Partial discharge double-end positioning method and device, computer equipment, readable storage medium and program product

Abstract

This application relates to a method, apparatus, computer device, computer-readable storage medium, and computer program product for dual-end partial discharge localization. The method includes: receiving a first discharge pulse frame transmitted by a first acquisition unit, and a second discharge pulse frame transmitted by at least one adjacent second acquisition unit; locating a partial discharge signal from the first discharge pulse frame to obtain a first peak time of the partial discharge signal; extracting feature information of the partial discharge signal from the first discharge pulse frame, and locating the partial discharge signal from the second discharge pulse frame based on the feature information to obtain a second peak time of the partial discharge signal; and determining the partial discharge location based on first cable positioning information corresponding to the first acquisition unit, second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time. This method can improve detection sensitivity.

Description

Technical Field

[0001] This application relates to the field of partial discharge detection technology, and in particular to a method, apparatus, computer device, computer-readable storage medium, and computer program product for dual-end localization of partial discharge. Background Technology

[0002] Partial discharge is a phenomenon in which a non-penetrating discharge occurs in a localized area of ​​an insulating medium under the influence of an electric field. Although the energy of this discharge is relatively small, its long-term presence can gradually erode the insulating material, eventually leading to insulation failure or even equipment damage. Therefore, accurate detection and location of partial discharges are crucial for ensuring the safe operation of power cables.

[0003] In traditional technology, partial discharge localization mainly adopts dual-end localization technology. This technology requires the use of acquisition devices deployed at both ends of the cable to capture partial discharge signals separately. The partial discharge is then located by comparing the time difference between the signals captured at both ends.

[0004] However, the detection sensitivity of traditional dual-end positioning technology is low, requiring both ends to collect strong partial discharge signals for positioning. If the partial discharge signal of the cable body is weak or the environmental interference is large, causing one end to be unable to identify the partial discharge signal, partial discharge positioning cannot be achieved. Summary of the Invention

[0005] Therefore, it is necessary to provide a partial discharge dual-end positioning method, device, computer equipment, computer-readable storage medium, and computer program product that can improve detection sensitivity in response to the above-mentioned technical problems.

[0006] In a first aspect, this application provides a method for locating partial discharge at both ends, including:

[0007] The system receives a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event, which is triggered by the first acquisition unit when it detects a partial discharge signal.

[0008] The partial discharge signal is located from the first discharge pulse frame, and the first peak time of the partial discharge signal is obtained.

[0009] Feature information of the partial discharge signal is extracted from the first discharge pulse frame, and the partial discharge signal is located from the second discharge pulse frame based on the feature information to obtain the second peak time of the partial discharge signal.

[0010] The location of partial discharge is determined based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

[0011] In one embodiment, the method is applied to a partial discharge dual-end positioning system, which includes a measurement host and multiple acquisition units, each acquisition unit including a first acquisition unit and at least one second acquisition unit adjacent to the first acquisition unit.

[0012] Before receiving the first discharge pulse frame sent by the first acquisition unit, the method further includes:

[0013] When a partial discharge signal with an amplitude exceeding a preset voltage threshold is detected by the first acquisition unit, a partial discharge location event is triggered. The partial discharge detection time corresponding to the partial discharge signal is determined based on the network-wide synchronization time accumulator counter, and the partial discharge detection time and the partial discharge location event are sent to each of the second acquisition units.

[0014] The first acquisition unit obtains multiple first discharge waveform values ​​corresponding to the partial discharge detection time from the local memory, generates a first discharge pulse frame based on each first discharge waveform value, and uploads the first discharge pulse frame to the measurement host.

[0015] In response to a partial discharge location event, the second acquisition unit retrieves multiple second discharge waveform values ​​corresponding to the partial discharge detection time from its local memory, generates a second discharge pulse frame based on each second discharge waveform value, and uploads the second discharge pulse frame to the measurement host.

[0016] In one embodiment, multiple first discharge waveform values ​​corresponding to the partial discharge detection time are obtained from the local memory, including:

[0017] Query the first write address corresponding to the partial discharge detection time from the memory of the first acquisition unit;

[0018] The first write address segment is determined based on the first write address and the preset first signal quantity;

[0019] Retrieve multiple first discharge waveform values ​​from the first write address segment;

[0020] Retrieve multiple second discharge waveform values ​​corresponding to the partial discharge detection time from the local memory, including:

[0021] The second write address corresponding to the partial discharge detection time is retrieved from the memory of the second acquisition unit.

[0022] The second write address segment is determined based on the second write address and the preset number of second signals;

[0023] Read multiple second discharge waveform values ​​from the second write address segment.

[0024] In one embodiment, the partial discharge dual-end positioning system further includes a communication unit, which is cascaded with each acquisition unit via a data transmission line.

[0025] Before determining the partial discharge detection time corresponding to the partial discharge signal based on the network-wide synchronization time accumulator counter, the method also includes:

[0026] Each front-end unit sends test data to its corresponding back-end unit. The front-end unit includes a communication unit and at least one of the acquisition units, and the back-end unit includes at least one of the acquisition units.

[0027] By dynamically adjusting the corresponding voltage-controlled crystal oscillator of each subsequent unit based on the number of clock edges of the received test data, the clock frequency and phase of adjacent subsequent units are kept consistent with those of the preceding units.

[0028] Each front-end unit sends a delay measurement frame to its corresponding back-end unit and receives feedback information from its corresponding back-end unit in response to the delay measurement frame. Based on the feedback information, the transmission delay between each front-end unit and its corresponding back-end unit is calculated.

[0029] Starting from the communication unit, network-wide synchronization time frames are sent down to each acquisition unit level by level. Each network-wide synchronization time frame includes the network-wide synchronization timestamp of the preceding unit and the transmission delay duration calculated by the preceding unit. The network-wide synchronization time frame is used to update the network-wide synchronization timestamp of the receiving end. The error between the updated network-wide synchronization timestamps of each acquisition unit is less than the preset error threshold.

[0030] In one embodiment, locating the partial discharge signal from the first discharge pulse frame to obtain the first peak time of the partial discharge signal includes:

[0031] Obtain the first start timestamp of the first discharge pulse frame and the second start timestamp of each second discharge pulse frame;

[0032] Detect the start time difference between the first start timestamp and each second start timestamp;

[0033] If at least one initial time difference is less than the corresponding preset time difference threshold, the partial discharge signal is located from the first discharge pulse frame to obtain the first peak time of the partial discharge signal, wherein the preset time difference threshold is determined based on the communication distance and cable length corresponding to the initial time difference.

[0034] In one embodiment, the partial discharge signal is located from the second discharge pulse frame based on feature information to obtain the second peak time of the partial discharge signal, including:

[0035] Based on the feature information, feature recognition is performed on the second discharge pulse frame;

[0036] If a target signal waveform with a similarity to the feature information higher than a preset similarity threshold is identified from the second discharge pulse frame, the peak time of the target signal waveform is determined as the second peak time of the partial discharge signal.

[0037] Secondly, this application also provides a partial discharge dual-end positioning device, comprising:

[0038] The receiving module is used to receive a first discharge pulse frame sent by the first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event. The partial discharge location event is triggered by the first acquisition unit when it detects a partial discharge signal.

[0039] The first positioning module is used to locate the partial discharge signal from the first discharge pulse frame and obtain the first peak time of the partial discharge signal.

[0040] The second positioning module is used to extract feature information of the partial discharge signal from the first discharge pulse frame, locate the partial discharge signal from the second discharge pulse frame based on the feature information, and obtain the second peak time of the partial discharge signal.

[0041] The determination module is used to determine the location of partial discharge based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

[0042] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0043] The system receives a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event, which is triggered by the first acquisition unit when it detects a partial discharge signal.

