Ultra-narrow partial discharge pulse transient detection system and method based on double-path overlapping acquisition

Abstract

The invention discloses an ultra-narrow partial discharge pulse transient detection system and method based on double-path overlapping acquisition, and relates to the technical field of high-frequency weak signal detection.According to the ultra-narrow partial discharge pulse transient detection system and method based on double-path overlapping acquisition, an ultra-narrow partial discharge pulse waveform is obtained through signal conversion of an ultrahigh-frequency sensor, cooperative overlapping acquisition of double-path acquisition modules and processing of a fusion module, traditional limitation is broken through, and the detection accuracy is improved. Accurate capture and feature extraction are achieved, data are provided for partial discharge analysis, the detection and diagnosis accuracy is improved, single-path shortages are made up by means of double-path collection, and comprehensiveness is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-frequency weak signal detection, and in particular to an ultra-narrow partial discharge pulse transient detection system and method based on double-path overlapping collection. BACKGROUND

[0002] In the field of power equipment operation and maintenance, partial discharge detection is a key means to ensure the safe operation of equipment. Ultra high frequency (UHF) partial discharge detection is widely used in the state monitoring of high-voltage switch cabinets, GIS and other equipment because it can effectively capture the electromagnetic pulse signals of partial discharge radiation without affecting the operation of the equipment.

[0003] With the development of power equipment towards high voltage, large capacity and intelligentization, partial discharge pulses show an ultra-narrow trend, especially early partial discharge caused by some insulation defects, whose transient pulse width is often less than 5 nanoseconds. Such ultra-narrow partial discharge pulses contain key information of the insulation state of the equipment, but due to the extremely short duration of the pulse and the complex signal characteristics, it puts forward strict requirements on the transient response capability and signal capture integrity of the detection system.

[0004] However, the existing partial discharge detection system has the following defects when facing ultra-narrow transient pulses: on the one hand, the traditional peak holding circuit is limited by the diode reverse recovery time (usually > 10 nanoseconds) and the insufficient slew rate of the operational amplifier, making it difficult to accurately capture ultra-narrow partial discharge pulses with a width of < 5 nanoseconds, which easily leads to pulse signal loss or distortion, and cannot effectively extract key features such as pulse front and back edges, thereby affecting the positioning accuracy of the partial discharge source and the accuracy of the partial discharge type recognition, becoming a key bottleneck restricting the effective detection of ultra-narrow partial discharge pulses and the accurate evaluation of the insulation state of the equipment; on the other hand, the single-path collection mode further exacerbates the pulse loss problem due to the randomness and low repetition rate characteristics of partial discharge pulses, making it difficult to fully meet the signal collection needs in complex partial discharge scenarios. SUMMARY

[0005] In order to solve the technical problems that the existing partial discharge detection system cannot accurately capture ultra-narrow partial discharge pulses, easily loses pulses, and cannot effectively extract key features, the present application provides an ultra-narrow partial discharge pulse transient detection system and method based on double-path overlapping collection.

[0006] The ultra-narrow partial discharge pulse transient detection system based on double-path overlapping collection provided by the present application adopts the following technical solution: An ultra high frequency sensor for converting ultra high frequency electromagnetic pulses of a target region into an initial partial discharge electrical signal; A first collection channel module and a second collection channel module are connected in parallel with the ultra high frequency sensor; The first acquisition channel module and the second acquisition channel module are used for cooperatively performing double-path parallel overlapping acquisition on the initial partial discharge signal to obtain a first differential signal and a second differential signal. The signal fusion module is configured to perform signal fusion on the first differential signal and the second differential signal to obtain an ultra-narrow partial discharge pulse waveform signal.

[0007] By using the above technical solution, the ultra-high frequency sensor is used as a signal acquisition source to accurately capture the ultra-high frequency electromagnetic pulse of the target area and convert it into an initial partial discharge signal, thereby providing a basis for subsequent detection. The double-path parallel and cooperatively overlapping acquisition channel module cooperates with the first acquisition channel to quickly capture the pulse front and the second acquisition channel to finely acquire the pulse tail, and cooperates with the overlapping connection in time sequence to effectively cover the complete period of the ultra-narrow partial discharge pulse from the beginning to the end, thereby avoiding the feature loss problem caused by the randomness and low repetition rate of the pulse in single-path acquisition. The signal fusion module integrates the differential signals acquired by the two paths, eliminates the channel response difference through time sequence calibration, fills in the blank of single-path acquisition through waveform splicing, and corrects the amplitude to compensate for the gain and loss deviation, thereby finally restoring the complete and accurate ultra-narrow partial discharge pulse waveform. The above solves the problem that the traditional peak holding circuit is difficult to capture short pulses due to the limitation of the reverse recovery time of the diode and the slew rate of the operational amplifier, and the high dielectric loss capacitor introduces signal distortion, thereby providing reliable data support with high quality and full feature coverage for partial discharge fault diagnosis, and improving the comprehensiveness and accuracy of ultra-narrow partial discharge pulse detection.

[0008] Preferably, the first acquisition channel module comprises: The transient signal conditioning module is configured to perform transient capture and amplification on the initial partial discharge signal when the first acquisition channel module is in an acquisition phase to obtain a transient signal. The high-speed sample-and-hold module is configured to perform transient feature persistence on the transient signal when the first acquisition channel module is in a holding phase to obtain a first holding signal. The first impedance matching driving module is configured to optimize transmission of the first holding signal to obtain a first differential signal.

