GIS equipment internal metal dust detection system and detection method

Abstract

The invention discloses a system and a method for detecting metal dust in GIS (gas insulated switchgear) equipment, and belongs to the field of GIS equipment detection.The system comprises a light intensity sensor, a photon counting probe, a high-voltage power supply measuring end and an industrial personal computer, the light intensity sensor is used for collecting a light intensity signal generated in the movement process of metal dust in the GIS equipment, and the industrial personal computer outputs a PRPD atlas based on the collected light intensity signal after receiving a trigger signal; the photon counting probe is connected with the industrial personal computer through the counting plate, the photon counting probe is used for collecting photons generated in the movement process of the metal dust in the GIS equipment, and the industrial personal computer outputs a PRPC atlas based on collected photon signals after receiving the trigger signals. By adopting the detection system and the detection method for the metal dust in the GIS equipment, the metal dust in the GIS equipment can be detected in real time, and engineers are helped to evaluate the insulation state of the equipment and predict potential fault risks.

Description

Technical Field

[0001] The present invention relates to the technical field of GIS equipment detection, and in particular to a metal dust detection system and a detection method inside GIS equipment. Background Art

[0002] Metallic foreign matter may be generated during the entire life cycle of gas insulated switchgear (GIS), including production, operation, installation and maintenance. These metallic foreign matter come from a wide range of sources, and may be metal shavings left over from the production process, or metal particles generated during operation due to component wear or intrusion by external factors. The movement of metallic foreign matter inside the GIS or adsorption on the surface of its key components such as the basin insulator will cause local electric field distortion, thereby triggering gas breakdown, and may even cause flashover along the basin insulator, significantly reducing the operating reliability and safety of the equipment.

[0003] In view of this, the existing technology lacks effective detection means: At present, the existing technology is relatively scarce for the detection of metal dust inside GIS. Traditional detection methods mainly rely on regular power outages and manual inspections, which are not only inefficient but also unable to monitor the internal conditions of the equipment in real time. In addition, due to the complex structure of GIS equipment, many key parts are difficult to be thoroughly inspected by conventional means, resulting in the inability to timely discover and deal with potential hidden dangers. Summary of the invention

[0004] The purpose of the present invention is to provide a metal dust detection system and detection method inside GIS equipment to solve the above technical problems.

[0005] To achieve the above-mentioned purpose, the present invention provides a metal dust detection system inside GIS equipment, including a light intensity sensor, a photon counting probe, a high-voltage power supply measuring end and an industrial computer, wherein the high-voltage power supply measuring end is connected to the industrial computer, and the high-voltage power supply measuring end is used to provide a trigger signal;

[0006] The light intensity sensor is connected to the industrial computer via a data acquisition card. The light intensity sensor is used to collect the light intensity signal generated by the metal dust in the process of moving inside the GIS equipment. After receiving the trigger signal, the industrial computer analyzes the light intensity partial discharge phase distribution based on the collected light intensity signal and outputs the PRPD spectrum.

[0007] The photon counting probe is connected to the industrial computer via the counting board. The photon counting probe is used to collect photons generated by metal dust during the movement inside the GIS equipment. After receiving the trigger signal, the industrial computer analyzes the photon counting phase distribution based on the collected photon signal and outputs the PRPC spectrum.

[0008] Preferably, the counting board is a pulse counter, and the trigger end of the pulse counter is connected to the zero-crossing detection circuit via a single-chip microcomputer.

[0009] Preferably, the model of the photon counting probe is H8259-01, the model of the counting board is C8855-01; the model of the light intensity sensor is H10493-001, the data acquisition card is a four-channel data acquisition card, and the operation modes of the data acquisition card include data stream mode and trigger mode.

[0010] A method for detecting metal dust in a GIS equipment internal detection system comprises the following steps:

[0011] The light intensity sensor is used to collect the light intensity signal generated by the movement of metal dust inside the GIS equipment, and the light intensity signal is transmitted to the industrial computer using a data acquisition card, and the PRPD spectrum is generated using the industrial computer;

[0012] A photon counting probe is used to collect the photon signals synchronously generated by the metal powder during its movement inside the GIS equipment, and a 30ns continuous pulse is generated. The generated continuous pulses are then counted using a counting board, and the counting results are transmitted to an industrial computer. Finally, the PRPC spectrum is generated using the industrial computer.

