁, B₂, C₁, C₂, E₁, and E₂ are the best-fit parameters.

28. The method of claim 26, wherein calculating the best-fit parameters comprises:

(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 the switch based on the selected operating value;

(d) measuring a first temperature of the device;

(e) isolating a first switch instant of the switch;

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

(g) detecting a fourth peak voltage value of the oscillating signal component after detecting the third peak voltage value;

(h) saving the measured first temperature, the detected third peak voltage value, and the detected fourth 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 third 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 fourth 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.

29. The method of claim 28 wherein the operating value is a duty ratio value.

30. The method of claim 28 wherein the operating value is an off-state voltage value.

31. The method of claim 8 wherein estimating the temperature includes solving a linear equation for the temperature.

32. The method of claim 21 further comprising calculating best-fit parameters, wherein the best-fit parameters define best-fit curves.

33. The method of claim 32, wherein estimating the temperature includes 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 value, V_o is an off-state voltage value, and B₁, E₁, F₁, and G₁ are the best-fit parameters.

34. The method of claim 8 wherein isolating the switch instant is performed based on a known switching cycle.

35. The method of claim 8 wherein isolating the switch instant is performed using a transistor based switching circuit.

36. The method of claim 8 further comprising performing thermal load management of the device using the estimated temperature.

37. A computer-readable medium having computer-readable instructions stored thereon that, upon execution by a processor, cause the processor to estimate a temperature at a component of a device, wherein the temperature may be used to provide thermal load management of the device, the instructions comprising:

receiving a characteristic detected from an oscillating signal component of a signal detected after a switch instant, wherein a switch is switched at the switch instant, and further wherein the switching of the switch at least partially causes the oscillating signal component; and

estimating a temperature of a component of a device using the detected characteristic.