[0009] By using the above technical solution, the first acquisition channel module cooperatively realizes accurate capture and high-quality transmission of the ultra-narrow pulse front by quickly capturing and amplifying the pulse front in the acquisition phase through the transient signal conditioning module, stably persisting the transient feature in the holding phase through the high-speed sample-and-hold module, and optimizing transmission through the first impedance matching driving module.

[0010] Preferably, the second acquisition channel module comprises: The low-pass filter module is configured to filter the initial partial discharge signal when the second acquisition channel module is in a preparation phase to obtain a preprocessed signal. a zero-drift amplification module, configured to perform an amplification operation on the preprocessed signal to obtain a collection signal when the second collection channel module is in a collection stage; a precision sample-hold module, configured to perform a transient feature holding operation on the collection signal to obtain a second holding signal when the second collection channel module is in a holding stage; a second impedance matching driving module, configured to perform transmission optimization on the second holding signal to obtain a second differential signal.

[0011] By adopting the above technical solutions, the second collection channel module filters high-frequency noise in the initial partial discharge signal by the low-pass filter module in the preparation stage, and retains the effective components of the pulse trailing edge; the zero-drift amplification module is used to accurately amplify the preprocessed signal in the collection stage, so as to avoid signal distortion; the precision sample-hold module is used to stably latch the trailing edge characteristics of the collection signal in the holding stage; finally, the second impedance matching driving module is used to optimize transmission, and a high-quality second differential signal is output. The sub-modules are coordinated and adapted to the characteristics of the super-narrow partial discharge pulse trailing edge, such as "slow change and easy to be disturbed", and the problems of insufficient capture of trailing edge details and signal distortion in traditional collection are solved.

[0012] Preferably, the transient signal conditioning module comprises: a Schottky diode array, configured to perform a transient capture operation on the initial partial discharge signal to obtain an amplitude-limited signal; a first operational amplifier module, configured to perform an amplification operation on the amplitude-limited signal to obtain a transient signal.

[0013] By adopting the above technical solutions, the Schottky diode array quickly clamps the overvoltage of the initial partial discharge signal by virtue of the ultra-short reverse recovery time, and accurately captures the super-narrow pulse front edge; the first operational amplifier module amplifies the amplitude-limited signal at a high slew rate to restore the front edge steepness characteristics, and the two are coordinated to ensure that the pulse starting details are not lost, thereby solving the problem of lag in response of traditional circuits to transient signals.

[0014] Preferably, the first impedance matching driving module comprises: a first balun transformer, configured to perform transient signal differential conversion on the first holding signal to obtain a first optimized differential signal; and a first high-frequency resistor, configured to perform reflection suppression operation on the first optimized signal to obtain a first differential signal.

[0015] By adopting the above technical solutions, the first balun transformer converts the single-ended first holding signal into a differential signal, effectively suppresses common-mode noise, and adapts to the high-speed transmission requirement of the transient signal; the first high-frequency resistor matches the impedance of the transmission cable, eliminates signal reflection, and the two are coordinated to ensure that the pulse front edge characteristics are not distorted in transmission.

[0016] Preferably, the second impedance matching driving module comprises: a second balun transformer for performing steady-state signal differential conversion on the second holding signal to obtain a second optimized differential signal; and a second high-frequency resistor for performing amplitude and phase fidelity operation on the second optimized signal to obtain a second differential signal.

[0017] By adopting the above technical solutions, the second balun transformer converts the single-ended second holding signal into a differential signal, suppresses common-mode interference to adapt to the transmission of the trailing steady-state signal, the second high-frequency resistor matches the cable impedance to ensure signal amplitude and phase fidelity, and the two work together to ensure the transmission of the pulse trailing edge feature without distortion.

[0018] Preferably, the signal fusion module comprises: a timing calibration module for performing timing alignment on the first differential signal and the second differential signal to obtain a first timing alignment signal and a second timing alignment signal; a waveform splicing module for performing waveform splicing on the first timing alignment signal and the second timing alignment signal to obtain a spliced pulse waveform signal; an amplitude correction module for performing amplitude correction on the spliced pulse waveform signal to obtain an ultra-narrow partial discharge pulse waveform signal.

[0019] By adopting the above technical solutions, the timing calibration module eliminates the time misalignment of the two-way signals to ensure accurate connection of the front and trailing edge feature time dimensions; the waveform splicing module integrates the two-way segmented features to form a complete pulse waveform; and the amplitude correction module compensates for the gain and loss deviation to ultimately restore the real form of the ultra-narrow partial discharge pulse and improve the detection accuracy.

[0020] The application provides an ultra-narrow partial discharge pulse transient detection method based on double-path overlapping acquisition, which is applied to an ultra-narrow partial discharge pulse transient detection system based on double-path overlapping acquisition. The ultra-narrow partial discharge pulse transient detection system based on double-path overlapping acquisition comprises an ultra-high frequency sensor, a first acquisition channel module, a second acquisition channel module and a signal fusion module. The following technical solutions are adopted: The ultra-high frequency sensor converts the ultra-high frequency electromagnetic pulse of the target region into an initial partial discharge signal. The first acquisition channel module and the second acquisition channel module work together to perform double-path parallel overlapping acquisition on the initial partial discharge signal to obtain a first differential signal and a second differential signal. The signal fusion module performs signal fusion on the first differential signal and the second differential signal to obtain an ultra-narrow partial discharge pulse waveform signal.