[0013] Preferably, the specific steps for generating the PRPD spectrum are as follows:

[0014] Step 1: Set the sampling rate and trigger conditions: Set the signal sampling rate to 1M / s, and use the rising edge of the phase signal to trigger the acquisition. The trigger function is only used once during each acquisition process to ensure that the light intensity signal is aligned with the phase signal.

[0015] Step 2: Data stream mode acquisition: The data acquisition card used to collect light intensity signals executes the data stream mode and stores the collected data in the onboard memory;

[0016] Step 3: Data transmission loop: Based on the data transmission loop in the driver, the data in the onboard memory of the data acquisition card is continuously sent back to the industrial computer and stored in the queue;

[0017] Step 4: Start the synchronous processing loop: Use the light intensity signal peak search function to detect the peak value of the light intensity signal in the cache, record the amplitude of each peak value, and integrate the phase information corresponding to the peak value into the PRPD spectrum array;

[0018] At the same time, the phase signal processing function is used to cut and sort the collected phase signal, extract and calculate the phase information, and then pass the phase information to the light intensity signal peak search function;

[0019] Step 5: Integrate peak and phase information: Based on the light intensity signal peak search function processing array and the phase information returned by the phase signal processing function, the phase signal corresponding to the peak is synchronously integrated into the PRPD spectrum array;

[0020] Step 6: Output PRPD spectrum: visualize the integrated PRPD spectrum array as a PRPD spectrum and output it.

[0021] Preferably, the light intensity signal peak finding function is

[0022] The peak search function expression of the light intensity signal is as follows:

[0023] PeakIndexSet=i∣Ai]>A[i-1]and A[i]>A[i+1],1 <i<n-1 (1);

[0024]

[0025] In the formula, A[i], A[i-1], and A[i+1] represent three adjacent elements in the data array A, and i represents the index. It represents the phase degree of each point in a cycle, 360 represents a complete cycle, and f represents the frequency. represents the phase value corresponding to the peak point p, (i mod m) represents the remainder of the index i to the total data volume m;

[0026] The phase signal processing function expression is as follows:

[0027]

[0028] In the formula, xmod represents the phase value after being processed by the phase signal processing function, n represents the number of cycle repetitions, a represents the original phase value, Indicates the data point corresponding to the period.

[0029] Preferably, when the counting board is used to count the output pulses of the photon counting probe, the zero-crossing detection circuit is used to convert the sine wave of the trigger signal into a square wave, and then the square wave signal is connected to the single-chip microcomputer. The single-chip microcomputer detects the rising edge of the square wave and then outputs a TTL negative logic signal to trigger the counting board to start counting, and the PRPC spectrum is synthesized using the cache and data splicing method.

[0030] Preferably, the specific steps of synthesizing the PRPC map using the cache and data splicing method are as follows:

[0031] Step 1: Set the counting interval: Set the counting interval of the shortest pulse counting board to 50us in the Labview program;

[0032] Step 2: Data collection: Output an array of 500 data points every 0.025 seconds;

[0033] Step 3: Cache processing: store the collected data array into the queue;

[0034] Step 4: Data splicing: Take out multiple 0.025s data arrays from the queue and splice them into a 1s real-time photon count record;

[0035] Step 5: Data segmentation: The spliced ​​1s real-time photon count record is divided into data arrays of 50 power frequency cycle lengths. Each data array contains 400 data points, one of which represents 50us.

[0036] Step 6: Data superposition: superimpose the data points in the 50 power frequency cycle arrays to obtain the PRPC array;

[0037] Step 7. Display the results: Use Labview program to visualize the PRPC array and generate and display the PRPC spectrum.

[0038] Therefore, the present invention adopts the above-mentioned metal dust detection system and detection method inside GIS equipment, which has the following beneficial effects:

[0039] 1. High-precision detection: The light intensity sensor and photon counting probe collect light intensity signals and photon signals respectively, realizing multi-dimensional monitoring of the movement of metal dust inside the GIS equipment. This dual detection mechanism can capture the existence and distribution of metal dust more comprehensively and accurately;

[0040] 2. Real-time and high efficiency: Trigger signal synchronization: The trigger signal provided by the high-voltage power supply measurement end is connected to the industrial computer, ensuring the synchronous acquisition and processing of the light intensity signal and the photon signal, thereby improving the real-time and accuracy of data acquisition;

