Switch cabinet internal fault arc detection method based on multi-signal fusion

Abstract

The application relates to the technical field of switch cabinet maintenance, and discloses a switch cabinet internal fault arc detection method based on multi-signal fusion, which comprises the following steps: step one, arranging multiple types of sensing and collecting components; step two, synchronously collecting switch cabinet operation multi-dimensional original signals in channels; step three, filtering various interference signals in layers; step four, independently identifying various effective characteristic signals after preprocessing; step five, constructing multi-signal fusion discrimination logic; step six, completing fault arc type positioning in stages; step seven, layer-by-layer outputting protection action instructions; step eight, synchronously generating fault early warning and state alarm information; step nine, storing full-process detection data; and step ten, periodically self-checking and calibrating sensing links and discrimination logic. The switch cabinet internal fault arc detection method based on multi-signal fusion greatly reduces the misoperation risk caused by single optical detection by relying on multi-signal fusion discrimination, and takes into account fault rapid removal and early hidden danger early warning.

Description

Technical Field

[0001] This invention relates to the field of switchgear maintenance technology, specifically to a method for detecting internal fault arcs in switchgear based on multi-signal fusion. Background Technology

[0002] Short circuits in the busbars, cable compartments, and switch compartments of medium and low voltage switchgear can easily generate fault arcs. The high-temperature shockwaves from these arcs can damage the cabinet and transformers, while also threatening the safety of maintenance personnel. Existing conventional arc protection systems often employ a single optical criterion. Internal switchgear lighting, strong light from maintenance checks, and visible light from minor flashovers of insulators can easily cause malfunctions. Some dual-criteria schemes rely on single-criteria signal acquisition, failing to detect latent faults such as partial discharges in advance. Furthermore, their fault location accuracy is insufficient, and their tripping levels are limited. After fault clearance, they cannot trigger the upstream circuit breaker, easily expanding the fault's impact range. Simultaneously, existing detection schemes lack a periodic self-checking mechanism for the hardware link, failing to promptly detect sensor disconnections and abnormal acquisition circuits, posing a potential risk of protection failure. Summary of the Invention

[0003] (a) Technical problems to be solved: To address the shortcomings of existing technologies, this invention provides a multi-signal fusion-based method for detecting internal fault arcs in switchgear. This method significantly reduces the risk of maloperation caused by single optical detection by relying on multi-signal fusion for discrimination, while also ensuring rapid fault clearing and early warning of potential hazards. It is adaptable to various medium and low voltage switchgear busbar and feeder interval arc protection scenarios, has strong anti-electromagnetic interference capabilities, and significantly improves protection reliability and comprehensive fault handling. This method solves the problems mentioned in the background technology.

[0004] (II) Technical Solution: To achieve the above objectives, the present invention provides the following technical solution: a method for detecting internal fault arcs in switchgear based on multi-signal fusion, comprising the following steps: Step 1: Deploy multiple types of sensing and acquisition components. Arrive arc sensing units, current acquisition units, voltage acquisition units, and temperature sensing units in the corresponding protection areas of each independent chamber of the switch cabinet. Each sensing unit establishes a signal transmission link with the main control protection device through an independent transmission channel. Step 2: Synchronously collect multi-dimensional raw signals of switchgear operation through different channels. The arc light sensing unit collects optical signals inside the chamber, the current acquisition unit collects bus and feeder circuit current signals, the voltage acquisition unit collects bus voltage signals, and the temperature sensing unit collects temperature signals at each monitoring point inside the cabinet. All signals are synchronously transmitted to the main control protection device to complete signal preprocessing. Step 3: Filter out various interference signals in layers. Perform spectral screening on optical signals to filter out visible light interference from the environment. Filter out load fluctuations and conventional harmonic interference from current and voltage signals. Remove steady-state temperature drift interference caused by environmental temperature changes from temperature signals. Extract effective feature signals that are only related to fault arcs. Step 4: Independently identify the various types of effective feature signals after preprocessing, and determine whether the optical signal reaches the arc fault light intensity feature threshold, whether the current signal shows short circuit overcurrent characteristics, whether the voltage signal shows fault distortion characteristics, and whether the temperature signal shows abnormal temperature rise characteristics. Step 5: Construct multi-signal fusion discrimination logic, couple and match optical features, current features, voltage features, and temperature features, and divide them into three types of fusion judgment modes: single-signal independent discrimination, dual-signal combination discrimination, and multi-signal collaborative discrimination. Step 6: Complete the fault arc type location in stages. Based on the source of characteristic signals uploaded by the sensing units of different chambers, match the preset area logical mapping relationship to lock the specific interval location of the switchgear that generated the fault arc. Step 7: Output protection action commands in layers. If a single optical signal meets the fault characteristic judgment conditions, output a first-level instantaneous trip action command; if the optical signal and the current or voltage signal synchronously meet the fault characteristic judgment conditions, output a second-level coordinated trip command; if multiple signals synchronously trigger the fault characteristics and the fault is not eliminated by a single trip, output a three-level cascading trip of the upper-level circuit breaker with a delay action command. Step 8: Synchronously generate fault warning and status alarm information. When any of the following hidden danger signals are detected: partial discharge dim light characteristics, sensor link abnormality, voltage circuit disconnection, or temperature exceeding the limit, an early warning alarm signal is output independently. It does not trigger a trip but only uploads operation and maintenance prompt information. Step 9: Store the entire process of detection data, and fully record the signal acquisition timing, interference filtering process, fusion discrimination logic, fault location results, protection action output records, and pre-warning alarm records to form a traceable event archive; Step 10: Periodically self-test and calibrate the sensing link and discrimination logic, periodically verify the integrity of the transmission channel of each sensing unit, the accuracy of signal acquisition, and the fusion discrimination threshold parameters. When a hardware link fault or parameter deviation is detected, lock out the entire protection system and output an abnormal alarm.