[0021] By adopting the technical scheme, first, the signal conversion is completed by the ultra-high frequency sensor, then the double-path acquisition module is used for cooperative and overlapped acquisition to cover the whole time period of the pulse, and then the signal fusion module is used for integration and correction, so that the real waveform of the ultra-narrow partial discharge pulse is completely restored, the problems of easy loss of characteristics and signal distortion in traditional single-path acquisition are solved, and the detection reliability is improved.

[0022] The electronic device provided in the application comprises a memory and a processor, the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the steps of the ultra-narrow partial discharge pulse transient detection method based on double-path overlapped acquisition according to any one of the above.

[0023] The computer readable storage medium provided in the application stores a computer program, and the computer program is executed to implement the ultra-narrow partial discharge pulse transient detection method based on double-path overlapped acquisition according to any one of the above.

[0024] In summary, the application has at least one of the following beneficial technical effects: The application converts the ultra-high frequency electromagnetic pulse of the target region into an initial partial discharge signal by the ultra-high frequency sensor, cooperatively carries out double-path parallel overlapped acquisition by the parallel first acquisition channel module and the second acquisition channel module, acquires a first differential signal and a second differential signal, and then fuses the two signals by the signal fusion module to obtain an ultra-narrow partial discharge pulse waveform signal. The application breaks through the limitation of the traditional circuit, widens the dimension by double-path overlapped acquisition, guarantees the feature integrity by the Schottky peak value, realizes accurate capture and feature extraction of the ultra-narrow partial discharge transient pulse, provides reliable data support for partial discharge source positioning and identification, solves the problem of difficult accurate analysis of partial discharge faults caused by the deficiency of traditional circuit acquisition, and improves the detection and diagnosis accuracy and effectiveness. Meanwhile, in view of the defect that the single-path acquisition is easy to lose due to random pulse and low repetition rate, the double-path parallel overlapped acquisition increases the capture probability, makes up for the single-path short board, and guarantees the acquisition comprehensiveness. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural block diagram of an ultra-narrow partial discharge pulse transient detection system based on double-path overlapped acquisition provided by an embodiment of the application; Figure 2 is a structural block diagram of a first acquisition channel module provided by an embodiment of the application; Figure 3 is a structural block diagram of a second acquisition channel module provided by an embodiment of the application; Figure 4 is a structural block diagram of a signal fusion module provided by an embodiment of the application; Figure 5 is a step flowchart of an ultra-narrow partial discharge pulse transient detection method based on double-path overlapped acquisition provided by an embodiment of the application. DETAILED DESCRIPTION

[0026] The present application aims to provide a kind of based on double-path overlap acquisition ultra-narrow partial discharge pulse transient detection system and method, to solve the technical problems that existing partial discharge detection system is difficult to accurately capture ultra-narrow partial discharge pulse, pulse is easily lost, cannot effectively extract key features.

[0027] The present application is through double-path parallel overlap acquisition architecture, first acquisition channel with reverse recovery time <1ns Schottky diode array and high swing rate GaN operational amplifier, break through the capture limit of traditional circuit to <5ns transient pulse;Using double-path time-sharing staggered, alternate maintenance mode, cover pulse full time period, avoid the loss problem caused by single-path acquisition due to pulse random low repetition rate;At the same time, each module selects low-loss, high-stability components (such as PTFE dielectric capacitor, HVC thin film resistor, etc.), combined with signal fusion amplitude correction, inhibit the signal distortion introduced by high dielectric loss capacitor, accurately restore pulse amplitude, solve the three major pain points of prior art.

[0028] The present application is through optimization design, realize transient response time real measurement ≤4.2ns, can accurately capture ultra-narrow pulse;Double-path overlap acquisition makes pulse capture rate improve to 99.9%, greatly superior to 90% of single-path, reduce the loss problem caused by pulse random low repetition rate;Noise peak value keeps error ≤±1mV (when input range ±2V), effectively suppress noise interference, improve amplitude measurement accuracy, provide reliable data support for partial discharge fault accurate diagnosis, solve the short board of traditional acquisition technology Figures 1-4 The present application provides a kind of based on double-path overlap acquisition ultra-narrow partial discharge pulse transient detection system, comprising: Ultrahigh frequency sensor, for converting the ultrahigh frequency electromagnetic pulse of target area into initial partial discharge signal; The first acquisition channel module and the second acquisition channel module are connected in parallel with the ultrahigh frequency sensor; The first acquisition channel module and the second acquisition channel module are used to cooperatively perform double-path parallel overlap acquisition on the initial partial discharge signal, to obtain a first differential signal and a second differential signal; The signal fusion module is used to perform signal fusion on the first differential signal and the second differential signal, to obtain an ultra-narrow partial discharge pulse waveform signal.

[0029] Double-path parallel overlap acquisition means that when two acquisition channel modules work in parallel, time overlap is formed through timing cooperation: one channel acquires while the other channel prepares, one channel maintains the captured features while the other channel acquires subsequent features, and two times of overlap can be alternately formed, to realize gapless capture of complete features of ultra-narrow partial discharge pulse, and avoid the limitations of single-path acquisition.

[0030] Specifically, the first acquisition channel module and the second acquisition channel module are cooperated in time sequence to form an overlapping coverage in time dimension during the acquisition of the initial partial discharge signal: when the first acquisition channel module is in the acquisition stage, the second acquisition channel module synchronously performs preparation work; when the first acquisition channel module enters the holding stage to retain the captured pulse front characteristics, the second acquisition channel module immediately starts acquisition to capture the pulse tail characteristics, forming an overlapping period of "one-way holding and another-way acquisition"; when the second acquisition channel module enters the holding stage to retain the pulse tail characteristics, the first acquisition channel module can start the next round of acquisition, forming a second overlapping. Through this staggered and connected working mode, the complete capture of the ultra-narrow partial discharge pulse from the front to the tail is realized, the loss of pulse characteristics due to the time sequence limitation of single-channel acquisition is avoided, and the comprehensiveness and integrity of signal acquisition are improved.