[0044] The partial discharge signal is located from the first discharge pulse frame, and the first peak time of the partial discharge signal is obtained.

[0045] Feature information of the partial discharge signal is extracted from the first discharge pulse frame, and the partial discharge signal is located from the second discharge pulse frame based on the feature information to obtain the second peak time of the partial discharge signal.

[0046] The location of partial discharge is determined based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

[0047] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0048] The system receives a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event, which is triggered by the first acquisition unit when it detects a partial discharge signal.

[0049] The partial discharge signal is located from the first discharge pulse frame, and the first peak time of the partial discharge signal is obtained.

[0050] Feature information of the partial discharge signal is extracted from the first discharge pulse frame, and the partial discharge signal is located from the second discharge pulse frame based on the feature information to obtain the second peak time of the partial discharge signal.

[0051] The location of partial discharge is determined based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

[0052] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0053] The system receives a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event, which is triggered by the first acquisition unit when it detects a partial discharge signal.

[0054] The partial discharge signal is located from the first discharge pulse frame, and the first peak time of the partial discharge signal is obtained.

[0055] Feature information of the partial discharge signal is extracted from the first discharge pulse frame, and the partial discharge signal is located from the second discharge pulse frame based on the feature information to obtain the second peak time of the partial discharge signal.

[0056] The location of partial discharge is determined based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

[0057] The aforementioned partial discharge dual-end localization method, apparatus, computer equipment, computer-readable storage medium, and computer program product first receive a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one adjacent second acquisition unit. The first discharge pulse frame includes a partial discharge signal with an amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge localization event, which is triggered by the first acquisition unit upon detecting a partial discharge signal. This achieves single-end triggering of the partial discharge dual-end localization method; that is, as long as any acquisition unit identifies a partial discharge signal, the acquisition of the identified partial discharge signal can proceed. The unit and its adjacent acquisition units upload discharge pulse frames; then, by locating the partial discharge signal from the first discharge pulse frame, the first peak time of the partial discharge signal is obtained, the feature information of the partial discharge signal is extracted from the first discharge pulse frame, and the partial discharge signal is located from the second discharge pulse frame based on the feature information, thus obtaining the second peak time of the partial discharge signal. This enables the capture of the partial discharge signal from the second discharge pulse frame where the signal is weak or the noise is strong, thereby determining the time when the partial discharge signal is acquired by both ends; then, by determining the location of the partial discharge based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time, the dual-end positioning of the partial discharge can be achieved.

[0058] In this way, when the partial discharge signal on the cable itself is weak or there is significant environmental interference, making it impossible to identify the partial discharge signal at one end, the transmission of a discharge pulse frame can be triggered by the end that can identify the partial discharge signal. Feature information is extracted from the first discharge pulse frame with a stronger partial discharge signal, and based on this feature information, the partial discharge signal in the second discharge pulse frame with a weaker partial discharge signal is identified. This scheme achieves dual-end localization of even weaker partial discharge signals, significantly improving the detection reliability in weak signal scenarios and overcoming the technical deficiency of traditional methods that lead to localization failure due to single-end signal loss. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is a structural diagram of a partial discharge dual-end positioning system in one embodiment of this application;

[0061] Figure 2 This is a flowchart illustrating a partial discharge dual-end positioning method in one embodiment of this application;

[0062] Figure 3 This is a flowchart illustrating a partial discharge dual-end positioning method in another embodiment of this application;

[0063] Figure 4 This is a pulse waveform diagram of the master and slave ends in one embodiment of this application;

[0064] Figure 5 This is a structural block diagram of a partial discharge dual-end positioning device in one embodiment of this application;

[0065] Figure 6 This is an internal structural diagram of a computer device in one embodiment of this application. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0067] Partial discharge is a significant indicator of insulation degradation in high-voltage power cables. It refers to the non-penetrating discharge phenomenon that occurs in localized areas of the insulating medium under the influence of an electric field. Although the energy of a single discharge is relatively small, prolonged and continuous partial discharge can gradually erode the insulating material, eventually leading to a decline in insulation performance or even equipment breakdown. Therefore, accurate detection and location of partial discharges are of great significance for assessing the insulation condition of cables and preventing power accidents.

[0068] Traditional partial discharge localization primarily employs a two-end positioning technique. This technique requires data acquisition devices deployed at both ends of the cable to capture partial discharge signals separately. The fault location is then determined by comparing the time difference between the signal propagation times of the captured signals at both ends. While this method can achieve meter-level accuracy, it has significant limitations in its application.

[0069] Traditional dual-end positioning technology requires strong partial discharge signals to be acquired at both ends for location to be determined. However, in traditional dual-end positioning technology, a partial discharge signal is usually only identified when the signal amplitude exceeds a certain threshold. If the signal amplitude threshold is too low, a large amount of noise signal will be misidentified as a partial discharge signal. Therefore, the detection sensitivity of partial discharge positioning is limited by the strength of the noise signal, resulting in low detection sensitivity. When the cable partial discharge signal is weak or there is significant electromagnetic interference at the site, causing the partial discharge signal amplitude to be even lower than the noise signal amplitude, it often happens that the signal can be detected at one end while the other end cannot be identified. In such cases, partial discharge positioning cannot be achieved.

[0070] In one exemplary embodiment, a partial discharge dual-end positioning method is provided. This embodiment illustrates the application of this method to a terminal, wherein the terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, projection devices, etc. Portable wearable devices can be smartwatches, smart bracelets, head-mounted devices, etc. Head-mounted devices can be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. It is understood that this method can also be applied to a server, and can also be applied to a system including a terminal and a server, and implemented through the interaction between the terminal and the server.

[0071] In some feasible implementations, this method is applied to a partial discharge dual-end positioning system. A partial discharge dual-end positioning system can refer to a distributed measurement system for detecting and locating partial discharge in high-voltage power cables. Based on the principle of collaborative detection by multiple acquisition units and time difference calculation, it achieves precise location of the partial discharge site. The partial discharge dual-end positioning system includes at least a measurement host and multiple acquisition units, with data interaction and synchronous control between the acquisition units via a high-speed communication network.

[0072] The measurement host coordinates the work of each acquisition unit, performing signal analysis, feature matching, and positioning calculations. Each acquisition unit is a high-precision signal detection device deployed along the cable line. It acquires raw pulse signals from the cable and monitors for the presence of partial discharge signals within these signals. In some feasible implementations, the acquisition unit may also be equipped with a memory to store the raw pulse signals acquired locally. The acquisition unit can communicate with the measurement host, allowing it to upload at least one of the raw pulse signals acquired locally, along with related information, to the measurement host for signal analysis, feature matching, and positioning calculations.

[0073] In some feasible implementations, the terminal may refer to the measurement host or an external controller that controls the partial discharge dual-end positioning system.

[0074] In some feasible implementations, the partial discharge dual-end positioning system may further include a communication unit. The communication unit serves as a synchronization and data exchange hub for the partial discharge dual-end positioning system, enabling time synchronization between the acquisition units and reliable transmission of measurement data. A low-latency, high-precision synchronization system can be constructed between the communication unit and each acquisition unit using an optical fiber communication network to ensure that the sampling clock deviation of each acquisition unit is less than 100 ns, meeting the accuracy requirements of dual-end positioning.

[0075] In some feasible implementations, the system architecture of the partial discharge dual-end positioning system is as follows: Figure 1 As shown, the partial discharge dual-end positioning system consists of a measurement host, a communication unit, multiple acquisition units, a high-frequency current sensor (HFCT, High-Frequency Current Transformer), and optical fiber.