[0005] Preferably, the arc light sensing unit in step one adopts an ultraviolet band photosensitive acquisition structure, which only collects the ultraviolet light signal specific to arc faults and isolates visible light signals such as cabinet lighting and inspection strong light.

[0006] Preferably, in step two, each sensing unit uses optical fiber transmission to upload signals, and the photoelectric conversion process is completed within the main control and protection device to avoid signal distortion caused by the strong electromagnetic environment inside the cabinet.

[0007] Preferably, the optical signal interference filtering process in step three includes a real-time low-light monitoring process to continuously capture weak light signals of partial discharge inside the switch cabinet and identify potential arc fault hazards in advance.

[0008] Preferably, the fusion discrimination logic in step five supports custom logic mapping relationships, and can configure matching current and voltage signal associated objects for each arc light sensing unit to achieve selective protection discrimination by interval.

[0009] Preferably, the three-level trip delay action command in step seven is activated only when the fault characteristic signal still exists after the first and second level trip actions are completed, and the delay duration is customized according to the on-site power supply system operation requirements.

[0010] Preferably, in step eight, various warning and alarm signals are stored separately and archived separately from fault trip records, so that the operation and maintenance terminal can retrieve the hidden danger warning files and the accident trip files respectively.

[0011] Preferably, the test files stored in step nine support external communication and can be uploaded to the station's integrated monitoring system through multiple standard communication protocols to simultaneously complete time synchronization calibration.

[0012] Preferably, the self-test calibration process in step ten includes an automatic sensor disconnection detection function, which immediately outputs an alarm for the corresponding channel when the transmission link of any arc light sensing unit is interrupted.

[0013] Preferably, the entire detection method is equipped with a modular hardware architecture, and a single main control device can connect to multiple arc light sensing units. When the sensing points exceed the capacity of a single unit, an expansion unit is added to expand the acquisition channels, while maintaining the unified and unchanged logic of multi-signal fusion and discrimination.

[0014] (III) Beneficial Effects: Compared with existing technologies, this invention provides a method for detecting internal fault arcs in switchgear based on multi-signal fusion, which has the following advantages: 1. This method for detecting internal fault arcs in switchgear based on multi-signal fusion uses ultraviolet arc light acquisition combined with current, voltage, and temperature multi-signal fusion discrimination to filter out ambient visible light interference from the source, significantly reducing the probability of protection maloperation and improving detection reliability; 2. This method for detecting internal fault arcs in switchgear based on multi-signal fusion adds multiple early warning functions such as low-light monitoring, temperature exceeding limits, PT disconnection, and sensor disconnection. It can capture latent defects before the arc fault occurs, arrange equipment maintenance in advance, and avoid accidents. 3. This method for detecting internal fault arcs in switchgear based on multi-signal fusion divides the trip logic into three levels, enables rapid fault clearing with instantaneous tripping, and prevents the fault from continuing to expand with a tripping mechanism, thus balancing action speed and system operation stability. Attached Figure Description