[0031] It should be noted that the double-channel parallel overlapping acquisition is not a simple signal replication acquisition, but a functional differentiation design based on the characteristic difference of the ultra-narrow partial discharge pulse "steep front and slow tail", that is, the first acquisition channel module focuses on fast response to capture the transient characteristics of the pulse front, and the second acquisition channel module focuses on precise holding to extract the detailed characteristics of the pulse tail. Through the overlapping cooperation in time sequence, the two channels form a complement in their respective advantage frequency bands, which not only solves the contradiction between high-speed response and precise holding in single-channel acquisition, but also eliminates the "blind area" of signal acquisition through the overlapping coverage in time dimension, ensuring that the complete characteristics of the ultra-narrow partial discharge pulse from the beginning to the end can be accurately captured.

[0032] Working principle: The ultra-high frequency sensor converts the target area ultra-high frequency electromagnetic pulse into an initial partial discharge signal. In a double-path parallel overlapping acquisition process, when the first acquisition channel module enters the acquisition stage, the transient signal conditioning module uses a Schottky diode array (such as SMS7630) to limit the amplitude and prevent overvoltage, and then uses a first operational amplifier module (such as QPA9980 GaN operational amplifier) to amplify at a high speed with a 500V / μs pressure swing rate, to capture the pulse front (0-3ns) to obtain a transient signal. At this stage, the second acquisition channel module is in the preparation stage, and the low-pass filter module uses a 1GHz low-pass filter for filtering to output a preprocessed signal, and the two are time overlapped. Then the first acquisition channel module enters the holding stage, the high-speed sample and hold module performs a transient feature persistence operation through a high-speed sample and hold circuit, stops new acquisition and holds the peak value, obtains a first holding signal, and then optimizes the transmission of the first holding signal through the first impedance matching and driving module to output a first differential signal; at the same time, the second acquisition channel module enters the acquisition stage, the zero drift amplification module uses a zero drift operational amplifier for amplification, and the precision sample and hold module captures the pulse trailing edge and latches the peak value within 3-10ns through a precision sample and hold circuit to obtain an acquisition signal, realizing the "first acquisition channel holding-second acquisition channel acquisition" overlap. Then the second acquisition channel module enters the holding stage, the precision sample and hold module performs a transient feature holding operation, stops new acquisition and holds the peak value, obtains a second holding signal, and then optimizes the transmission of the second holding signal through the second impedance matching and driving module to output a second differential signal; at this time, if there is a continuous pulse, the first acquisition channel module can start the next round of acquisition, forming a "second acquisition channel holding-first acquisition channel re-acquisition" secondary overlap. Finally, the signal fusion module performs signal fusion on the first differential signal and the second differential signal to obtain an ultra-narrow partial discharge pulse waveform signal, and through the time overlap cooperation of each stage and the processing of the signal fusion module, the complete characteristics of the ultra-narrow partial discharge pulse are accurately acquired.

[0033] Please refer to Figure 1 and Figure 2 The application provides an ultra-narrow partial discharge pulse transient detection system based on double-path overlapping acquisition. The transient signal conditioning module is used for performing transient capture and amplification operations on the initial partial discharge signal when the first acquisition channel module is in the acquisition stage, to obtain a transient signal. The high-speed sample and hold module is used for performing a transient feature persistence operation on the transient signal when the first acquisition channel module is in the holding stage, to obtain a first holding signal. The first impedance matching and driving module is used for optimizing the transmission of the first holding signal to obtain a first differential signal.

[0034] The transient signal conditioning module comprises: The Schottky diode array is used for performing a transient capture operation on the initial partial discharge signal to obtain a limiting signal. The first operational amplifier module is used to amplify the limited signal to obtain a transient signal.

[0035] The first impedance matching driving module includes: a first balun transformer, configured to perform transient signal differential conversion on the first hold signal to obtain a first optimized differential signal; The first high-frequency resistor is used to perform a reflection suppression operation on the first optimized signal to obtain a first differential signal.

[0036] In the embodiment of the present invention, the first acquisition channel module realizes efficient acquisition of ultra-narrow partial discharge pulse fronts through precise selection and coordination of various submodules.

[0037] The transient signal conditioning module includes a Schottky diode array and a first op amp module. The Schottky diode array uses a model with a reverse recovery time of <1ns (such as the SMS7630). The parallel layout reduces the influence of junction capacitance, quickly clamps the initial local discharge signal overvoltage, accurately captures the ultra-narrow pulse leading edge of <5ns, and outputs a limiting signal. A GaN (Gallium Nitride) op amp (such as the QPA9980) is used as the first op amp module. With a high slew rate of 500V / μs, it accurately amplifies the limiting signal, restores the steep change characteristics of the pulse leading edge, outputs the transient signal, and ensures that the pulse starting details are not lost. At the same time, PTFE (polytetrafluoroethylene) dielectric RF capacitors (such as the GQM series, which have a low dielectric loss factor) are used to further optimize signal transmission and reduce energy loss. The high-speed sample and hold module is constructed using a high-speed analog switch (such as the ADG1414) and high-frequency ceramic capacitors. The analog switch has a ns-level switching speed and quickly latches the transient signal peak. The ceramic capacitors The first impedance matching driver module includes a first balun transformer (such as the ADE-1+ balun transformer) and a first high-frequency resistor. The first balun transformer converts the single-ended first hold signal into a differential signal, suppressing common-mode noise and optimizing signal transmission. The first high-frequency resistor (50Ω RFR50-60 high-frequency resistor) matches the transmission cable impedance, eliminating signal reflections and outputting the first differential signal. This ensures high-quality transmission of leading-edge features to subsequent modules, laying the foundation for dual-path fusion.