[0076] Multiple cable joints can be installed on the cable according to actual needs. The high-frequency current sensor is connected to the ground wire of the cable joint grounding box. The high-frequency current sensor corresponds to the acquisition unit. The high-frequency current sensor can collect the high-frequency current signal in the cable. The acquisition unit can acquire the high-frequency current signal collected by the high-frequency current sensor and convert the acquired high-frequency current signal into a raw pulse signal after impedance matching, which is used for partial discharge detection and location.

[0077] The communication unit is cascaded with each acquisition unit via optical fiber. The communication unit is connected to the measurement host via network cable.

[0078] Each acquisition unit can be equipped with two dual-port RAMs (Random Access Memory), which are used to buffer the pulse amplitude and pulse time of the original pulse signal, respectively. The RAM used to store the pulse amplitude can have a storage capacity of 8192*16 bits, and the RAM used to store the pulse time can have a storage capacity of 8192*64 bits. When the two RAMs are buffered simultaneously, the write addresses of the two RAMs are the same.

[0079] Figure 1The lightning bolt marker indicates a partial discharge site located on the cable segment between cable joint #1 and cable joint #2. In this case, the partial discharge signal propagates along the cable to both ends and is captured by acquisition unit 1 and acquisition unit 2 respectively. To avoid false detections, the acquisition units typically set an amplitude threshold higher than the noise signal amplitude and identify pulse signals with amplitudes exceeding this threshold as partial discharge signals. However, the partial discharge signal attenuates during cable transmission. This may cause acquisition units farther from the partial discharge site to capture partial discharge signals with amplitudes lower than the noise signal, i.e., lower than the amplitude threshold, thus failing to identify the partial discharge. Furthermore, traditional techniques only capture partial discharge signals from one end, making it impossible to accurately locate the partial discharge site.

[0080] In this embodiment, as Figure 2 As shown, the method includes the following steps S10-S40. Wherein:

[0081] Step S10: Receive a first discharge pulse frame sent by the first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event, which is triggered by the first acquisition unit when it detects a partial discharge signal.

[0082] The acquisition unit may include a first acquisition unit and a second acquisition unit. The first acquisition unit can refer to an acquisition unit capable of acquiring and detecting partial discharge signals; that is, when the partial discharge signal is transmitted to the first acquisition unit, its signal amplitude has not yet attenuated to below a preset amplitude threshold, and therefore it can be identified. The second acquisition unit can refer to an acquisition unit adjacent to the first acquisition unit. If the first acquisition unit identifies a partial discharge signal, but no other acquisition unit identifies the same signal, and if the transmission direction of the partial discharge signal cannot be determined, then both second acquisition units adjacent to the first acquisition unit can upload a second discharge pulse frame.

[0083] A discharge pulse frame can refer to a data packet encapsulated by the acquisition unit from the detected raw pulse signal and its related data. The discharge pulse frame can contain structured data such as discharge waveform, timestamp, amplitude, etc.

[0084] A partial discharge location event can refer to a signal triggered by an acquisition unit, used to notify adjacent acquisition units to initiate collaborative detection. For example, a partial discharge location event can be a trigger command. After a first acquisition unit detects a partial discharge signal whose amplitude exceeds a preset voltage threshold, it can send a trigger command to two adjacent second acquisition units. The second acquisition units, in response to the trigger command, can retrieve the corresponding original pulse signal from their own memory, generate a second discharge pulse frame, and upload the second discharge pulse frame.

[0085] For example, when the first acquisition unit detects a partial discharge signal with an amplitude exceeding a preset voltage threshold, it can retrieve the corresponding original pulse signal from its own memory and generate a first discharge pulse frame based on the retrieved original pulse signal. Simultaneously, it triggers a partial discharge location event and sends this event to the adjacent second acquisition unit, notifying the adjacent second acquisition unit to initiate detection. The adjacent second acquisition unit, in response to the partial discharge location event, retrieves the corresponding original pulse signal from its own memory and generates a second discharge pulse frame based on the retrieved original pulse signal. After generating the first discharge pulse frame, the first acquisition unit can upload the generated first discharge pulse frame to the terminal. After generating the second discharge pulse frame, the second acquisition unit can upload the generated second discharge pulse frame to the terminal. This active triggering mechanism ensures that even if only one end can identify a partial discharge signal, multiple acquisition units can respond synchronously.

[0086] In some feasible implementations, the method for obtaining the corresponding raw pulse signal from the memory of the device can be as follows: obtaining raw pulse signals within a preset duration range before the current time from the memory of the device; or, obtaining raw pulse signals within a preset duration range centered on the current time from the memory of the device. If the raw pulse signals after the current time have not yet been collected, they can be uploaded in real time during the collection process. For example, assuming the current time is T1 and the preset duration range is 2t, the raw pulse signals collected during the time period from T1-2t to T1 can be obtained from the memory of the device, or the raw pulse signals collected during the time period from T1-t to T1+t can be obtained from the memory of the device.

[0087] Step S20: Locate the partial discharge signal from the first discharge pulse frame to obtain the first peak time of the partial discharge signal.

[0088] The peak moment can refer to the time point when the pulse signal reaches its maximum amplitude.

[0089] As an example, after obtaining the first discharge pulse frame, the partial discharge signal can be parsed from the first discharge pulse frame, and then the peak detection algorithm is used to detect the highest amplitude point of the partial discharge signal and record its corresponding timestamp as the first peak moment. The peak detection algorithm can be a sliding window extreme value search, etc.

[0090] As another example, after obtaining the first discharge pulse frame, the peak detection algorithm can be directly used to detect the highest amplitude point of the first discharge pulse frame, and the pulse waveform corresponding to the highest amplitude point can be determined as the pulse waveform of the partial discharge signal in the first discharge pulse frame. The timestamp corresponding to the highest amplitude point can be recorded as the first peak time. The peak detection algorithm can be a sliding window extreme value search, etc.

[0091] In some feasible implementations, the pulse waveform corresponding to the highest amplitude point can refer to a pulse waveform containing a preset number of data points centered on the highest amplitude point. For example, assuming the highest amplitude point is the Nth data point and the preset number is n, then the pulse waveform corresponding to the highest amplitude point can be composed of the Nnth to N+nth data points.

[0092] Step S30: Extract feature information of partial discharge signal from the first discharge pulse frame, locate partial discharge signal from the second discharge pulse frame based on feature information, and obtain the second peak time of partial discharge signal.

[0093] The feature information can refer to at least one of the time-domain parameters and frequency-domain parameters extracted from the pulse signal. For example, the feature information may include at least one identifiable feature quantity such as pulse rise time, oscillation frequency, and waveform envelope.

[0094] For example, after acquiring the first discharge pulse frame and the second discharge pulse frame, feature extraction can be performed on the pulse waveform of the partial discharge signal in the first discharge pulse frame to obtain feature information. Then, in the second discharge pulse frame, the pulse waveform that best matches the feature information is selected through correlation analysis or pattern matching algorithms, and the pulse waveform is determined as the pulse waveform of the partial discharge signal in the second discharge pulse frame. The peak time of the pulse waveform is determined as the second peak time.

[0095] In this way, even if the amplitude of the pulse waveform in the first discharge pulse frame is small and below the preset voltage threshold, and cannot be directly identified as a partial discharge signal, it can still be identified through feature matching. This enables dual-end localization of lower intensity partial discharge signals and improves the detection sensitivity of dual-end localization of partial discharge.

[0096] Step S40: Determine the location of partial discharge based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

[0097] Among them, cable positioning information can be used to characterize the physical location of the acquisition unit on the cable line. For example, cable positioning information can be the length coordinates of the acquisition unit from the cable starting point.