[0041] Data stream mode and trigger mode: The data acquisition card supports two operating modes, which can be flexibly selected in different application scenarios, ensuring the integrity of continuous data acquisition and performing efficient data trigger acquisition under specific conditions;

[0042] 3. Intelligent data analysis: By performing peak detection on the light intensity signal and combining it with phase information, the PRPD spectrum is automatically generated, which not only intuitively displays the phase distribution of partial discharge, but also provides an important visualization tool for fault diagnosis;

[0043] At the same time, the PRPC spectrum is synthesized by using the cache and data splicing methods to further analyze the photon counting phase distribution, thus enhancing the ability to identify the characteristics of partial discharge signals;

[0044] 4. Modular design: Each component in the system, such as light intensity sensor, photon counting probe, counting board, etc., is an independent module, which is easy to maintain and upgrade. In particular, the photon counting probe adopts the H8259-01 model and the counting board adopts the C8855-01 model. The selection of these high-precision components improves the overall performance of the system;

[0045] 5. Reliability and stability: The sine wave is converted into a square wave through the zero-crossing detection circuit, and the microcontroller detects the rising edge and outputs a TTL negative logic signal, ensuring the stability and accuracy of the trigger signal;

[0046] At the same time, based on the data transmission cycle in the driver, the data in the onboard memory of the data acquisition card is continuously sent back to the industrial computer and stored in the queue, which effectively avoids data loss and ensures the reliability of data transmission;

[0047] 6. Visualization and ease of use: Labview program is used for data acquisition, processing and spectrum display. It is simple and easy to use. Users can easily set parameters and view results, which improves the ease of use of the system.

[0048] In summary, the present invention has the characteristics of high precision, real-time, intelligence, modularity, reliability and ease of use, and has obvious technical advantages in the field of power equipment monitoring.

[0049] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The present invention is a principle block diagram of a metal dust detection system inside GIS equipment. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not used to limit the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0052] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or devices.

[0053] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0054] When metal foreign bodies move in GIS equipment, they will cause the electric field near them to be distorted. This process may be accompanied by gas ionization and local micro-discharge, resulting in an increase in the number of photons and the emission of light pulses. By synchronously measuring photon counting and light intensity signals, these changes in photons and light intensity can be captured, thereby realizing the detection of metal foreign bodies.

[0055] Based on the above analysis, the present invention is designed as follows: Figure 1 As shown, a metal dust detection system inside GIS equipment includes a light intensity sensor, a photon counting probe, a high-voltage power supply measuring end and an industrial computer, wherein the high-voltage power supply measuring end is connected to the industrial computer, and the high-voltage power supply measuring end is used to provide a trigger signal;

[0056] The light intensity sensor is connected to the industrial computer via a data acquisition card. The light intensity sensor is used to collect the light intensity signal generated by the metal dust in the process of moving inside the GIS equipment. After receiving the trigger signal, the industrial computer analyzes the light intensity partial discharge phase distribution based on the collected light intensity signal and outputs a PRPD (Phase-resolved Partial Discharge, PRPD light intensity partial discharge phase distribution) spectrum;

[0057] The photon counting probe is connected to the industrial computer through the counting board. The photon counting probe is used to collect photons generated by the movement of metal dust inside the GIS equipment. After receiving the trigger signal, the industrial computer analyzes the photon counting phase distribution based on the collected photon signal and outputs the PRPC (Phase-resolved Photon Counting, PRPC photon counting phase distribution) spectrum.

[0058] Preferably, the counting board is a pulse counter, and the trigger end of the pulse counter is connected to the zero-crossing detection circuit via a single-chip microcomputer.