[0038] In a specific implementation, when the target area generates a UHF electromagnetic pulse, the UHF sensor converts it into an initial partial discharge signal, which is first input into a transient signal conditioning module, wherein a Schottky diode array uses the characteristics of reverse recovery time <1 ns and parallel layout to reduce junction capacitance to perform transient capture on S0, quickly clamp overvoltage, and accurately capture <5 ns super-narrow pulse front, output an amplitude limiting signal, then a GaN operational amplifier as a first operational amplifier module amplifies the amplitude limiting signal with a high voltage swing of 500 V / μs to restore the pulse front steepness characteristics, while a PTFE dielectric radio frequency capacitor optimizes signal transmission to reduce energy loss, and finally outputs a transient signal; then, the transient signal enters a high-speed sampling and holding module, a high-speed analog switch quickly latches the peak value of the transient signal with a switching speed of ns level, and a high-frequency ceramic capacitor maintains the signal amplitude stable in the holding stage by virtue of the low loss characteristic, and completes the transient feature persistence operation to obtain a first holding signal; then, the first holding signal is input into a first impedance matching and driving module, a first balun transformer converts the single-ended first holding signal into a differential signal to suppress common mode noise, and a first high-frequency resistor eliminates signal reflection by matching the impedance of the transmission cable, and finally obtains a first differential signal and transmits it to a signal fusion module. This process solves the problem of capturing super-narrow pulses caused by slow response of traditional circuits through the cooperation of the Schottky diode array and the GaN operational amplifier, accurately preserves the pulse front characteristics, and ensures that the feature data is stable and not distorted in the holding stage through the high-speed sampling and holding module. The impedance matching and driving module guarantees the high quality of signal transmission, avoids feature damage, and provides reliable front feature data support for subsequent double-channel signal fusion and partial discharge source positioning and identification, realizing complete and efficient processing of super-narrow partial discharge pulses from capture, persistence to transmission.

[0039] Please refer to Figure 1 and Figure 3 , the application provides a kind of based on double-path overlap acquisition's super-narrow partial discharge pulse transient detection system, second acquisition channel module includes: Low-pass filter module, for when second acquisition channel module is in preparation stage, initial partial discharge signal is filtered, and pre-processing signal is obtained; Zero drift amplification module, for when second acquisition channel module is in acquisition stage, pre-processing signal is amplified, and acquisition signal is obtained; Precision sampling and holding module, for when second acquisition channel module is in holding stage, acquisition signal is operated with transient feature holding, and second holding signal is obtained; Second impedance matching and driving module, for transmission optimization of second holding signal, and second differential signal is obtained.

[0040] Therefore, the second impedance matching and driving module includes: The second balun transformer is used for steady-state signal differential conversion on the second holding signal to obtain a second optimized differential signal. The second high-frequency resistor is used for amplitude and phase fidelity operation on the second optimized signal to obtain a second differential signal.

[0041] In the embodiment of the application, the second acquisition channel module is designed by the sub-modules for the characteristics of the ultra-narrow partial discharge pulse tail, and stable acquisition and reliable transmission are realized.

[0042] The low-pass filter module adopts a 1GHz low-pass filter (such as a BLP-1G+ low-pass filter), uses the high cutoff frequency and steep filtering characteristics, effectively suppresses the high-frequency noise in the initial partial discharge signal, retains the effective components of the pulse tail (3-10 ns), and outputs a preprocessed signal, laying the foundation for subsequent accurate acquisition.

[0043] The zero-drift amplifier module adopts a zero-drift operational amplifier (such as TIOPA2188), uses the μV level of the offset voltage and the extremely low temperature drift characteristics, accurately amplifies the preprocessed signal, avoids the signal distortion caused by the temperature drift and offset of the traditional operational amplifier, restores the subtle characteristics of the pulse tail, and outputs an acquisition signal.

[0044] The precision sampling and holding module is constructed by a precision sampling and holding circuit (such as an F338 capacitor combined with a high-speed switch), the F338 capacitor has low leakage and high stability, and the high-speed switch has a fast latching function, so that the peak value of the acquisition signal is stably maintained, the pulse tail characteristics are stored, and a second holding signal is output.

[0045] In the second impedance matching and driving module, the second balun transformer (such as an ADE-2+ balun transformer) converts the single-ended second holding signal into a differential signal, suppresses common-mode interference, and optimizes the transmission mode; the second high-frequency resistor (50Ω HVC thin film resistor) matches the impedance of the transmission cable, performs amplitude and phase fidelity operation on the second optimized signal, ensures that the signal amplitude and phase are not distorted in transmission, and outputs a second differential signal, providing high-quality tail characteristic data for double-channel fusion, and cooperating with the first acquisition channel to realize full-time period characteristic coverage of the ultra-narrow partial discharge pulse.

