Power converters with operating efficiency monitoring for fault detection

• US 7,719,808 B2
• Filed: 05/15/2007
• Issued: 05/18/2010
• Est. Priority Date: 05/15/2007
• Status: Active Grant

• Current Assignee: Astec International Limited (Emerson Electric Company)
• Original Assignee: Astec International Limited (Emerson Electric Company)
• Inventors: Asuncion, Arlaindo, Currie, Gordon, Phadke, Vijay
• Primary Examiner(s): Leja; Ronald W
• Application Number:
  US11/803,706
• Publication Number:
  US 20080285184A1
• Time in Patent Office: 1,099 Days
• Field of Search: 361/79
• US Class Current: 361/79
• CPC Class Codes: H02H 3/44 responsive to the rate of change of electrical quantities
• CPC Class Codes: H02H 5/04 responsive to abnormal temperature specially adapted for electric machines H02H7/0852
• CPC Class Codes: H02H 7/1203 Circuits independent of the type of conversion

Abstract

A power converter includes a controller and at least one output terminal for providing an output voltage and an output current to a load. The controller is configured for monitoring the output voltage and the output current and calculating an efficiency of the power converter based on the monitored output voltage and output current. The controller is also configured to generate a fault signal after detecting a degradation in the power converter efficiency.

Claims

1. A power converter comprising a controller and at least one output terminal for providing an output voltage and an output current to a load, the controller configured for monitoring the output voltage and the output current and calculating an efficiency of the power converter based on the monitored output voltage and output current, the controller configured for generating a fault signal after detecting a degradation in the power converter efficiency.

2. The power converter of claim 1 wherein the controller is configured for comparing the calculated efficiency with stored data to detect the degradation.

3. The power converter of claim 2 wherein the controller is configured for generating the fault signal when the degradation exceeds a threshold level.

4. The power converter of claim 2 wherein the stored data includes a plurality of values each corresponding to a particular operating condition of the power converter.

5. The power converter of claim 4 further comprising a look-up table storing the plurality of values.

6. The power converter of claim 5 further comprising at least one input terminal for receiving an input voltage and an input current, wherein the controller is configured to monitor the input voltage and the input current, and to calculate an efficiency of the power converter based on the monitored input voltage, input current, output voltage and output current.

7. The power converter of claim 6 wherein the controller is configured for providing the fault signal to a system hosting the power converter.

9. The power converter of claim 1 wherein the controller is configured for providing the fault signal to a system hosting the power converter.

11. The power converter of claim 1 wherein the controller is configured for shutting down the power converter after generating the fault signal.

8. The power converter of 7 wherein the controller is configured for shutting down the power converter in response to a command from the system hosting the power converter.

10. The power converter of 9 wherein the controller is configured for shutting down the power converter in response to a command from the system hosting the power converter.

12. A method of predicting faults in a power converter, the method comprising:

monitoring an output voltage and an output current of the power converter;

calculating an efficiency of the power converter based on the monitored output voltage and output current; and

generating a fault signal after detecting a degradation in the power converter efficiency.

13. The method of claim 12 further comprising repairing or replacing the power converter in response to the fault signal.

14. The method of claim 12 wherein generating includes generating the fault signal when the degradation exceeds a threshold level.

15. The method of claim 14 wherein monitoring includes monitoring an input voltage and an input current of the power converter, and wherein calculating includes calculating an efficiency of the power converter based on the monitored input voltage, input current, output voltage and output current.

16. The method of claim 15 further comprising comparing the calculated efficiency with stored data.

17. The method of claim 16 wherein the stored data includes a plurality of values each corresponding to a particular operating condition of the power converter.

18. The method of claim 17 wherein the plurality of values are stored in a look-up table.