[0059] Preferably, the model of the photon counting probe is H8259-01. Specifically, the photon counting module adopts the H8259-01 photon counting module of Songbin Optics, which is a photon counting head device, which includes a 28mm diameter side window type photomultiplier tube, a high-speed photon counting circuit and a high-voltage power supply circuit. Due to thermal noise, photomultiplier tubes with higher sensitivity in the near-infrared region usually have larger dark counts, but since low-noise photomultiplier tubes are selected, high signal-to-noise ratio measurements can be obtained. The high-voltage power supply and discrimination level of the photomultiplier tube have been preset according to the optimal value, and photon counting measurement can be performed by connecting a +5V power supply. After receiving the photon, the module converts the optical signal into an electrical pulse signal, each photon corresponds to a pulse, the pulse width is 30ns, and the typical value of the output pulse height is 2.2V. The model of the counting board is C8855-01, which has two counting circuits, which can count the input signal without any dead time. In addition, the counting board is equipped with a trigger interface to receive a TTL negative logic signal trigger. The model of the light intensity sensor is H10493-001. Specifically, the light intensity module uses the H10493-001 photomultiplier tube module of Hamamatsu Optics, which consists of a 28mm diameter end-window type photomultiplier tube, a high-voltage power supply and a low-noise amplifier. Due to the wide light-receiving surface with a diameter of 25mm, light can be collected effectively. Amplifiers with current-to-voltage conversion coefficients of 1V / μA or 0.1V / μA and frequency bands of DC to 20kHz, DC to 200kHz or DC to 8MHz are available. Photomultiplier tubes with different spectral sensitivity characteristics are provided for measurement in the visible light range or UV to near-infrared range. The module can realize real-time measurement of light intensity and convert light intensity signals into voltage signals. The maximum value of ripple noise (peak to peak) is 0.6mV. By controlling its sensitivity input voltage value, its voltage conversion coefficient can be adjusted to adjust its sensitivity. Comparing the photon signal and the light intensity signal can be used to distinguish between ionization luminescence and micro-discharge luminescence. The data acquisition card is a four-channel data acquisition card, and the operation modes of the data acquisition card include data stream mode and trigger mode. Specifically, the data acquisition card uses Picoscope's four-channel high-speed acquisition card 2408B, which can provide fast real-time sampling rate, up to 1GS / s on a single analog channel. This sampling rate means that the timing resolution is 1ns. The data acquisition card has two operation modes, streaming mode and block mode. In the data stream mode, the data acquisition card continuously collects data into the acquisition card's onboard memory, and its supporting Labview-based driver software continuously transmits the data in the onboard memory back to the industrial computer. In this operation mode, due to the limited onboard memory capacity, the data acquisition card has an upper limit on the sampling rate. If the sampling rate is too high and the data volume is too large, the onboard memory may overflow, resulting in data loss.In trigger mode, the data acquisition card will start collecting data through the set specific trigger signal. After the onboard memory is full, the data will be transmitted back to the industrial computer for processing. After the industrial computer completes processing the data in the onboard memory, it will send a completion flag to the acquisition card to drive the acquisition card to wait for the trigger signal to start collecting again. Compared with the stream mode, this mode adds the setting of the trigger signal. Before starting to collect data each time, you need to wait for the trigger signal. Both the data stream mode and the trigger mode can achieve seamless data collection.

[0060] A method for detecting metal dust in a GIS equipment internal detection system comprises the following steps:

[0061] The light intensity sensor is used to collect the light intensity signal generated by the movement of metal dust inside the GIS equipment, and the light intensity signal is transmitted to the industrial computer using a data acquisition card, and the PRPD spectrum is generated using the industrial computer;

[0062] Specifically, the steps for generating the PRPD map are as follows:

[0063] Step 1: Set the sampling rate and trigger conditions: Set the signal sampling rate to 1M / s, and use the rising edge of the phase signal to trigger the acquisition. The trigger function is only used once during each acquisition process to ensure that the light intensity signal is aligned with the phase signal.

[0064] Step 2: Data stream mode acquisition: The data acquisition card used to collect light intensity signals executes the data stream mode and stores the collected data in the onboard memory;

[0065] Step 3, data transmission loop: Based on the data transmission loop in the driver (the program consists of data acquisition loop, data processing loop and cache part. Among them, the data acquisition loop will continuously transmit the data collected by the data acquisition card back to the industrial computer, and the returned data will be temporarily stored in the data cache and finally completed by the data processing loop. The data processing speeds of the two data loops need to match. If the data output speed of the data acquisition loop is higher than the data processing speed of the data processing loop, it will cause cache overflow), the data in the onboard memory of the data acquisition card is continuously sent back to the industrial computer and stored in the queue;

[0066] Step 4: Start the synchronous processing loop: Use the light intensity signal peak search function to detect the peak value of the light intensity signal in the cache, record the amplitude of each peak value, and integrate the phase information corresponding to the peak value into the PRPD spectrum array;

[0067] At the same time, the phase signal processing function is used to cut and sort the collected phase signal, extract and calculate the phase information, and then pass the phase information to the light intensity signal peak search function;

[0068] Step 5: Integrate peak and phase information: Based on the light intensity signal peak search function processing array and the phase information returned by the phase signal processing function, the phase signal corresponding to the peak is synchronously integrated into the PRPD spectrum array;

[0069] Step 6: Output PRPD spectrum: visualize the integrated PRPD spectrum array as a PRPD spectrum and output it.