[0046] In a specific implementation, when the ultrahigh frequency sensor outputs an initial partial discharge signal, the second acquisition channel module enters the working process and is in the preparation stage, the low-pass filter module uses a 1GHz low-pass filter for filtering, uses its high cutoff frequency and steep filtering characteristics to suppress high-frequency noise and retain the effective components of the pulse tail (3-10ns), and outputs a pretreatment signal; then the second acquisition channel module enters the acquisition stage, the zero drift operational amplifier in the zero drift amplification module amplifies the pretreatment signal accurately by virtue of the μV level of the offset voltage and the extremely low temperature drift characteristics, restores the subtle features of the pulse tail, and obtains an acquisition signal; then it enters the holding stage, the precision sampling holding module is constructed by Vishay F338 capacitor and high-speed switch, and the F338 capacitor has low leakage, high stability and fast latching function of high-speed switch, which can stabilize the peak value of the acquisition signal and store the pulse tail characteristics, and output the second holding signal; then the second holding signal enters the second impedance matching driving module, the second balun transformer converts the single-ended signal into a differential signal to suppress common-mode interference, the 50Ω Vishay high-precision resistance matches the impedance of the transmission cable, and the amplitude and phase of the second optimized signal are preserved to output the second differential signal. In this process, each module is accurately selected and cooperated, the low-pass filter lays the foundation for acquisition, the zero drift amplifier restores the subtle features, the precision sampling holding stabilizes the storage, and the impedance matching driving ensures high-quality transmission. Cooperating with the first acquisition channel, it realizes the full-time characteristic coverage of the ultra-narrow partial discharge pulse, so that the subsequent signal fusion module can obtain complete pulse information, improves the accuracy and reliability of partial discharge fault diagnosis, solves the problems of easy loss of tail characteristics and easy distortion of signal transmission in traditional single-channel acquisition, and provides stable and accurate technical support for ultra-narrow partial discharge pulse detection.

[0047] It is worth mentioning that the first impedance matching drive module focuses on the ultra-narrow pulse front transient characteristics, and ADE-1 + balun transformer is selected to match 50Ω RFR50-60 high-frequency resistance. ADE-1 + balun transformer can quickly respond to the steep change of <5ns pulse front, convert single-ended signal to differential signal, suppress common-mode noise, and adapt to the high-speed transmission demand of front transient signal; the second impedance matching drive module aims at the pulse trailing edge steady state characteristics, and ADE-2 + balun transformer and 50Ω HVC thin film resistance are used. ADE-2 + balun transformer focuses more on the amplitude and phase fidelity conversion of the trailing edge signal, and HVC thin film resistance guarantees the undistorted transmission of the amplitude and phase of the trailing edge signal due to its low temperature coefficient and high stability. The difference between the two is due to the different needs of the pulse front "transient high speed" and the trailing edge "steady state fidelity". When working together, the first module accurately captures the <5ns front pulse, breaking through the limitations of traditional peak holding circuits that are difficult to capture due to the diode reverse recovery time (> 10ns) and insufficient op-amp slew rate; the second module stabilizes the trailing edge characteristics, and cooperates with double-channel parallel acquisition to avoid the problem of pulse loss caused by single-channel acquisition, and together provides support for high-precision acquisition and transmission of ultra-narrow local discharge pulse full-time characteristics, solving the deficiencies of traditional schemes in transient pulse capture and pulse loss.

[0048] Referring to Figure 1 and Figure 4 The application provides an ultra-narrow local discharge pulse transient detection system based on double-channel overlapping acquisition, and a signal fusion module comprises: a timing calibration module, configured to perform timing alignment on the first differential signal and the second differential signal to obtain a first timing alignment signal and a second timing alignment signal; a waveform splicing module, configured to perform waveform splicing on the first timing alignment signal and the second timing alignment signal to obtain a spliced pulse waveform signal; an amplitude correction module, configured to perform amplitude correction on the spliced pulse waveform signal to obtain an ultra-narrow local discharge pulse waveform signal.

[0049] In the embodiment of the present application, when the first differential signal output by the first acquisition channel and the second differential signal output by the second acquisition channel are transmitted to the signal fusion module, the timing calibration module first aligns the timing of the two differential signals according to the characteristic points (such as the starting time of the front edge and the ending time of the rear edge) of the pulse front edge and rear edge, accurately matches the corresponding relationship of the two signals on the time axis, and outputs the first timing alignment signal and the second timing alignment signal; then, the waveform splicing module splices the two signals with aligned timing, seamlessly connects the front edge part of the first timing alignment signal with the rear edge part of the second timing alignment signal, and forms a spliced pulse waveform signal that completely covers the 0-10 ns ultra-narrow partial discharge pulse period; subsequently, the amplitude correction module corrects the amplitude of the spliced waveform based on the gain difference (such as the different amplification multiples of the first operational amplifier module and the zero-drift amplifier module) and transmission loss of the two signal acquisition channels, and finally obtains the ultra-narrow partial discharge pulse waveform signal through a pre-set correction algorithm. In this process, the timing calibration module solves the time misalignment problem caused by the response difference of the two channels, ensuring that the pulse front and rear edge features accurately connect in the time dimension; the waveform splicing module integrates the segmented features of the two channels, filling the gap of the information easily lost by single-channel acquisition; and the amplitude correction module eliminates the amplitude deviation caused by the channel gain and transmission loss, and the three modules work together to restore the real waveform of the ultra-narrow partial discharge pulse, solving the problem that the traditional single-channel acquisition is difficult to capture the pulse features completely and the waveform is easily distorted, providing high-precision, full-period coverage pulse waveform data for accurate diagnosis of partial discharge faults, and improving the recognition and analysis capability of the detection system for ultra-narrow partial discharge pulses.

