Series arc fault current interrupters and methods

• US 20090059449A1
• Filed: 10/29/2008
• Published: 03/05/2009
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: General Electric Company
• Inventors: Younsi, Karim, Yan, Weizhong, Zhou, Yingneng, Hu, Xiao, Dwyer, Sean, Prasad, Vijaysai, Vijayan, Pradeep, Rivers, Cecil
• Granted Patent: US 7,826,184 B2
• Time in Patent Office: Days
• US Class Current: 361/42
• CPC Class Codes: H02H 1/0015 Using arc detectors

Abstract

A circuit interrupter for interrupting current on a line conductor is provided. The circuit interrupter includes separable contacts, a trip mechanism, a bimetal, a microprocessor, a series arc detection sequence, a low-pass filter circuit, and a high-pass filter circuit. The trip mechanism selectively opens the separable contacts when activated. The series arc detection sequence is resident on the microprocessor and includes a plurality of series fault detection algorithms. The low-pass filter circuit provides a low-pass signal to the series arc detection sequence. The high-pass filter circuit provides a high-pass signal to the series arc detection sequence. The sequence selects a particular algorithm from the plurality of algorithms based on the low-pass signal. The sequence calculates a plurality of statistical features from the high-pass signal and sends an output signal to activate the trip mechanism based on a comparison of the plurality of statistical features to the particular algorithm.

Claims

1. A circuit interrupter for interrupting current on a line conductor, comprising:

separable contacts in electrical communication with the line conductor;

a trip mechanism for selectively opening said separable contacts upon receipt of a trip signal;

a sensor in electrical communication with the line conductor;

a processing device in electrical communication with said trip mechanism;

a series arc detection sequence resident on said processing device, said series arc detection sequence comprising a plurality of series fault detection algorithms; and

at least one filter circuit providing at least one signal from said sensor to said series arc detection sequence, said sequence selecting a particular algorithm from said plurality of algorithms based on said at least one signal, calculating a plurality of statistical features from said at least one signal, and generating said trip signal based on a comparison of said plurality of statistical features to said particular algorithm.

2. The circuit interrupter as in claim 1, wherein said sensor comprises a bimetal connected in series with the line conductor.

3. The circuit interrupter as in claim 1, further comprising a parallel arc detector in electrical communication with the line conductor, said parallel arc detector generating said trip signal upon detection of a parallel arc across the line conductor.

4. The circuit interrupter as in claim 1, wherein said trip mechanism opens said separable contacts upon application of an overcurrent across said sensor and/or upon application of a short circuit across said sensor.

5. The circuit interrupter as in claim 4, further comprising a parallel arc detector in electrical communication with the line conductor, said parallel arc detector generating said trip signal upon detection of a parallel arc across the line conductor.

6. The circuit interrupter as in claim 1, wherein said at least one filter circuit comprises a low-pass filter circuit.

7. The circuit interrupter as in claim 6, wherein said low-pass filter circuit is configured to provide a low-pass signal from said sensor to said series arc detection sequence, said sequence selecting said particular algorithm from said plurality of algorithms based on said low-pass signal.

8. The circuit interrupter as in claim 7, further comprising an analog-to-digital converter for sampling said low-pass signal from said low-pass filter circuit.

9. The circuit interrupter as in claim 6, wherein said low-pass filter circuit further comprises a DC offset.

10. The circuit interrupter as in claim 1, wherein said at least one filter circuit comprises high-pass filter circuit.

11. The circuit interrupter as in claim 10, wherein said high-pass filter circuit provides a high-pass signal from said sensor to said series arc detection sequence, said sequence calculating said plurality of statistical features from said high-pass signal.

12. The circuit interrupter as in claim 11, further comprising an analog-to-digital converter for sampling said high-pass signal from said high-pass filter circuit.

13. The circuit interrupter as in claim 10, wherein said high-pass filter circuit further comprises an amplifier and a DC offset.

14. A circuit interrupter for interrupting current on a line conductor, comprising:

separable contacts in electrical communication with the line conductor;

a trip mechanism for selectively opening said separable contacts upon receipt of a trip signal;

a sensor in electrical communication with the line conductor;

a processing device in electrical communication with said trip mechanism;

a series arc detection sequence resident on said processing device, said series arc detection sequence comprising a plurality of series fault detection algorithms;

a low-pass filter circuit in electrical communication with said sensor, said low-pass filter circuit passing a low-pass signal from said sensor to said series arc detection sequence, said sequence selecting a particular algorithm from said plurality of algorithms based on said low-pass signal; and

a high-pass filter circuit in electrical communication with said sensor, said high-pass filter circuit passing a high-pass signal from said sensor to said series arc detection sequence, said sequence calculating a plurality of statistical features from said high-pass signal and generating said trip signal based on a comparison of said plurality of statistical features to said particular algorithm.

15. The circuit interrupter as in claim 14, further comprising a parallel arc detector in electrical communication with the line conductor, said parallel arc detector generating said trip signal upon detection of a parallel arc across the line conductor.

16. The circuit interrupter as in claim 14, wherein said sensor comprises a bimetal connected in series with the line conductor.

17. The circuit interrupter as in claim 15, wherein said trip mechanism opens said separable contacts upon application of an overcurrent across said bimetal and/or upon application of a short circuit across said bimetal.

18. The circuit interrupter as in claim 17, further comprising a parallel arc detector in electrical communication with the line conductor, said parallel arc detector generating said trip signal upon detection of a parallel arc across the line conductor.