[0015] Figure 1 This is a flowchart of the internal fault arc detection method for switchgear based on multi-signal fusion proposed in this invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 A method for detecting internal fault arcs in switchgear based on multi-signal fusion includes the following steps: Step 1: Deploy multiple types of sensing and acquisition components. Arclight sensing units, current acquisition units, voltage acquisition units, and temperature sensing units are respectively deployed in the corresponding protection areas inside each independent chamber of the switchgear. Each sensing unit establishes a signal transmission link with the main control protection device through an independent transmission channel. The arclight sensing unit adopts an ultraviolet band photosensitive acquisition structure to collect only the ultraviolet light signal specific to arc faults and isolate visible light signals such as cabinet lighting and inspection strong light. Step 2: Multi-dimensional raw signals of switchgear operation are collected synchronously through different channels. The arc light sensing unit collects optical signals inside the chamber, the current acquisition unit collects bus and feeder circuit current signals, the voltage acquisition unit collects bus voltage signals, and the temperature sensing unit collects temperature signals at each monitoring point inside the cabinet. All signals are transmitted synchronously to the main control and protection device for signal preprocessing. Each sensing unit uses fiber optic transmission to upload signals. The photoelectric conversion process is completed within the main control and protection device to avoid signal distortion caused by the strong electromagnetic environment inside the cabinet. Step 3: Layered filtering of various interference signals. Optical signals are filtered to remove visible light interference from the environment. Current and voltage signals are filtered to remove load fluctuations and conventional harmonic interference. Temperature signals are filtered to remove steady-state temperature drift interference caused by environmental temperature changes. Effective feature signals related only to fault arcs are extracted. The optical signal interference filtering process includes a real-time low-light monitoring process to continuously capture weak light signals of partial discharge inside the switch cabinet and identify potential arc fault hazards in advance. Step 4: Independently identify the various types of effective feature signals after preprocessing, and determine whether the optical signal reaches the arc fault light intensity feature threshold, whether the current signal shows short circuit overcurrent characteristics, whether the voltage signal shows fault distortion characteristics, and whether the temperature signal shows abnormal temperature rise characteristics. Step 5: Construct multi-signal fusion discrimination logic, couple and match optical features, current features, voltage features, and temperature features, and divide them into three types of fusion judgment modes: single signal independent discrimination, dual signal combination discrimination, and multi-signal collaborative discrimination. The fusion discrimination logic supports custom logic mapping relationships, and can configure matching current and voltage signal association objects separately for each arc light sensing unit to achieve selective protection discrimination by interval. Step 6: Complete the fault arc type location in stages. Based on the source of characteristic signals uploaded by the sensing units of different chambers, match the preset area logical mapping relationship to lock the specific interval location of the switchgear that generated the fault arc. Step 7: Output protection action commands in layers. If a single optical signal meets the fault characteristic judgment conditions, output a first-level instantaneous trip command. If the optical signal and the current or voltage signal synchronously meet the fault characteristic judgment conditions, output a second-level coordinated trip command. If multiple signals synchronously trigger the fault characteristics and the fault is not eliminated by a single trip, output a three-level cascading trip command with a delay. The three-level cascading trip command with a delay is only activated when the fault characteristic signal still exists after the first and second-level trips are completed. The delay duration is customizable according to the on-site power supply system operation requirements. Step 8: Synchronously generate fault warning and status alarm information. When any of the following hidden danger signals are detected: partial discharge dim light characteristics, sensor link abnormality, voltage circuit disconnection, or temperature exceeding the limit, an early warning alarm signal is output independently. It does not trigger a trip but only uploads operation and maintenance prompt information. Various early warning alarm signals are stored separately and archived separately from fault trip records. The operation and maintenance terminal can retrieve hidden danger warning files and accident trip files separately. Step 9: Store the entire process of detection data, fully record the signal acquisition timing, interference filtering process, fusion discrimination logic, fault location results, protection action output records, and pre-warning alarm records, forming a traceable event archive. The detection archive stored in the archive supports external communication and can be connected to the station's integrated monitoring system through multiple standard communication protocols to simultaneously complete time synchronization calibration. Step 10: Periodically self-test and calibrate the sensing link and discrimination logic. Regularly verify the integrity of the transmission channel of each sensing unit, the signal acquisition accuracy, and the fusion discrimination threshold parameters. When a hardware link fault or parameter deviation is detected, lock the entire protection system and output an abnormal device alarm. The self-test calibration process includes an automatic sensor disconnection detection function. When the transmission link of any arc light sensing unit is interrupted, the corresponding channel alarm is output immediately. The entire detection method is equipped with a modular hardware architecture. A single main control device can connect to multiple arc light sensing units. When the sensing points exceed the capacity of a single unit, an expansion unit is added to expand the acquisition channels, while maintaining the unified and unchanged multi-signal fusion discrimination logic.