[0098] For example, based on the first cable positioning information corresponding to the first acquisition unit and the second cable positioning information corresponding to the second acquisition unit, the cable length between the first acquisition unit and the second acquisition unit can be calculated. Based on the first peak time and the second peak time, the time difference between the two peak times can be calculated, and the discharge location can then be calculated using the traveling wave ranging principle. For instance, the partial discharge location = (Lv × Δt) / 2, where L is the cable length between the two units, v is the propagation speed of the partial discharge signal in the cable, and Δt is the time difference between the two peak times.

[0099] In the aforementioned dual-end partial discharge localization method, firstly, a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one adjacent second acquisition unit are received. The first discharge pulse frame includes a partial discharge signal with an amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge localization event. This event is triggered by the first acquisition unit upon detecting a partial discharge signal, thus achieving single-end triggering of the dual-end partial discharge localization method. That is, as long as any acquisition unit identifies a partial discharge signal, the acquisition unit that identified the partial discharge signal and its adjacent acquisition units can transmit and amplify the signal. The system uses electrical pulse frames; then, by locating the partial discharge signal from the first discharge pulse frame, the first peak time of the partial discharge signal is obtained. Feature information of the partial discharge signal is extracted from the first discharge pulse frame, and based on the feature information, the partial discharge signal is located from the second discharge pulse frame, obtaining the second peak time of the partial discharge signal. This enables the capture of the partial discharge signal from the second discharge pulse frame where the signal is weak or the noise is strong, thereby determining the time when the partial discharge signal is acquired by both ends. Furthermore, by determining the location of the partial discharge based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time, the dual-end positioning of the partial discharge can be achieved.

[0100] In this way, when the partial discharge signal on the cable itself is weak or there is significant environmental interference, making it impossible to identify the partial discharge signal at one end, the transmission of a discharge pulse frame can be triggered by the end that can identify the partial discharge signal. Feature information is extracted from the first discharge pulse frame with a stronger partial discharge signal, and based on this feature information, the partial discharge signal in the second discharge pulse frame with a weaker partial discharge signal is identified. This scheme achieves dual-end localization of even weaker partial discharge signals, significantly improving the detection reliability in weak signal scenarios and overcoming the technical deficiency of traditional methods that lead to localization failure due to single-end signal loss.

[0101] In one exemplary embodiment, such as Figure 3 As shown, the method is applied to a partial discharge dual-end positioning system. The partial discharge dual-end positioning system includes a measurement host and multiple acquisition units. Each acquisition unit includes a first acquisition unit and at least one second acquisition unit adjacent to the first acquisition unit. Before receiving the first discharge pulse frame sent by the first acquisition unit, the partial discharge dual-end positioning method further includes steps S02 to S06. Wherein:

[0102] Step S02: When a partial discharge signal with an amplitude exceeding a preset voltage threshold is detected by the first acquisition unit, a partial discharge location event is triggered. The partial discharge detection time corresponding to the partial discharge signal is determined based on the network-wide synchronization time accumulator counter, and the partial discharge detection time and the partial discharge location event are sent to each of the second acquisition units.

[0103] The network-wide synchronization time accumulator counter can refer to a high-precision clock source that continuously accumulates time with nanosecond-level resolution. Each acquisition unit can be equipped with a network-wide synchronization time accumulator counter, and the error between the network-wide synchronization time accumulator counters of each acquisition unit should be less than 10 nanoseconds. In some feasible implementations, the error between the network-wide synchronization time accumulator counters of each acquisition unit can be less than 3 nanoseconds.

[0104] Partial discharge detection time can refer to the precise timestamp latched by the network-wide synchronization time accumulator counter when the detected signal amplitude exceeds a preset voltage threshold.

[0105] For example, when the first acquisition unit detects that the signal amplitude of any pulse signal exceeds the preset voltage threshold, it immediately triggers a partial discharge location event. At this time, the network-wide synchronization time accumulator counter inside the first acquisition unit can latch the current count value and generate an accurate partial discharge detection time. Subsequently, the first acquisition unit broadcasts this partial discharge detection time and partial discharge location event to the second acquisition unit adjacent to the first acquisition unit via a synchronization optical cable or high-speed Ethernet.

[0106] Step S04: The first acquisition unit acquires multiple first discharge waveform values ​​corresponding to the partial discharge detection time from the local memory, generates a first discharge pulse frame based on each first discharge waveform value, and uploads the first discharge pulse frame to the measurement host.

[0107] The first discharge waveform value can refer to the original voltage sampling sequence corresponding to the partial discharge detection time, extracted from the memory on the first acquisition unit.

[0108] For example, when the first acquisition unit detects a partial discharge signal whose amplitude exceeds a preset voltage threshold, it extracts multiple first discharge waveform values ​​corresponding to the partial discharge detection time from its local memory. For instance, assuming the partial discharge detection time is T1, multiple sampling points within the range of T1-200ns to T1+200ns can be extracted. Furthermore, the first acquisition unit can generate a first discharge pulse frame based on these first discharge waveform values ​​and their corresponding partial discharge detection times, and upload it to the measurement host via optical fiber.

[0109] Among them, the multiple first discharge waveform values ​​corresponding to the partial discharge detection time can refer to the range of the first discharge waveform values ​​determined with the partial discharge detection time as the center value and the preset time range or preset data volume as the limit.

[0110] Step S06: In response to the partial discharge location event, the second acquisition unit obtains multiple second discharge waveform values ​​corresponding to the partial discharge detection time from the local memory, generates a second discharge pulse frame based on each second discharge waveform value, and uploads the second discharge pulse frame to the measurement host.

[0111] The second discharge waveform value can refer to the original voltage sampling sequence corresponding to the partial discharge detection time, extracted from the memory on the second acquisition unit.

[0112] For example, upon receiving the partial discharge location time and the partial discharge detection time, the second acquisition unit can immediately retrieve multiple second discharge waveform values ​​corresponding to the partial discharge detection time from its local memory. For instance, assuming the partial discharge detection time is T1, multiple sampling points within the range of T1-200ns to T1+200ns can be extracted. Furthermore, the second acquisition unit can generate a second discharge pulse frame based on these second discharge waveform values ​​and their corresponding partial discharge detection times, and upload it to the measurement host via optical fiber.

[0113] Among them, the multiple second discharge waveform values ​​corresponding to the partial discharge detection time can refer to the range of the second discharge waveform values ​​determined by taking the partial discharge detection time as the center value and limiting the range of the second discharge waveform values ​​by a preset time range or a preset data volume.

[0114] In this embodiment, the partial discharge signal can be quickly identified by threshold detection of the first acquisition unit, immediately waking up the adjacent second acquisition unit. This enables the partial discharge dual-end positioning system to capture weak signals that may be missed by traditional methods. Simultaneously, timestamp alignment using a network-wide synchronization time accumulator counter ensures strict synchronization of signals from multiple ends, eliminating positioning errors caused by cable transmission delays.

[0115] In an exemplary embodiment, multiple first discharge waveform values ​​corresponding to the partial discharge detection time are obtained from the local memory, including:

[0116] The first write address corresponding to the partial discharge detection time is retrieved from the memory of the first acquisition unit; the first write address segment is determined based on the first write address and the preset number of first signals; and multiple first discharge waveform values ​​are retrieved from the first write address segment.

[0117] The first write address can refer to the write location of the data written to the memory of the first acquisition unit at the partial discharge detection time.

[0118] The preset first signal quantity can refer to the number of pulse waveform data to be extracted, which can be determined in advance based on signal characteristics and actual conditions. This embodiment does not impose any restrictions on this.

[0119] The first write address segment can refer to a contiguous memory region containing a preset number of sample points corresponding to the first write address. The first write address segment includes the first write address, which can be located at the end or in the middle of the first write address segment. The specific location can be determined according to the actual situation, and this embodiment does not impose any restrictions on this.

