CN-122003612-A - System and method for detecting and identifying arcing based on discrete-time signal processing

Abstract

A circuit interrupting device includes a line terminal, a current sensor that measures current flowing through the line terminal, a zero crossing detection circuit that measures voltage and frequency of the line terminal, and a microcontroller. The microcontroller is configured to apply a digital filter to the line current measurement signal, determine a zero crossing position of the line voltage measurement signal, count a plurality of turning points of the filtered line current measurement signal, determine a position of each of the plurality of turning points relative to a corresponding zero crossing position, determine a time between each turning point and a subsequent turning point, and determine whether an arc fault exists within the circuit interrupting device based on the plurality of turning points, the position of each turning point relative to the corresponding zero crossing position, and the time between each turning point and the subsequent turning point.

Inventors

• Brian Kia
• James Casey Mussen
• Ricky He

Assignees

• 豪倍公司

Dates

Publication Date

20260508

Application Date

20241009

Priority Date

20231011

Claims (20)

1. 1. A circuit interrupting device, comprising: A line terminal; a current sensor configured to measure a current flowing through the line terminal; a zero crossing detection circuit configured to measure a voltage and a frequency of the line terminal, and A microcontroller comprising an electronic processor, the microcontroller configured to: A digital filter is applied to the line current measurement signal received from the current sensor, Determining a plurality of zero crossing locations of the line voltage measurement signal received from the zero crossing detection circuit, Counting a plurality of turning points of the filtered line current measurement signal, Determining a location of each turning point of the plurality of turning points relative to a corresponding zero crossing location of the plurality of zero crossing locations, Determining a time between each turning point of the plurality of turning points and a subsequent turning point of the plurality of turning points, Determining a local extremum derivative value around each of the plurality of inflection points, an Determining whether an arc fault exists within the circuit interrupting device based on the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and the local extremum derivative value around each turning point.
2. 2. The circuit interrupting device of claim 1, wherein the microcontroller is configured to: When an arc fault exists, an interruption device is activated.
3. 3. The circuit interrupting device of claim 1, wherein the microcontroller is configured to: Applying one or more thresholds to each of the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and the local extremum derivative value around each turning point, and The one or more thresholds are compared to each of the plurality of turning points, a location of each turning point relative to the corresponding zero crossing location, a time between each turning point and the subsequent turning point, and a local extremum derivative value around each turning point.
4. 4. The circuit interrupting device of claim 3, wherein the microcontroller is configured to: Determining whether the arc fault is present within the circuit interrupting device based on the comparison.
5. 5. A circuit interruption device according to claim 3 wherein the one or more thresholds are determined by a machine learning model stored in the memory of the microcontroller.
6. 6. The circuit interrupting device of claim 1, wherein the microcontroller is configured to: Developing a machine learning model based on the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and the local extremum derivative value around each turning point, and The machine learning model is applied to the circuit interrupting device.
7. 7. The circuit interrupting device of claim 6, wherein the microcontroller is configured to: determining whether the arc fault is present within the circuit interrupting device based on the machine learning model.
8. 8. The circuit interrupting device of claim 6, wherein the microcontroller is configured to: A probability of whether the arc fault is present within the circuit interrupting device is calculated based on the machine learning model.
9. 9. A method of detecting the presence of an arc fault occurring within a circuit including a line terminal, the method comprising: Applying, via a microcontroller comprising an electronic processor, a digital filter to a line current measurement signal received from a current sensor configured to measure a current flowing through the line terminal; Determining, via the microcontroller, a plurality of zero crossing locations of a line voltage measurement signal received from a zero crossing detection circuit configured to measure a voltage and frequency of the line terminal; counting a plurality of turning points of the filtered line current measurement signal via the microcontroller; Determining, via the microcontroller, a location of each turning point of the plurality of turning points relative to a corresponding zero crossing location of the plurality of zero crossing locations; determining, via the microcontroller, a time between each of the plurality of turning points and a subsequent turning point of the plurality of turning points; determining, via the microcontroller, local extremum derivative values around each of the plurality of turning points, and Determining, via the microcontroller, whether an arc fault exists within the circuit based on the plurality of turning points, a location of each turning point relative to the corresponding zero crossing location, a time between each turning point and the subsequent turning point, and a local extremum derivative value around each turning point.
10. 10. The method of claim 9, further comprising: when an arc fault is present, an interrupt device is activated via the microcontroller.
11. 11. The method of claim 9, further comprising: Applying one or more thresholds to each of the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and the local extremum derivative value around each turning point via the microcontroller, and The one or more thresholds are compared via the microcontroller with each of the plurality of turning points, a location of each turning point relative to the corresponding zero crossing location, a time between each turning point and the subsequent turning point, and a local extremum derivative value around each turning point.
12. 12. The method of claim 11, further comprising: Determining, via the microcontroller, whether the arc fault is present within the circuit based on the comparison.
13. 13. The method of claim 11, wherein the one or more thresholds are determined by a machine learning model stored in a memory of the microcontroller.
14. 14. The method of claim 9, further comprising: Developing a machine learning model based on the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and local extremum derivative values around each turning point via the microcontroller, and The machine learning model is applied to the circuit via the microcontroller.
15. 15. The method of claim 14, further comprising: determining, via the microcontroller, whether the arc fault is present within the circuit based on the machine learning model.
16. 16. The method of claim 14, further comprising: A probability of whether the arc fault is present within the circuit is calculated based on the machine learning model via the microcontroller.
17. 17. A system, comprising: A circuit interrupting device comprising: A line terminal; a current sensor configured to measure a current flowing through the line terminal; a zero crossing detection circuit configured to measure a voltage and a frequency of the line terminal, and A microcontroller comprising an electronic processor, the microcontroller configured to: Receiving a line current measurement signal from the current sensor; receiving a line voltage measurement signal from the zero crossing detection circuit; applying a digital filter to the line current measurement signal; Determining a plurality of zero crossing positions of the line voltage measurement signal; counting a plurality of turning points of the filtered line current measurement signal; Determining a location of each turning point of the plurality of turning points relative to a corresponding zero crossing location of the plurality of zero crossing locations; Determining a time between each turning point of the plurality of turning points and a subsequent turning point of the plurality of turning points; determining local extremum derivative values around each of the plurality of inflection points, and Determining whether an arc fault exists within the circuit interrupting device based on the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and the local extremum derivative value around each turning point.
18. 18. The system of claim 17, wherein the microcontroller is configured to: When an arc fault exists, an interruption device is activated.
19. 19. The system of claim 17, wherein the microcontroller is configured to: Applying one or more thresholds to each of the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and the local extremum derivative value around each turning point; Comparing the one or more thresholds with each of the plurality of turning points, a location of each turning point relative to the corresponding zero crossing location, a time between each turning point and the subsequent turning point, and a local extremum derivative value around each turning point, and Determining whether the arc fault is present within the circuit interrupting device based on the comparison.
20. 20. The system of claim 17, wherein the microcontroller is configured to: Developing a machine learning model based on the plurality of turning points, the location of each turning point relative to the corresponding zero crossing location, the time between each turning point and the subsequent turning point, and the local extremum derivative value around each turning point; Applying the machine learning model to the circuit interrupting device, and Determining whether the arc fault is present within the circuit interrupting device based on the machine learning model.