[0018] It should be noted that the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0019] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for detecting internal fault arcs in switchgear based on multi-signal fusion, comprising the following steps: Step 1: Deploy multiple types of sensing and acquisition components. Arrive arc sensing units, current acquisition units, voltage acquisition units, and temperature sensing units in the corresponding protection areas of each independent chamber of the switch cabinet. Each sensing unit establishes a signal transmission link with the main control protection device through an independent transmission channel. Step 2: Synchronously collect multi-dimensional raw signals of switchgear operation through different channels. The arc light sensing unit collects optical signals inside the chamber, the current acquisition unit collects bus and feeder circuit current signals, the voltage acquisition unit collects bus voltage signals, and the temperature sensing unit collects temperature signals at each monitoring point inside the cabinet. All signals are synchronously transmitted to the main control protection device to complete signal preprocessing. Step 3: Filter out various interference signals in layers. Perform spectral screening on optical signals to filter out visible light interference from the environment. Filter out load fluctuations and conventional harmonic interference from current and voltage signals. Remove steady-state temperature drift interference caused by environmental temperature changes from temperature signals. Extract effective feature signals that are only related to fault arcs. Step 4: Independently identify the various types of effective feature signals after preprocessing, and determine whether the optical signal reaches the arc fault light intensity feature threshold, whether the current signal shows short circuit overcurrent characteristics, whether the voltage signal shows fault distortion characteristics, and whether the temperature signal shows abnormal temperature rise characteristics. Step 5: Construct multi-signal fusion discrimination logic, couple and match optical features, current features, voltage features, and temperature features, and divide them into three types of fusion judgment modes: single-signal independent discrimination, dual-signal combination discrimination, and multi-signal collaborative discrimination. Step 6: Complete the fault arc type location in stages. Based on the source of characteristic signals uploaded by the sensing units of different chambers, match the preset area logical mapping relationship to lock the specific interval location of the switchgear that generated the fault arc. Step 7: Output protection action commands in layers. If a single optical signal meets the fault characteristic judgment conditions, output a first-level instantaneous trip action command; if the optical signal and the current or voltage signal synchronously meet the fault characteristic judgment conditions, output a second-level coordinated trip command; if multiple signals synchronously trigger the fault characteristics and the fault is not eliminated by a single trip, output a three-level cascading trip of the upper-level circuit breaker with a delay action command. Step 8: Synchronously generate fault warning and status alarm information. When any of the following hidden danger signals are detected: partial discharge dim light characteristics, sensor link abnormality, voltage circuit disconnection, or temperature exceeding the limit, an early warning alarm signal is output independently. It does not trigger a trip but only uploads operation and maintenance prompt information. Step 9: Store the entire process of detection data, and fully record the signal acquisition timing, interference filtering process, fusion discrimination logic, fault location results, protection action output records, and pre-warning alarm records to form a traceable event archive; Step 10: Periodically self-test and calibrate the sensing link and discrimination logic, periodically verify the integrity of the transmission channel of each sensing unit, the accuracy of signal acquisition, and the fusion discrimination threshold parameters. When a hardware link fault or parameter deviation is detected, lock out the entire protection system and output a device abnormality alarm.

2. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, The arc light sensing unit described in step one adopts an ultraviolet band photosensitive acquisition structure, which only collects ultraviolet light signals specific to arc faults and isolates visible light signals such as cabinet lighting and inspection strong light.

3. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, In step two, each sensing unit uses fiber optic transmission to upload signals, and the photoelectric conversion process is completed within the main control and protection device to avoid signal distortion caused by the strong electromagnetic environment inside the cabinet.

4. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, Step three, the optical signal interference filtering process, includes a real-time low-light monitoring process to continuously capture weak light signals of partial discharge inside the switch cabinet and identify potential arc fault hazards in advance.

5. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, In step five, the fusion discrimination logic supports custom logic mapping relationships. It can configure matching current and voltage signal associated objects for each arc light sensing unit to achieve selective protection discrimination by interval.

6. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, In step seven, the three-level trip delay action command is only activated when the fault characteristic signal still exists after the first and second level trip actions are completed. The delay duration is customized according to the on-site power supply system operation requirements.

7. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, In step eight, various warning and alarm signals are stored separately and archived separately from fault trip records. The maintenance team can retrieve the hidden danger warning files and the accident trip files separately.

8. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, The test files stored in step nine support external communication and can be uploaded to the station's integrated monitoring system through various standard communication protocols to simultaneously complete time synchronization calibration.

9. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, Step 10 of the self-test calibration process includes an automatic sensor disconnection detection function, which immediately outputs an alarm for the corresponding channel when the transmission link of any arc light sensing unit is interrupted.

10. The method for detecting internal fault arcs in switchgear based on multi-signal fusion according to claim 1, characterized in that, The entire detection method is equipped with a modular hardware architecture. A single main control device can connect to multiple arc light sensing units. When the sensing points exceed the capacity of a single device, an expansion unit is added to expand the acquisition channels, while maintaining the unified and unchanged logic of multi-signal fusion and discrimination.

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