[0120] For example, after determining the partial discharge detection time, the first acquisition unit can immediately obtain the first write address corresponding to the partial discharge detection time from the write address pointer register of the local memory; then, based on the preset first signal quantity, the first write address segment can be calculated with the first write address as the endpoint or midpoint; then, multiple first discharge waveform values ​​can be read sequentially from the memory area corresponding to the first write address segment.

[0121] Retrieve multiple second discharge waveform values ​​corresponding to the partial discharge detection time from the local memory, including:

[0122] The second write address corresponding to the partial discharge detection time is retrieved from the memory of the second acquisition unit; the second write address segment is determined based on the second write address and the preset number of second signals; and multiple second discharge waveform values ​​in the second write address segment are read.

[0123] The first write address can refer to the write location of the data written to the memory of the first acquisition unit at the partial discharge detection time.

[0124] The preset second signal quantity can refer to the number of pulse waveform data to be extracted, which can be determined in advance based on signal characteristics and actual conditions. This embodiment does not impose any restrictions on this.

[0125] The second write address segment can refer to a continuous memory region containing a preset number of sampling points of the second signal corresponding to the second write address. The second write address segment includes the second write address, which can be located at the end or in the middle of the second write address segment. The specific location can be determined according to the actual situation, and this embodiment does not impose any restrictions on this.

[0126] For example, after determining the partial discharge detection time, the second acquisition unit can immediately obtain the second write address corresponding to the partial discharge detection time from the write address pointer register of the local memory; then, based on the preset number of second signals, the second write address segment can be calculated with the second write address as the endpoint or midpoint; then, multiple second discharge waveform values ​​can be read sequentially from the memory area corresponding to the second write address segment.

[0127] In this embodiment, when the first acquisition unit detects a discharge signal, it can immediately lock the first write address of the memory through a timestamp, and intelligently backtrack the corresponding first write address segment based on a preset first signal quantity, thereby completely extracting the original pulse signal containing the partial discharge signal.

[0128] In an exemplary embodiment, the partial discharge dual-end positioning system further includes a communication unit, which is cascaded with each acquisition unit via a data transmission line; before determining the partial discharge detection time corresponding to the partial discharge signal based on the network-wide synchronization time accumulator counter, the partial discharge dual-end positioning method further includes:

[0129] Step S011: Each front-end unit sends test data to its corresponding back-end unit. The front-end unit includes at least one of a communication unit and a data acquisition unit, and the back-end unit includes at least one of a data acquisition unit.

[0130] In this system, the communication unit and each acquisition unit are connected in series via data transmission lines, forming a continuous data transmission link. These data transmission lines can be fiber optic cables or high-speed Ethernet cables. For example, the communication unit can act as the master node, connecting to the first acquisition unit. This acquisition unit then connects to the second acquisition unit via a downlink interface, and so on, extending in series to the last acquisition unit. Synchronization commands and trigger signals can be transmitted from top to bottom, from the communication unit to the acquisition unit, while the acquired data can be aggregated from bottom to top, from the acquisition unit to the communication unit. This cascaded design perfectly suits the linear distribution of power cables, providing a cost-effective solution for long-distance partial discharge dual-end positioning systems, with its value particularly prominent in narrow environments such as tunnels and utility tunnels.

[0131] The concepts of front-end unit and back-end unit are relative. For any communication unit or acquisition unit, the communication unit or acquisition unit at the next higher level is its front-end unit, and the acquisition unit at the next lower level is its back-end unit.

[0132] Test data can refer to periodic square wave signals used for clock calibration.

[0133] For example, network-wide time synchronization can be performed periodically before or during partial discharge monitoring. Specifically, test data can be sent to the subsequent acquisition unit via the communication unit. The test data is transmitted serially on the data transmission line, and can be 8B10B encoded before transmission to ensure sufficient clock edge information in the data.

[0134] Step S012: Each subsequent unit dynamically adjusts its corresponding voltage-controlled crystal oscillator based on the number of clock edges of the received test data, so that the clock frequency and phase of adjacent subsequent units are consistent with those of the preceding units.

[0135] The clock edge count refers to the number of rising or falling edges of a signal detected per unit of time.

[0136] Voltage-controlled crystal oscillators (VCOs) refer to crystal oscillators whose output frequency can be adjusted by voltage.

[0137] For example, after the test data enters the subsequent unit, it can first pass through a serial processing channel composed of an even number of fixed delay units. The delay time of each stage is precisely set to an equal division of the voltage-controlled crystal oscillator period. In each clock cycle, the system detects the output signals of all delay stages in parallel to accurately determine the specific position of the clock edge in the delay chain. When the edge appears in the first half of the delay stage, the edge counter automatically increments, and when it appears in the second half, it decrements. When the counter reaches its extreme value, it is reset to the intermediate value and the crystal oscillator adjustment signal is output. Through this closed-loop control mechanism, the voltage-controlled crystal oscillator is continuously and dynamically adjusted, so that the clock edge is stably locked at the center position of the delay chain, thereby ensuring that the subsequent unit and the preceding unit maintain strict frequency and phase synchronization, with a synchronization accuracy of up to the nanosecond level.

[0138] Step S013: Each front-end unit sends a delay measurement frame to its corresponding back-end unit and receives feedback information from its corresponding back-end unit in response to the delay measurement frame. Based on the feedback information, the transmission delay between each front-end unit and its corresponding back-end unit is calculated.

[0139] Among them, the delay measurement frame can refer to the marked data packet used to measure the link transmission delay.

[0140] For example, when the clock frequencies and phases of adjacent units are consistent, the communication unit can send a delay measurement frame to the subsequent acquisition unit. The delay measurement frame is transmitted serially on the data transmission line. The front-end unit sends the delay measurement frame and records the sending time. After receiving the delay measurement frame, the subsequent unit records the receiving time and, when the timer reaches a preset waiting time, returns feedback information to the front-end unit. The feedback information includes the receiving time and the preset waiting time. The front-end unit can then calculate the one-way transmission delay based on the received receiving time, the preset waiting time, and the sending time.

[0141] In some feasible implementations, step S013 can be repeated multiple times until the measurement results are consistent or the error is less than the preset error, and the accurate transmission delay duration is stored in the front-end unit.

[0142] Step S014: Starting from the communication unit, the network synchronization time frame is sent down to each acquisition unit level by level. Each network synchronization time frame includes the network synchronization timestamp of the preceding unit and the transmission delay duration calculated by the preceding unit. The network synchronization time frame is used to update the network synchronization timestamp of the receiving end. The error between the updated network synchronization timestamps of each acquisition unit is less than the preset error threshold.

[0143] Among them, the network-wide synchronized timestamp can refer to the absolute time reference based on the master clock of the communication unit.

[0144] A network-wide synchronization time frame can refer to a data packet that carries a network-wide synchronization timestamp and transmission delay duration.

[0145] For example, after determining the transmission delay duration, a network-wide synchronization time frame can be sent sequentially downwards from the communication unit. After receiving the network-wide synchronization time frame, each subsequent unit can extract the network-wide synchronization timestamp and transmission delay duration of the preceding unit from the network-wide synchronization time frame. Then, it can add the transmission delay duration to the network-wide synchronization timestamp of the preceding unit, update the network-wide synchronization timestamp, append the transmission delay duration from the current level to the next level, and continue to send the updated network-wide synchronization time frame.

[0146] In this embodiment, by dynamically controlling the voltage-controlled crystal oscillator, the clocks of all serially connected acquisition units can have the same frequency and phase; by operating the delay frame, the transmission delay value between adjacent units can be obtained; by processing the whole network synchronization time frame, each acquisition unit will obtain the same whole network synchronization time, and the system achieves high-precision time synchronization, thereby effectively improving the partial discharge measurement effect and the partial discharge positioning accuracy.