Description

System and method for detecting and identifying arcing based on discrete-time signal processing RELATED APPLICATIONS The present application claims priority from U.S. provisional patent application No. 63/589,478 filed on 10/11 of 2023, which is incorporated herein by reference in its entirety. Technical Field The present disclosure relates generally to switching electrical devices. More particularly, the present disclosure relates to circuit interrupting devices, such as arc fault circuit interrupter (arc fault circuit interrupter, AFCI) devices and/or ground fault circuit interrupter (ground fault circuit interrupter, GFCI) devices, that change from a "reset" or locked state to a "tripped" or unlocked state when one or more conditions are detected. Disclosure of Invention Switching electrical devices are installed in electrical panels and outlets to open electrical circuits in response to potentially damaging arc and fault conditions. When an arc condition or fault condition occurs, the switching electrical device acts as a circuit breaker to break electrical connections within the circuit to prevent damage to circuit components and potential injury to a user. In some cases, the switching electrical device may provide false detection of an arc condition or fault condition and break power through the circuit when no arc or fault is present. As a result, when the circuit experiences an electrical load that exhibits characteristics similar to an arc or fault condition (such as a combination of different electrical loads, inrush behavior of electrical loads, and turning on and off of electrical loads), it may be difficult for the switching electrical device to determine whether an arc and fault condition exists in the circuit. Therefore, a solution is needed to improve the reliability and accuracy of switching electrical devices in detecting arc and fault conditions. One aspect of the present disclosure provides a circuit interrupting device that includes a line terminal, a current sensor configured to measure a current flowing through the line terminal, a zero crossing detection circuit configured to measure a voltage and frequency of the line terminal, and a microcontroller including an electronic processor. The microcontroller is configured to apply a digital filter to the line current measurement signal received from the current sensor and to determine a plurality of zero crossing locations of the line voltage measurement signal received from the zero crossing detection circuit. The microcontroller is further configured to count a plurality of turning points of the filtered line current measurement signal, determine a location of each turning point of the plurality of turning points relative to a corresponding zero crossing location of the plurality of zero crossing locations, determine a time between each turning point of the plurality of turning points and a subsequent turning point of the plurality of turning points, and determine a local extremum derivative value around each turning point. The microcontroller is further configured to determine whether an arc fault exists within the circuit interrupting device based on the plurality of inflection points, the location of each inflection point relative to the corresponding zero crossing location, the time between each inflection point and a subsequent inflection point, and the local extremum derivative value around each inflection point. Another aspect of the present disclosure provides a method of detecting the presence of an arc fault occurring within a circuit including a line terminal. The method includes applying, via a microcontroller including an electronic processor, a digital filter to a line current measurement signal received from a current sensor configured to measure a current flowing through a line terminal, and determining, via the microcontroller, a plurality of zero crossing locations of the line voltage measurement signal received from a zero crossing detection circuit configured to measure a voltage and a frequency of the line terminal. The method further includes counting, via the microcontroller, a plurality of turning points of the filtered line current measurement signal, determining, via the microcontroller, a location of each turning point of the plurality of turning points relative to a corresponding zero-crossing location of the plurality of zero-crossing locations, determining, via the microcontroller, a time between each turning point of the plurality of turning points and a subsequent turning point of the plurality of turning points, and determining a local extremum derivative value around each turning point. The method further includes determining, via the microcontroller, whether an arc fault exists within the circuit interrupting device based on the plurality of inflection points, the location of each inflection point relative to the corresponding zero crossing location, the time between each inflection point and a subseq