[0070] Among them, the peak search function of the light intensity signal is

[0071] The peak search function expression of the light intensity signal is as follows:

[0072] PeakIndexSet=i∣Ai]>A[i-1]and A[i]>A[i+1],1 <i<n-1 (1);

[0073]

[0074] In the formula, A[i], A[i-1], and A[i+1] represent three adjacent elements in the data array A, and i represents the index. It represents the phase degree of each point in a cycle, 360 represents a complete cycle, and f represents the frequency. represents the phase value corresponding to the peak point p, (i mod m) represents the remainder of the index i to the total data volume m;

[0075] The phase signal processing function expression is as follows:

[0076]

[0077] In the formula, xmod represents the phase value after being processed by the phase signal processing function, n represents the number of cycle repetitions, a represents the original phase value, Indicates the data point corresponding to the period.

[0078] A photon counting probe is used to collect the photon signals synchronously generated by the metal powder during its movement inside the GIS equipment, and a 30ns continuous pulse is generated. The generated continuous pulses are then counted using a counting board, and the counting results are transmitted to an industrial computer. Finally, the PRPC spectrum is generated using the industrial computer.

[0079] When the counting board is used to count the output pulses of the photon counting probe, the zero-crossing detection circuit is used to convert the sine wave of the trigger signal into a square wave, and then the square wave signal is connected to the microcontroller. The microcontroller detects the rising edge of the square wave and then outputs a TTL negative logic signal to trigger the counting board to start counting, and the PRPC spectrum is synthesized using the cache and data splicing method.

[0080] Preferably, the specific steps of synthesizing the PRPC map using the cache and data splicing method are as follows:

[0081] Step 1: Set the counting interval: Set the counting interval of the shortest pulse counting board to 50us in the Labview program;

[0082] Step 2: Data collection: Output an array of 500 data points every 0.025 seconds;

[0083] Step 3: Cache processing: store the collected data array into the queue;

[0084] Step 4: Data splicing: Take out multiple 0.025s data arrays from the queue and splice them into a 1s real-time photon count record;

[0085] Step 5: Data segmentation: The spliced ​​1s real-time photon count record is divided into data arrays of 50 power frequency cycle lengths. Each data array contains 400 data points, one of which represents 50us.

[0086] Step 6: Data superposition: superimpose the data points in the 50 power frequency cycle arrays to obtain the PRPC array;

[0087] Step 7. Display the results: Use Labview program to visualize the PRPC array and generate and display the PRPC spectrum.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A metal dust detection system inside GIS equipment, characterized by: It includes a light intensity sensor, a photon counting probe, a high-voltage power supply measuring end and an industrial computer, wherein the high-voltage power supply measuring end is connected to the industrial computer, and the high-voltage power supply measuring end is used to provide a trigger signal; The light intensity sensor is connected to the industrial computer via a data acquisition card. The light intensity sensor is used to collect the light intensity signal generated by the metal dust in the process of moving inside the GIS equipment. After receiving the trigger signal, the industrial computer analyzes the light intensity partial discharge phase distribution based on the collected light intensity signal and outputs the PRPD spectrum. The photon counting probe is connected to the industrial computer via the counting board. The photon counting probe is used to collect photons generated by metal dust during the movement inside the GIS equipment. After receiving the trigger signal, the industrial computer analyzes the photon counting phase distribution based on the collected photon signal and outputs the PRPC spectrum.

2. A metal dust detection system inside GIS equipment according to claim 1, characterized in that: The counting board is a pulse counter, and the trigger end of the pulse counter is connected to the zero-crossing detection circuit via the single-chip microcomputer.

3. A metal dust detection system inside GIS equipment according to claim 2, characterized in that: The model of the photon counting probe is H8259-01, the model of the counting board is C8855-01; the model of the light intensity sensor is H10493-001, the data acquisition card is a four-channel data acquisition card, and the operation modes of the data acquisition card include data stream mode and trigger mode.