[0147] In an exemplary embodiment, locating the partial discharge signal from the first discharge pulse frame to obtain the first peak time of the partial discharge signal includes steps S21 to S23. Wherein:

[0148] Step S212: Obtain the first start timestamp of the first discharge pulse frame and the second start timestamp of each second discharge pulse frame.

[0149] The first start timestamp can refer to the timestamp corresponding to the first pulse waveform in the first discharge pulse frame. The second start timestamp can refer to the timestamp corresponding to the first pulse waveform in the second discharge pulse frame.

[0150] For example, after acquiring the first discharge pulse frame, the pulse waveform can be identified starting from the earliest time of the first discharge pulse frame, and the timestamp corresponding to the first identified pulse waveform can be determined as the first start timestamp of the first discharge pulse frame; after acquiring the second discharge pulse frame, the pulse waveform can be identified starting from the earliest time of the second discharge pulse frame, and the timestamp corresponding to the second identified pulse waveform can be determined as the second start timestamp of the second discharge pulse frame.

[0151] Step S22: Detect the start time difference between the first start timestamp and each second start timestamp.

[0152] The start time difference can refer to the absolute time difference between the start timestamps of two discharge pulse frames.

[0153] For example, after determining the first start timestamp and the second start timestamp, the start time difference between the first start timestamp and each of the second start timestamps can be calculated.

[0154] Step S23: When at least one starting time difference is less than the corresponding preset time difference threshold, locate the partial discharge signal from the first discharge pulse frame and obtain the first peak time of the partial discharge signal, wherein the preset time difference threshold is determined based on the communication distance and cable length corresponding to the starting time difference.

[0155] The preset time difference threshold can refer to the maximum allowable time difference calculated based on the communication distance and cable length.

[0156] For example, if any initial time difference is less than a preset time difference threshold, the target second discharge pulse frame and the target second acquisition unit corresponding to the initial time difference less than the preset time difference threshold can be further determined. It can be determined that the target second discharge pulse frame and the first discharge pulse frame come from the same discharge event, that is, it can be determined that the target second discharge pulse frame should contain a partial discharge signal. In this case, the partial discharge signal can be located from the first discharge pulse frame to obtain the first peak time of the partial discharge signal.

[0157] If the initial time difference is greater than the preset time difference threshold, it can be determined that the second discharge pulse frame and the first discharge pulse frame do not originate from the same discharge event. The second discharge pulse frame is likely not to contain a partial discharge signal. To avoid subsequent invalid detection processes, the currently acquired first and second discharge pulse frames can be discarded, and the process can return to receiving the first discharge pulse frame sent by the first acquisition unit, and the second discharge pulse frame sent by at least one adjacent second acquisition unit. In the presence of partial discharge, the partial discharge signal will continue to be generated and continuously acquired by the acquisition unit.

[0158] In this embodiment, the accuracy and real-time performance of discharge signal correlation can be effectively improved by combining timestamp comparison and threshold judgment. Peak detection is only initiated when the time difference meets the requirements, avoiding noise-induced false triggering and saving computing resources.

[0159] In an exemplary embodiment, the partial discharge signal is located from the second discharge pulse frame based on feature information to obtain the second peak time of the partial discharge signal, including steps S31 to S32. Wherein:

[0160] Step S31: Based on the feature information, perform feature recognition on the second discharge pulse frame.

[0161] For example, after extracting the feature information of the partial discharge signal, feature recognition can be performed on the second discharge pulse frame based on the feature information to determine whether the second discharge pulse frame contains a partial discharge signal. The specific method of feature recognition is similar to the prior art, and will not be described in detail here.

[0162] In some feasible implementations, the method for feature recognition of the second discharge pulse frame based on the feature information can be as follows: the data volume of the second discharge pulse frame is determined as the window length, starting from the second start timestamp of the second discharge pulse frame, the first window data is extracted, and the first window data is compared with the feature information; if the similarity between the two is higher than a preset similarity threshold, it can be considered that the pulse waveform corresponding to the first window data is the pulse waveform corresponding to the partial discharge signal, and the feature recognition ends; if the similarity between the two is not higher than the preset similarity threshold, it can be considered that the pulse waveform corresponding to the first window data is not the pulse waveform corresponding to the partial discharge signal, and the window can be slid based on a preset sliding step size, the next window data is extracted, and the next window data is compared with the feature information, and so on, the window data is updated until a pulse waveform with a similarity higher than the preset similarity threshold is detected, or the sliding window reaches the end timestamp of the second discharge pulse frame.

[0163] If no pulse waveform with a similarity higher than a preset similarity threshold is detected until the sliding window reaches the end timestamp of the second discharge pulse frame, it can be determined that the second discharge pulse frame does not contain a pulse waveform corresponding to a partial discharge signal. The partial discharge signal may exist on the other side of the first acquisition unit.

[0164] Based on the feature information extracted from the first discharge pulse frame (such as a rising edge of 3ns and an oscillation frequency of 12MHz), segment-by-segment feature identification is performed on the second discharge pulse frame. Using a time-frequency joint analysis algorithm (such as Dynamic Time Warping (DTW) or wavelet correlation coefficient), the similarity score between each candidate waveform segment and the feature template in the second frame is calculated. When the similarity of a waveform segment exceeds a preset similarity threshold (such as 0.85), it is marked as the target signal waveform, and interpolation is used to accurately locate the time corresponding to its peak point (e.g., identifying the peak at timestamp T2+18ns). Finally, this time is determined as the second peak time.

[0165] Step S32: If a target signal waveform with a similarity higher than a preset similarity threshold is identified from the second discharge pulse frame, the peak time of the target signal waveform is determined as the second peak time of the partial discharge signal.

[0166] The similarity threshold can refer to the lowest similarity score used to determine the correlation between waveforms. If the similarity between two waveforms is higher than the similarity threshold, it can be considered that the two waveforms are formed by the same discharge source. The specific value can be determined based on experience or test results, etc. This embodiment does not impose any restrictions on this.

[0167] For example, when the similarity between a waveform and feature information exceeds a preset similarity threshold, it can be marked as a target signal waveform, and the peak time corresponding to the peak point of the target signal waveform can be accurately located, and the peak time can be determined as the second peak time of the partial discharge signal.

[0168] In this embodiment, by replacing the traditional amplitude triggering with feature matching, the weak signal recognition rate can be significantly improved, thereby increasing the sensitivity of partial discharge dual-end localization.

[0169] In some feasible implementations, the partial discharge dual-end positioning method is applied to a partial discharge dual-end positioning system, which consists of a measurement host, a communication unit, several partial discharge acquisition units, several high-frequency current sensors, and optical fibers. Cable joints are installed at intervals along the cable, with each cable joint, high-frequency current sensor, and acquisition unit corresponding to a specific unit. The high-frequency current sensor is connected to the ground wire of the grounding box at each cable joint and transmits the acquired data to the corresponding acquisition unit. The communication unit and the acquisition units achieve network-wide synchronization via optical fibers. Each acquisition unit has a 64-bit network-wide synchronization time accumulator counter, and the error between the network-wide synchronization time accumulator counters of each acquisition unit is less than 3. Each acquisition unit has two dual-port RAMs to buffer the pulse amplitude and pulse time, respectively an 8192*16-bit pd_wave_ram and an 8192*64-bit pd_time_ram. Because the two RAMs are buffered simultaneously, their write addresses are the same.

[0170] For ease of understanding, the end where partial discharge is detected is called the master end, and the end where partial discharge is not detected is called the slave end.

[0171] Partial discharge two-end localization methods include:

[0172] The master terminal identifies the partial discharge signal based on the voltage threshold and records the write address at the moment the partial discharge signal is identified, denoted as pd_time_ram_trig_wr_addr1. Simultaneously, it records the write data at the moment the partial discharge signal is identified, denoted as pd_time_ram_trig_time1.

