Look-ahead closed-loop thermal management

• US 6,198,245 B1
• Filed: 09/20/1999
• Issued: 03/06/2001
• Est. Priority Date: 09/20/1999
• Status: Expired due to Term

• Current Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Original Assignee: O2 Micro International Limited (O2 Micro Incorporated)
• Inventors: Yeh, Shih Ping, Kuo, Chuan Chiung, Shyr, You-Yuh, Du, Sterling
• Primary Examiner(s): Ip, Paul
• Application Number:
  US09/399,485
• Time in Patent Office: 533 Days
• Field of Search: 318/471-473, 361/195, 361/103, 361/20-34, 361/687, 361/688, 364/175, 364/695, 364/557, 364/483, 364/571.03, 236/446, 236/49.3, 702/132, 702/99, 702/130, 702/131, 374/134, 374/137, 713/300
• US Class Current: 318/471
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature
• CPC Class Codes: G05D 23/1917 using digital means

Abstract

Thermal management within an electrically powered systems requires monitoring, from time-to-time, both electrical power consumption and temperature within the system. The power consumption and temperature data thus obtained permits developing over time a thermal model for the system. After a thermal model for the system has been thus developed, the model together with the presently sensed electrical power consumption, and the system temperature are used to predict a thermal trend for the system. The predicted thermal trend thus obtained for the system is then used in effecting a temperature control strategy within the electrically powered system.

Claims

1. A method for thermal management within an electrically powered system comprising the steps of:

monitoring from time-to-time electrical power consumption within the system;

monitoring from time-to-time temperature within the system;

developing over time a thermal model for the system from the monitored electrical power consumption and system temperature;

using the thermal model, the presently sensed electrical power consumption, and the system temperature to predict a thermal trend for the system; and

applying the predicted thermal trend of the system for effecting a temperature control strategy within the electrically powered system.

2. The method of claim 1 wherein the step of monitoring electrical power consumption within the system includes directly monitoring electrical current supplied to the system.

3. The method of claim 1 wherein the step of monitoring electrical power consumption within the system includes directly monitoring an electrical signal within an electrical power converter that supplies electrically power to the system to thereby indirectly determine electrical current supplied to the system.

4. The method of claim 3 wherein the electrical signal is monitored within an alternating-current (“

AC”

) electrical power converter included in the system.

5. The method of claim 3 wherein the electrical signal is monitored within a direct-current to direct-current (“

DC-DC”

) electrical power converter included in the system.

6. The method of claim 5 further comprising the step of supplying electrically power to the DC-DC electrical power converter from a battery included in the system.

7. The method of claim 1 wherein the step of monitoring temperature within the system includes monitoring voltage present across a thermistor included in the system.

8. The method of claim 1 wherein the step of generating over time thermal model for the system includes storing thermal modeling data in a data storage device included in the system.

9. The method of claim 1 wherein the step of applying the predicted thermal trend of the system for effecting a temperature control strategy for the system includes turning-on a fan included in the system.

10. A thermal management controller adapted for use effecting a temperature control strategy within an electrically powered system for which a thermal trend may be predicted using a thermal model, the thermal management controller comprising:

a power consumption detection circuit for monitoring from time-to-time electrical power consumption within the system for use in predicting the thermal trend of the system using the thermal model;

an temperature sensing circuit for monitoring from time-to-time temperature of the system for use in predicting the thermal trend of the system using the thermal model; and

a temperature control circuit for effecting the temperature control strategy within the system.

11. The thermal management controller of claim 10 wherein said power consumption detection circuit directly monitors electrical current supplied to the system.

12. The thermal management controller of claim 10 wherein said power consumption detection circuit directly monitors an electrical signal within an electrical power converter that supplies electrically power to the system to thereby indirectly determine electrical current supplied to the system.

13. The thermal management controller of claim 12 wherein said electrical signal is monitored within an AC electrical power converter included in the system.

14. The thermal management controller of claim 12 wherein said electrical signal is monitored within a DC-DC electrical power converter included in the system.

15. The thermal management controller of claim 10 wherein said temperature sensing circuit monitors voltage present across a thermistor included in the system.

16. The thermal management controller of claim 10 wherein said temperature control circuit effects the temperature control strategy by turning-on a fan included in the system.