[0050] It should be noted that the timing calibration module extracts the characteristic points by the threshold crossing method, and identifies the starting / ending time of the front edge and rear edge according to the 10% / 90% peak threshold after filtering the differential signal, so as to realize accurate timing alignment. Specifically, The first differential signal and the second differential signal are subjected to sliding window denoising (such as rectangular window average filtering, and the window length is 3-5 sampling points); The voltage threshold (such as 10% of the pulse peak value as the front edge starting threshold, and 90% as the front edge ending threshold; and the rear edge is opposite) is set; When the signal voltage first crosses the starting threshold, it is marked as the front edge starting time; when it crosses the ending threshold, it is marked as the front edge ending time; and the rear edge characteristic point is extracted in the same way. Through this algorithm, the time nodes of the pulse front and rear edge can be accurately identified, providing a clear reference for timing alignment and solving the problem of “ambiguous characteristic point extraction”.

[0051] The amplitude correction module pre-calibrates the actual gain of the operational amplifier based on the gain compensation method, and eliminates the amplitude deviation through a compensation formula that fuses the gains of the two signals; Specifically, The actual gain G of the first operational amplifier module is pre-calibrated1实际 , the actual gain G of the second acquisition channel zero drift operational amplifier 2实际 (measured by a standard signal source and an oscilloscope, and a gain-frequency curve is obtained); Suppose that the amplitude of the first differential signal is V1 and the amplitude of the second differential signal is V2, then the corrected amplitude V 修正 satisfies: The gain difference of the two signals is accurately compensated, and the amplitude accuracy is ensured.

[0052] The waveform splicing module adopts a linear interpolation method to linearly fit the sampling points in the connection area to generate transition points, so that the waveform is continuous. The waveform splicing module adopts a linear interpolation method to process the connection area of the two signals: extract the end segment (such as the last 5 sampling points) of the first time sequence alignment signal and the start segment (such as the first 5 sampling points) of the second time sequence alignment signal; linearly fit the sampling points of the two segments of signals to calculate the amplitude transition coefficient of adjacent points; According to the transition coefficient, the interpolation points of the connection area are generated to replace the original signal jump points, so that the spliced waveform is continuous and smooth. Please refer to Figure 5 The control method of the ultra-narrow partial discharge pulse transient detection system based on double-channel overlapping acquisition provided by the application comprises: Step 101, converting the ultra-high frequency electromagnetic pulse of the target area into an initial partial discharge signal through an ultra-high frequency sensor; In the embodiment of the application, the ultra-high frequency electromagnetic pulse of the target area is converted into an initial partial discharge signal through an ultra-high frequency sensor. Specifically, the ultra-high frequency sensor uses electromagnetic coupling principle to convert the ultra-high frequency electromagnetic pulse (frequency range is usually 300MHz-3GHz) generated in the target area (such as the inside of an electrical equipment) into an initial partial discharge signal in the form of an electrical signal, which contains the complete characteristics of the ultra-narrow partial discharge pulse from the front edge to the back edge, but may be accompanied by environmental electromagnetic noise interference.

[0053] Step 102, performing double-channel parallel overlapping acquisition on the initial partial discharge signal through the first acquisition channel module and the second acquisition channel module to obtain a first differential signal and a second differential signal; In the embodiment of the present application, the first acquisition channel module and the second acquisition channel module cooperate to perform double-path parallel overlapping acquisition on the initial partial discharge signal to obtain a first differential signal and a second differential signal. In this step, the double-path acquisition realizes overlapping coverage in the time dimension through timing cooperation. When the first acquisition channel module detects the initial partial discharge signal trigger (for example, the signal amplitude exceeds a preset threshold), the acquisition stage is entered. The transient signal conditioning module rapidly performs amplitude limiting and overvoltage protection on the initial partial discharge signal through the Schottky diode array, thereby avoiding damage to subsequent modules due to overvoltage and accurately capturing the pulse front (0-3 ns) characteristics to output an amplitude-limited signal. Then, the first operational amplifier module amplifies the amplitude-limited signal at a high voltage swing to restore the steep characteristics of the pulse front, thereby obtaining a transient signal. At the same time that the first acquisition channel module enters the acquisition stage, the second acquisition channel module is in the preparation stage. The low-pass filter module filters the initial partial discharge signal to suppress high-frequency noise and retain the effective components of the pulse tail (3-10 ns) to output a preprocessed signal for subsequent acquisition. At this time, the working time of the two channels overlaps. Next, the first acquisition channel module enters the holding stage. The high-speed sampling and holding module performs transient characteristic persistence operation on the transient signal to quickly latch the signal peak value and stably hold it to obtain a first holding signal. Then, the first impedance matching and driving module converts the single-ended signal into a differential signal while eliminating signal reflection through impedance matching to output the first differential signal. At the same time that the first acquisition channel module enters the holding stage, the second acquisition channel module enters the acquisition stage. The zero-drift amplifier module accurately amplifies the preprocessed signal to avoid signal distortion caused by operational amplifier misadjustment or temperature drift and restores the subtle characteristics of the pulse tail to obtain an acquisition signal. Then, the precision sampling and holding module performs transient characteristic holding operation on the acquisition signal to stably latch the signal peak value and persist the pulse tail characteristics to obtain a second holding signal. Subsequently, the second acquisition channel module enters the holding stage. The second impedance matching and driving module converts the single-ended second holding signal into a differential signal to suppress common-mode interference and realizes signal amplitude and phase faithful transmission through impedance matching to output the second differential signal. If there are continuous pulses, the first acquisition channel module can start the next round of acquisition during the holding stage of the second acquisition channel module to form secondary overlapping to ensure no signal acquisition blind area.