[0173] The master terminal reads pulse amplitude values ​​from pd_wave_ram, centered on pd_time_ram_trig_wr_addr1, corresponding to address ranges greater than pd_time_ram_trig_wr_addr1-1024 and less than pd_time_ram_trig_wr_addr1+1024, forming a discharge waveform value containing 2048 data points. It also reads pulse timestamps from pd_time_ram, corresponding to address ranges greater than pd_time_ram_trig_wr_addr1-1024 and less than pd_time_ram_trig_wr_addr1+1024, obtaining timestamps corresponding to the 2048 data points of the discharge waveform value. The first timestamp read from pd_time_ram is marked as the start time (start_tim1) of the master terminal's discharge pulse, and this timetamp, along with the 2048 discharge waveform values ​​read from pd_wave_ram, forms a discharge pulse frame. The master terminal then uploads the generated discharge pulse frame to the measurement host.

[0174] The master transmits pd_time_ram_trig_time1 to the slave via optical fiber. The slave reads the entire pd_time_ram and finds the write address corresponding to the value of pd_time_ram_trig_time1, which is denoted as pd_time_ram_trig_wr_addr2.

[0175] Centered on pd_time_ram_trig_wr_addr2, the slave device reads pulse amplitude values ​​corresponding to address segments greater than pd_time_ram_trig_wr_addr2-1024 and less than pd_time_ram_trig_wr_addr2+1024 from pd_wave_ram, forming a discharge waveform value containing 2048 data points. It also reads pulse times corresponding to address segments greater than pd_time_ram_trig_wr_addr2-1024 and less than pd_time_ram_trig_wr_addr2+1024 from pd_time_ram, obtaining timestamps corresponding to the 2048 data points of the discharge waveform value. The first timestamp read from pd_time_ram is marked as the start time start_tim2 of the slave device's discharge pulse, and this timetamp, along with the 2048 discharge waveform values ​​read from pd_wave_ram, forms a discharge pulse frame. Finally, the slave device uploads the generated discharge pulse frame to the measurement host.

[0176] The measurement host first analyzes the discharge pulse frame uploaded by the master end, finds the peak position of the partial discharge signal, and records it as p1. The peak timestamp of the partial discharge signal on the master end is marked as T1=pd_time_trig_start_time1+p1.

[0177] The measurement host takes 32 points to the left and right of the peak position of the partial discharge signal to form a 64-point partial discharge signal, and extracts the characteristic parameters.

[0178] Then, the measurement host analyzes the discharge pulse frames uploaded from the slave end. Following a sliding step size of 4 data points and a sliding window length of 64 data points, window data is extracted from the uploaded discharge pulse frames. Feature information is extracted from the extracted window data, and correlation calculation is performed with the feature information extracted from the master end. The window data with the strongest correlation to the feature information extracted from the master end is found, and its peak position is recorded as p2. Finally, the peak timestamp of the slave end partial discharge signal is marked as T2 = pd_time_trig_start_time2 + p2. The pulse waveforms at both the master and slave ends are shown below. Figure 4 As shown, Figure 4 The upper middle section shows the pulse waveform corresponding to the discharge pulse frame uploaded by the main terminal. Figure 4 The lower center shows the pulse waveform corresponding to the discharge pulse frame uploaded from the slave end.

[0179] The measuring host calculates the absolute value of the time difference between the peak values ​​of the partial discharge signals at the master and slave ends, which is equal to (T1-T2), denoted as ΔT. Given the distance L between the master and slave cables and the propagation speed V of the partial discharge signal in the cable, the distance of the partial discharge signal from the master end can be calculated to be (L-ΔT*V) / 2, thereby realizing the location of partial discharge faults in the power cable itself.

[0180] The high-frequency current sensor is connected to the grounding wire of the grounding box near the cable joint. The partial discharge signal detected by the sensor is not always a strong partial discharge signal; often, only one end can detect a partial discharge signal, such as when the cable body is ablated. In this case, it is generally difficult to locate the partial discharge fault in the cable body using conventional dual-end positioning techniques. However, if the dual-end positioning method of this embodiment is used, it can efficiently locate the weak partial discharge in the cable body, especially the partial discharge caused by cable body ablation, thereby effectively avoiding cable faults caused by cable body ablation.

[0181] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0182] Based on the same inventive concept, this application also provides a partial discharge double-end positioning device for implementing the above-mentioned partial discharge double-end positioning method. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more partial discharge double-end positioning device embodiments provided below can be found in the limitations of the partial discharge double-end positioning method above, and will not be repeated here.

[0183] In one exemplary embodiment, such as Figure 5 As shown, a partial discharge dual-end positioning device is provided, comprising: a receiving module 502, a first positioning module 504, a second positioning module 506, and a determining module 508, wherein:

[0184] The receiving module 502 is used to receive a first discharge pulse frame sent by the first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event. The partial discharge location event is triggered by the first acquisition unit when it detects a partial discharge signal.

[0185] The first positioning module 504 is used to locate the partial discharge signal from the first discharge pulse frame and obtain the first peak time of the partial discharge signal.

[0186] The second positioning module 506 is used to extract feature information of the partial discharge signal from the first discharge pulse frame, locate the partial discharge signal from the second discharge pulse frame based on the feature information, and obtain the second peak time of the partial discharge signal.

[0187] The determination module 508 is used to determine the location of partial discharge based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

[0188] In an exemplary embodiment, the device is applied to a partial discharge dual-end positioning system, which includes a measurement host and multiple acquisition units. Each acquisition unit includes a first acquisition unit and at least one second acquisition unit adjacent to the first acquisition unit. The device further includes an acquisition module. Before receiving a first discharge pulse frame sent by the first acquisition unit, the acquisition module is further configured to:

[0189] When a partial discharge signal with an amplitude exceeding a preset voltage threshold is detected by the first acquisition unit, a partial discharge location event is triggered. The partial discharge detection time corresponding to the partial discharge signal is determined based on the network-wide synchronization time accumulator counter, and the partial discharge detection time and the partial discharge location event are sent to each of the second acquisition units.

[0190] The first acquisition unit obtains multiple first discharge waveform values ​​corresponding to the partial discharge detection time from the local memory, generates a first discharge pulse frame based on each first discharge waveform value, and uploads the first discharge pulse frame to the measurement host.

[0191] In response to a partial discharge location event, the second acquisition unit retrieves multiple second discharge waveform values ​​corresponding to the partial discharge detection time from its local memory, generates a second discharge pulse frame based on each second discharge waveform value, and uploads the second discharge pulse frame to the measurement host.

[0192] In one exemplary embodiment, the acquisition module is further configured to:

[0193] Query the first write address corresponding to the partial discharge detection time from the memory of the first acquisition unit;

[0194] The first write address segment is determined based on the first write address and the preset first signal quantity;

[0195] Retrieve multiple first discharge waveform values ​​from the first write address segment;

[0196] The second write address corresponding to the partial discharge detection time is retrieved from the memory of the second acquisition unit.

[0197] The second write address segment is determined based on the second write address and the preset number of second signals;

[0198] Read multiple second discharge waveform values ​​from the second write address segment.

[0199] In an exemplary embodiment, the partial discharge dual-end positioning system further includes a communication unit, which is cascaded with each acquisition unit via a data transmission line; before determining the partial discharge detection time corresponding to the partial discharge signal based on the network-wide synchronization time accumulator counter, the acquisition module is also used for:

[0200] Each front-end unit sends test data to its corresponding back-end unit. The front-end unit includes a communication unit and at least one of the acquisition units, and the back-end unit includes at least one of the acquisition units.

