DEVICES, SYSTEMS, AND METHODS FOR ADAPTIVE RF SENSING IN ARC FAULT DETECTION

• US 20080024140A1
• Filed: 07/27/2006
• Published: 01/31/2008
• Est. Priority Date: 07/27/2006
• Status: Active Grant

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Siemens Energy & Automation Incorporated (Siemens AG)
• Inventors: Restrepo, Carlos, Henson, Jeremy
• Granted Patent: US 7,368,918 B2
• Time in Patent Office: Days
• US Class Current: 324/536
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02H 1/04 Arrangements for preventing response to transient abnormal conditions, e.g. to lightning or to short duration over voltage or oscillations; Damping the influence of dc component by short circuits in ac networks

Abstract

Certain exemplary embodiments comprise a method, which can comprise automatically generating an output signal responsive to an input signal. The input signal can be indicative of an arc fault. The output signal can be configured to cause an electrical circuit to open. The output signal can be generated responsive to a derived signal based upon a first threshold having a first amplitude.

Claims

1. A method comprising:

automatically generating an output signal responsive to an input signal, said input signal indicative of an arc fault, said output signal configured to cause an electrical circuit to open, said output signal generated responsive to a derived signal based upon a first threshold having a first amplitude, said first threshold changed from said first amplitude to a second amplitude if a predetermined percentage of historical sampled values of a measured electrical parameter are within a predetermined range during a predetermined time period, said second amplitude for said first threshold based upon an average of a predetermined count of said historical sampled values of said measured electrical parameter.

2. The method of claim 1, further comprising:

terminating a potential change of said first threshold responsive to a determination that an arc fault determination algorithm is operational.

3. The method of claim 1, further comprising:

obtaining said input signal.

4. The method of claim 1, further comprising:

mixing said input signal with an oscillating carrier.

5. The method of claim 1, further comprising:

mixing said input signal with an oscillating carrier; and

filtering said mixed signal.

6. The method of claim 1, further comprising:

mixing said input signal with an oscillating carrier;

filtering said mixed signal; and

amplifying said filtered signal.

7. The method of claim 1, further comprising:

mixing said input signal with an oscillating carrier;

filtering said mixed signal;

amplifying said filtered signal; and

measuring an energy magnitude of said amplified signal.

8. The method of claim 1, further comprising:

obtaining said derived signal.

9. The method of claim 1, further comprising:

changing said first threshold only when a predetermined variation measure associated with said predetermined count of historical sampled values is below a second threshold.

10. The method of claim 1, further comprising:

restarting an activity configured to change said first threshold after a predetermined time period.

11. The method of claim 1, further comprising:

storing each of said historical sampled values of said measured electrical parameter.

12. The method of claim 1, further comprising:

checking a sampled value of said measured electrical parameter to determine if said sampled value is within said predetermined range.

13. The method of claim 1, further comprising:

automatically changing a second threshold, having a third amplitude, said second threshold changed from said third amplitude to a fourth amplitude if said predetermined percentage of historical sampled values of said measured electrical parameter are within said predetermined range during said predetermined time period, said fourth amplitude for said second threshold based upon said average of said predetermined count of said historical sampled values of said measured electrical parameter.

14. The method of claim 1, wherein said second amplitude is determined by adding a predetermined voltage value to a sampled average of said predetermined count of historical sampled values of said measured electrical parameter.

15-19. -19. (canceled)