4. A detection method for a metal dust detection system inside a GIS device as described in any one of claims 1 to 3, characterized in that: The following steps are involved: The light intensity sensor is used to collect the light intensity signal generated by the movement of metal dust inside the GIS equipment, and the light intensity signal is transmitted to the industrial computer using a data acquisition card, and the PRPD spectrum is generated using the industrial computer; A photon counting probe is used to collect the photon signals synchronously generated by the metal powder during its movement inside the GIS equipment, and a 30ns continuous pulse is generated. The generated continuous pulses are then counted using a counting board, and the counting results are transmitted to an industrial computer. Finally, the PRPC spectrum is generated using the industrial computer.

5. The detection method of a metal dust detection system inside GIS equipment according to claim 4, characterized in that: The specific steps for generating the PRPD map are as follows: Step 1: Set the sampling rate and trigger conditions: Set the signal sampling rate to 1M / s, and use the rising edge of the phase signal to trigger the acquisition. The trigger function is only used once during each acquisition process to ensure that the light intensity signal is aligned with the phase signal. Step 2: Data stream mode acquisition: The data acquisition card used to collect light intensity signals executes the data stream mode and stores the collected data in the onboard memory; Step 3: Data transmission loop: Based on the data transmission loop in the driver, the data in the onboard memory of the data acquisition card is continuously sent back to the industrial computer and stored in the queue; Step 4: Start the synchronous processing loop: Use the light intensity signal peak search function to detect the peak value of the light intensity signal in the cache, record the amplitude of each peak value, and integrate the phase information corresponding to the peak value into the PRPD spectrum array; At the same time, the phase signal processing function is used to cut and sort the collected phase signal, extract and calculate the phase information, and then pass the phase information to the light intensity signal peak search function; Step 5: Integrate peak and phase information: Based on the light intensity signal peak search function processing array and the phase information returned by the phase signal processing function, the phase signal corresponding to the peak is synchronously integrated into the PRPD spectrum array; Step 6: Output PRPD spectrum: visualize the integrated PRPD spectrum array as a PRPD spectrum and output it.

6. The detection method of the metal dust detection system inside GIS equipment according to claim 5 is characterized by: The peak search function of the light intensity signal is: The peak search function expression of the light intensity signal is as follows: PeakIndexSet=i∣Ai]>A[i-1 ] andA[i]>A[i+1],1<i<n-1 (1); In the formula, A[i], A[i-1], and A[i+1] represent three adjacent elements in the data array A, and i represents the index. It represents the phase degree of each point in a cycle, 360 represents a complete cycle, and f represents the frequency. represents the phase value corresponding to the peak point p, (i mod m) represents the remainder of the index i to the total data volume m; The phase signal processing function expression is as follows: Where xmod represents the phase value after being processed by the phase signal processing function, n represents the number of cycle repetitions, a represents the original phase value, and φ represents the period corresponding to the data point.

7. The detection method of a metal dust detection system inside GIS equipment according to claim 4, characterized in that: When the counting board is used to count the output pulses of the photon counting probe, the zero-crossing detection circuit is used to convert the sine wave of the trigger signal into a square wave, and then the square wave signal is connected to the microcontroller. The microcontroller detects the rising edge of the square wave and then outputs a TTL negative logic signal to trigger the counting board to start counting, and the PRPC spectrum is synthesized using the cache and data splicing method.

8. The detection method of the metal dust detection system inside GIS equipment according to claim 7 is characterized by: The specific steps of synthesizing the PRPC map using the cache and data splicing method are as follows: Step 1: Set the counting interval: Set the counting interval of the shortest pulse counting board to 50us in the Labview program; Step 2: Data collection: Output an array of 500 data points every 0.025 seconds; Step 3: Cache processing: store the collected data array into the queue; Step 4: Data splicing: Take out multiple 0.025s data arrays from the queue and splice them into a 1s real-time photon count record; Step 5: Data segmentation: The spliced ​​1s real-time photon count record is divided into data arrays of 50 power frequency cycle lengths. Each data array contains 400 data points, one of which represents 50us. Step 6: Data superposition: superimpose the data points in the 50 power frequency cycle arrays to obtain the PRPC array; Step 7. Display the results: Use Labview program to visualize the PRPC array and generate and display the PRPC spectrum.

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