[0201] By dynamically adjusting the corresponding voltage-controlled crystal oscillator of each subsequent unit based on the number of clock edges of the received test data, the clock frequency and phase of adjacent subsequent units are kept consistent with those of the preceding units.

[0202] Each front-end unit sends a delay measurement frame to its corresponding back-end unit and receives feedback information from its corresponding back-end unit in response to the delay measurement frame. Based on the feedback information, the transmission delay between each front-end unit and its corresponding back-end unit is calculated.

[0203] Starting from the communication unit, network-wide synchronization time frames are sent down to each acquisition unit level by level. Each network-wide synchronization time frame includes the network-wide synchronization timestamp of the preceding unit and the transmission delay duration calculated by the preceding unit. The network-wide synchronization time frame is used to update the network-wide synchronization timestamp of the receiving end. The error between the updated network-wide synchronization timestamps of each acquisition unit is less than the preset error threshold.

[0204] In an exemplary embodiment, the first positioning module 504 is further configured to:

[0205] Obtain the first start timestamp of the first discharge pulse frame and the second start timestamp of each second discharge pulse frame;

[0206] Detect the start time difference between the first start timestamp and each second start timestamp;

[0207] If at least one initial time difference is less than the corresponding preset time difference threshold, the partial discharge signal is located from the first discharge pulse frame to obtain the first peak time of the partial discharge signal, wherein the preset time difference threshold is determined based on the communication distance and cable length corresponding to the initial time difference.

[0208] In one exemplary embodiment, the second positioning module 506 is further configured to:

[0209] Based on the feature information, feature recognition is performed on the second discharge pulse frame;

[0210] If a target signal waveform with a similarity to the feature information higher than a preset similarity threshold is identified from the second discharge pulse frame, the peak time of the target signal waveform is determined as the second peak time of the partial discharge signal.

[0211] Each module in the aforementioned partial discharge dual-end positioning device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0212] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When executed by the processor, the computer program implements a partial discharge dual-end positioning method. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0213] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0214] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0215] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0216] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0217] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0218] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0219] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0220] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A partial discharge two-terminal locating method, characterized in that, The method includes: The system receives a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event, which is triggered by the first acquisition unit when it detects the partial discharge signal. The partial discharge signal is located from the first discharge pulse frame to obtain the first peak time of the partial discharge signal; The feature information of the partial discharge signal is extracted from the first discharge pulse frame, and the partial discharge signal is located from the second discharge pulse frame based on the feature information to obtain the second peak time of the partial discharge signal; The location of partial discharge is determined based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

2. The method of claim 1, wherein, The method is applied to a partial discharge dual-end positioning system, which includes a measurement host and multiple acquisition units. Each acquisition unit includes a first acquisition unit and at least one second acquisition unit adjacent to the first acquisition unit. Before receiving the first discharge pulse frame sent by the first acquisition unit, the method further includes: When a partial discharge signal with an amplitude exceeding a preset voltage threshold is detected by the first acquisition unit, a partial discharge location event is triggered. The partial discharge detection time corresponding to the partial discharge signal is determined based on the network-wide synchronization time accumulator counter, and the partial discharge detection time and the partial discharge location event are sent to each of the second acquisition units. The first acquisition unit obtains multiple first discharge waveform values ​​corresponding to the partial discharge detection time from the local memory, generates a first discharge pulse frame based on each first discharge waveform value, and uploads the first discharge pulse frame to the measurement host. In response to the partial discharge location event, the second acquisition unit retrieves multiple second discharge waveform values ​​corresponding to the partial discharge detection time from its local memory, generates a second discharge pulse frame based on each second discharge waveform value, and uploads the second discharge pulse frame to the measurement host.

3. The method of claim 2, wherein, The step of retrieving multiple first discharge waveform values ​​corresponding to the partial discharge detection time from the local memory includes: Query the first write address corresponding to the partial discharge detection time from the memory of the first acquisition unit; The first write address segment is determined based on the first write address and the preset first signal quantity; Take multiple first discharge waveform values ​​from the first write address segment; The step of retrieving multiple second discharge waveform values ​​corresponding to the partial discharge detection time from the local memory includes: Query the second write address corresponding to the partial discharge detection time from the memory of the second acquisition unit; The second write address segment is determined based on the second write address and the preset second signal quantity; Read multiple second discharge waveform values ​​from the second write address segment.

4. The method of claim 2, wherein, The partial discharge dual-end positioning system also includes a communication unit, and the communication unit and each of the acquisition units are cascaded through a data transmission line; Before determining the partial discharge detection time corresponding to the partial discharge signal based on the network-wide synchronization time accumulator counter, the method further includes: Each front-end unit sends test data to its corresponding back-end unit. The front-end unit includes at least one of the communication unit and each of the acquisition units, and the back-end unit includes at least one of the acquisition units. By dynamically adjusting the corresponding voltage-controlled crystal oscillator of each subsequent unit based on the number of clock edges of the received test data, the clock frequency and phase of adjacent subsequent units are kept consistent with those of the preceding units. Each front-end unit sends a delay measurement frame to its corresponding back-end unit and receives feedback information from its corresponding back-end unit in response to the delay measurement frame. Based on the feedback information, the transmission delay duration between each front-end unit and its corresponding back-end unit is calculated. Starting from the communication unit, a network-wide synchronization time frame is sent down to each of the acquisition units level by level. Each network-wide synchronization time frame includes the network-wide synchronization timestamp of the preceding unit and the transmission delay duration calculated by the preceding unit. The network-wide synchronization time frame is used to update the network-wide synchronization timestamp of the receiving end. The error between the updated network-wide synchronization timestamps of each acquisition unit is less than a preset error threshold.

5. The method according to any one of claims 1 to 4, characterized in that, The step of locating the partial discharge signal from the first discharge pulse frame and obtaining the first peak time of the partial discharge signal includes: Obtain the first start timestamp of the first discharge pulse frame and the second start timestamp of each of the second discharge pulse frames; Detect the start time difference between the first start timestamp and each of the second start timestamps; If at least one of the initial time differences is less than the corresponding preset time difference threshold, the partial discharge signal is located from the first discharge pulse frame to obtain the first peak time of the partial discharge signal, wherein the preset time difference threshold is determined based on the communication distance and cable length corresponding to the initial time difference.

6. The method according to any one of claims 1 to 4, characterized in that, The step of locating the partial discharge signal from the second discharge pulse frame based on the feature information and obtaining the second peak time of the partial discharge signal includes: Based on the aforementioned feature information, feature recognition is performed on the second discharge pulse frame; If a target signal waveform with a similarity to the feature information higher than a preset similarity threshold is identified from the second discharge pulse frame, the peak time of the target signal waveform is determined as the second peak time of the partial discharge signal.

7. A partial discharge two-terminal positioning device, characterized by The device includes: The receiving module is configured to receive a first discharge pulse frame sent by a first acquisition unit and a second discharge pulse frame sent by at least one second acquisition unit adjacent to the first acquisition unit. The first discharge pulse frame includes a partial discharge signal with a signal amplitude exceeding a preset voltage threshold. The second discharge pulse frame is generated by the second acquisition unit in response to a partial discharge location event, which is triggered by the first acquisition unit when it detects the partial discharge signal. The first positioning module is used to locate the partial discharge signal from the first discharge pulse frame and obtain the first peak time of the partial discharge signal. The second positioning module is used to extract feature information of the partial discharge signal from the first discharge pulse frame, locate the partial discharge signal from the second discharge pulse frame based on the feature information, and obtain the second peak time of the partial discharge signal. The determination module is used to determine the location of partial discharge based on the first cable positioning information corresponding to the first acquisition unit, the second cable positioning information corresponding to the second acquisition unit, the first peak time, and the second peak time.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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