ARC FAULT CIRCUIT INTERRUPTER

• US 20150155698A1
• Filed: 06/17/2014
• Published: 06/04/2015
• Est. Priority Date: 12/02/2013
• Status: Active Grant

• Current Assignee: Chengli Li
• Original Assignee: Chengli Li
• Inventors: LI, Chengli, YUE, Guolan
• Granted Patent: US 9,640,968 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02H 3/044 Checking correct functioning of protective arrangements, e.g. by simulating a fault for differential current circuit breakers H02H3/335

Abstract

An arc fault detection circuit for an arc fault circuit interrupter (AFCI). The arc fault detection circuit includes an arc detecting circuit for detecting an arc fault in one or more power supply lines and outputting a detected signal, an arc filtering circuit electrically coupled to an output terminal of the arc detecting circuit for removing signal parts unrelated to the arc fault from the detected signal and outputting a filtered half-cycle signal, and an arc processing circuit electrically coupled to an output terminal of the arc filtering circuit for generating, based on the filtered half-cycle signal received, a processed half-cycle signal characterizing the arc fault. The arc fault detection circuit also includes simulated arc testing circuit that has a user-touchable test switch, and an arc oscillator to generate a simulated arc fault signal for testing the arc fault detection circuit or its respective components.

Claims

1. An arc fault detection circuit for an arc fault circuit interrupter (AFCI), comprising:

an arc detecting circuit for detecting an arc fault in one or more power supply lines and outputting a detected signal;

an arc filtering circuit electrically coupled to an output terminal of the arc detecting circuit for removing signal parts unrelated to the arc fault from the detected signal and outputting a filtered half-cycle signal; and

an arc processing circuit electrically coupled to an output terminal of the arc filtering circuit for generating, based on the filtered half-cycle signal received, a processed half-cycle signal characterizing the arc fault.

2. The arc fault detection circuit of claim 1, wherein the arc processing circuit comprises:

an half-cycle amplifying module for amplifying the filtered half-cycle signal; and

an arc triggering module electrically coupled to an output terminal of the half-cycle amplifying module for generating the processed half-cycle signal based on the filtered half-cycle signal.

3. The arc fault detection circuit of claim 2, wherein the half-cycle amplifying module comprises at least one linear amplifier.

4. The arc fault detection circuit of claim 2, wherein the arc triggering module comprises at least one oscillator.

5. The arc fault detection circuit of claim 2, wherein the arc triggering module comprises at least one logic gate circuit.

6. The arc fault detection circuit of claim 1, wherein the arc filtering circuit comprises:

a voltage regulating module electrically coupled to the arc detecting circuit for outputting a multi-amplitude half-cycle periodic voltage signal that corresponds to the detected signal; and

a phase-shifting module electrically coupled to an output terminal of the voltage regulating module for deriving the filtered half-cycle signal from the multi-amplitude half-cycle periodic voltage signal.

7. The arc fault detection circuit of claim 6, wherein the phase-shifting module is an at least bi-level resistor-capacitor (RC) circuit.

8. The arc fault detection circuit of claim 1, further comprises:

an arc fault triggering circuit comprising at least one solenoid and electrically coupled to the arc processing circuit for generating a switch control signal based on the processed half-cycle signal; and

a switch circuit electrically coupled to the arc fault triggering circuit to open the power supply lines in response to the switch control signal.

9. The arc fault detection circuit of claim 8, wherein the arc fault triggering circuit comprises at least one silicon controlled rectifier (SCR) having its gate terminal electrically coupled to an output terminal of the arc processing circuit.

10. The arc fault detection circuit of claim 8, further comprises a simulated arc testing circuit for generating a simulated arc signal to cause the switch circuit to open the power supply lines.

11. The arc fault detection circuit of claim 10, wherein the simulated arc testing circuit is electrically coupled to the at least one solenoid.

12. The arc fault detection circuit of claim 10, wherein the simulated arc testing circuit is electrically coupled directly to one of the power supply lines.

13. A simulated arc testing circuit for an arc fault detection circuit that is configured to detect an arc fault in one or more power supply lines and generate a processed half-cycle signal characterizing the arc fault, the simulated arc testing circuit comprising:

a user-touchable test switch; and

an arc oscillator electrically coupled to the test switch;

wherein the simulated arc testing circuit generates a simulated arc fault signal to cut-off the power supply lines.

14. The simulated arc testing circuit of claim 13 further determines whether to output the simulated arc fault signal based on a status of the test switch for testing the arc fault detection circuit or its respective components.

15. The simulated arc testing circuit of claim 13, wherein the arc oscillator utilizes a solenoid as an inductive component.

16. The simulated arc testing circuit of claim 13, wherein the test switch is electrically coupled to a solenoid of the arc fault detection circuit.

17. The simulated arc testing circuit of claim 14, wherein the test switch is electrically coupled directly to one of the power supply lines.

18. An arc fault detection circuit for an arc fault circuit interrupter (AFCI), comprising:

an arc detecting circuit for detecting an arc fault in one or more power supply lines and outputting a detected signal;

an arc filtering circuit electrically coupled to an output terminal of the arc detecting circuit for removing signal parts unrelated to the arc fault from the detected signal and outputting a filtered half-cycle signal;

an arc processing circuit electrically coupled to an output terminal of the arc filtering circuit for generating, based on the filtered half-cycle signal received, a processed half-cycle signal characterizing the arc fault; and

a simulated arc testing circuit electrically coupled directly to one of the power supply lines for generating a simulated arc signal to cut-off the power supply lines.

19. The arc fault detection circuit of claim 18, wherein the simulated arc testing circuit further comprising:

a user-touchable test switch; and

an arc oscillator electrically coupled to the test switch.

20. The arc fault detection circuit of claim 18, wherein the simulated arc testing circuit further determines whether to output the simulated arc fault signal based on a status of the test switch for testing the arc fault detection circuit or its respective components.