Method for optically detecting an electrical arc in a power supply

• US 7,787,113 B2
• Filed: 05/18/2007
• Issued: 08/31/2010
• Est. Priority Date: 05/19/2006
• Status: Active Grant

• Current Assignee: Innomotics GmbH
• Original Assignee: Siemens Industry Incorporated (Siemens AG)
• Inventors: Aiello, Marc, Zhang, Xuan, Cheesman, Edward Alan
• Primary Examiner(s): PUNNOOSE, ROY M
• Application Number:
  US11/750,628
• Publication Number:
  US 20070268482A1
• Time in Patent Office: 1,201 Days
• Field of Search: 356/237.1
• US Class Current: 356/237.1
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0407 Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
• CPC Class Codes: G01R 31/1218 using optical methods; using charged particle, e.g. electron, beams or X-rays
• CPC Class Codes: G01R 31/62 Testing of transformers

Abstract

A method for optically detecting an electrical arc in a power supply. The method includes capturing light with a light pipe, transmitting the captured light along at least a portion of a length of the light pipe, optically detecting the transmitted light with a photodetector which is optically coupled to the light pipe, generating a signal indicative of an intensity of the detected light, and determining whether the detected light is associated with an electrical arc.

Claims

1. A method for optically detecting an electrical arc in a power supply having a plurality of cells, the method comprising:

capturing light at a first cell with at least one light pipe, wherein the light pipe is positioned such that a first portion of the light pipe is external to the first cell to capture light that may occur from an external electrical arc and a second portion of the light pipe is inside the cell to capture light that may occur from an internal electrical arc within the first cell;

transmitting the captured light along at least a portion of a length of the light pipe;

optically detecting the transmitted light with a photodetector which is optically coupled to the light pipe;

generating a signal indicative of an intensity of the detected light;

converting the generated signal to a digital signal; and

determining whether the detected light is associated with an electrical arc.

2. The method of claim 1, wherein capturing the light comprises capturing the light at an end of the light pipe.

3. The method of claim 1, wherein capturing the light comprises capturing the light along the length of the light pipe.

4. The method of claim 1, wherein transmitting the captured light along at least the portion of the length of the light pipe comprises transmitting the captured light to an end of the light pipe.

5. The method of claim 1, wherein generating the signal comprises generating a current indicative of an intensity of the detected light.

6. The method of claim 1, wherein determining whether the detected light is associated with the electrical arc comprises comparing a value of at least a portion of the generated signal with a threshold value.

7. The method of claim 1, further comprising filtering the generated signal.

8. The method of claim 1, further comprising determining whether the detected light is associated with a particular type of electrical arc.

9. The method of claim 8, wherein determining whether the detected light is associated with a particular type of electrical arc comprises analyzing an amplitude of at least a portion of the generated signal.

10. The method of claim 8, wherein determining whether the detected light is associated with a particular type of electrical arc comprises analyzing a frequency of at least a portion of the generated signal.

11. The method of claim 1, further comprising interrupting power to a the first cell when it is determined that the detected light is associated with the electrical arc.

12. The method of claim 11, further comprising electrically disconnecting an output of the first cell from a circuit which is connected to an output of at least one other power cell of the power supply.

13. The method of claim 1, further comprising interrupting power to each power cell of the power supply when it is determined that the detected light is associated with the electrical arc.

14. A method for optically detecting an electrical arc in a power supply having a plurality of cells, the method comprising:

capturing light at a first cell with at least one light pipe, wherein the light pipe is positioned such that a first portion of the light pipe is external to the first cell to capture light that may occur from an external electrical arc and a second portion of the light pipe is inside the cell to capture light that may occur from an internal electrical arc within the first cell;

transmitting the captured light along at least a portion of a length of the light pipe;

optically detecting the transmitted light with a photodetector which is optically coupled to the light pipe;

generating a signal indicative of an intensity of the detected light;

determining whether the detected light is associated with an electrical arc; and

determining whether the detected light is associated with a particular type of electrical arc.

15. The method of claim 14, wherein determining whether the detected light is associated with a particular type of electrical arc comprises analyzing an amplitude of at least a portion of the generated signal.

16. The method of claim 14, wherein determining whether the detected light is associated with a particular type of electrical arc comprises analyzing a frequency of at least a portion of the generated signal.

17. The method of claim 14, further comprising converting the generated signal to a digital signal.

18. A method for optically detecting an electrical arc in a power supply having a plurality of cells, the method comprising:

capturing light at a first cell with at least one light pipe, wherein the light pipe is positioned such that a first portion of the light pipe is external to the first cell to capture light that may occur from an external electrical arc and a second portion of the light pipe is inside the cell to capture light that may occur from an internal electrical arc within the first cell;

transmitting the captured light along at least a portion of a length of the light pipe;

optically detecting the transmitted light with a photodetector which is optically coupled to the light pipe;

generating a signal indicative of an intensity of the detected light;

determining whether the detected light is associated with an electrical arc; and

determining whether the detected light is associated with a particular type of electrical arc by analyzing either an amplitude or a frequency of at least a portion of the generated signal.