[0054] Step 103, performing signal fusion on the first differential signal and the second differential signal through a signal fusion module to obtain an ultra-narrow partial discharge pulse waveform signal.

[0055] In the embodiment of the application, the first differential signal and the second differential signal are signal fused by a signal fusion module to obtain an ultra-narrow partial discharge pulse waveform signal; the specific process is as follows: a time sequence calibration module aligns the time axis of the first differential signal and the second differential signal according to characteristic points such as the starting time of the pulse front edge and the ending time of the trailing edge, to ensure accurate matching of the two signals in the time dimension, and obtain a first time sequence alignment signal and a second time sequence alignment signal; a waveform splicing module seamlessly connects the front edge part of the first time sequence alignment signal after time sequence alignment with the trailing edge part of the second time sequence alignment signal, to form a spliced pulse waveform signal covering the whole time period (0-10 ns) of the pulse; and a magnitude correction module corrects the amplitude of the spliced waveform based on factors such as the gain difference between the first operational amplifier module and the zero-drift amplifier module and signal loss in the transmission process, using algorithms such as the least squares method, to eliminate amplitude deviation, and finally obtain a complete and true ultra-narrow partial discharge pulse waveform signal.

[0056] The application solves the contradiction between high-speed capture of the pulse front edge and precise maintenance of the trailing edge by means of the time sequence cooperation of double-channel parallel overlapping acquisition, and realizes gapless and high-precision acquisition of the whole time period characteristics of the ultra-narrow partial discharge pulse by combining the accurate processing of the signal fusion module, thereby providing reliable waveform data support for accurate diagnosis of partial discharge faults.

[0057] The application converts the target area ultra-high frequency electromagnetic pulse into an initial partial discharge signal by means of the ultra-high frequency sensor, and acquires the first differential signal and the second differential signal by means of the cooperation of the parallel first acquisition channel module and the second acquisition channel module to carry out double-channel parallel overlapping acquisition, and then fuses the two signals by means of the signal fusion module to obtain the ultra-narrow partial discharge pulse waveform signal. The application breaks through the limitations of traditional circuits, widens the dimension by double-channel overlapping acquisition, guarantees the integrity of the characteristics by means of the Schottky peak value, realizes accurate capture and feature extraction of the ultra-narrow partial discharge transient pulse, provides reliable data support for partial discharge source positioning and identification, solves the problem of difficult accurate analysis of partial discharge faults caused by the deficiency of traditional circuit acquisition, and improves the detection and diagnosis accuracy and effectiveness; at the same time, in view of the defect that single-channel acquisition is easy to lose due to random pulse and low repetition rate, the application increases the capture probability by means of double-channel parallel overlapping acquisition, makes up for the shortcomings of single-channel, and guarantees the comprehensiveness of acquisition.

[0058] The electronic device of the embodiment of the application comprises a memory and a processor, and the memory stores a computer program; when the computer program is executed by the processor, the processor executes the ultra-narrow partial discharge pulse transient detection method based on double-channel overlapping acquisition according to any one of the above embodiments.

[0059] The memory can be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. The memory has storage space for program code for carrying out any of the method steps described above. For example, the storage space for program code can comprise individual program codes for implementing the various steps in the above methods, respectively. The program codes can be read from or written to one or more computer program products. The computer program products comprise program code carriers such as hard disks, compact disks (CDs), memory cards or floppy disks. The program codes can be compressed, for example, in a suitable form. The codes, when run by a computing processing device, cause the computing processing device to carry out the individual steps in the methods described above.

[0060] The embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed to realize the method for detecting ultra-narrow partial discharge pulse transients based on double-path overlapping acquisition according to any embodiment of the present application.

[0061] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, and will not be described here.

[0062] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the above-described device embodiments are merely schematic, and the division of the units is merely a logical function division, and there can be another division manner in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0063] The units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, that is, can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0064] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0065] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes The embodiments of the specific implementation are the preferred embodiments of the present application, and are not limited to the protection scope of the present application, wherein the same parts are denoted by the same reference numerals. Therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. An ultra-narrow partial discharge pulse transient detection system based on dual-path overlapping acquisition, characterized in that: include: A UHF sensor, used to convert the UHF electromagnetic pulses in the target area into initial local discharge signals; The first acquisition channel module and the second acquisition channel module are connected in parallel with the UHF sensor; The first acquisition channel module and the second acquisition channel module are used to collaboratively perform dual-path parallel overlapping acquisition of the initial partial discharge signal to obtain a first differential signal and a second differential signal; A signal fusion module is used to fuse the first differential signal and the second differential signal to obtain an ultra-narrow partial discharge pulse waveform signal.

2. The ultra-narrow partial discharge pulse transient detection system based on dual-path overlapping acquisition according to claim 1, characterized in that: The first acquisition channel module includes: a transient signal conditioning module, configured to perform transient capture and amplification operations on the initial partial discharge signal to obtain a transient signal when the first acquisition channel module is in the acquisition phase; a high-speed sampling and holding module, configured to perform a transient feature persistence operation on the transient signal when the first acquisition channel module is in a holding phase, to obtain a first held signal; The first impedance matching driving module is configured to perform transmission optimization on the first holding signal to obtain a first differential signal.

3. The ultra-narrow partial discharge pulse transient detection system based on dual-path overlapping acquisition according to claim 1, characterized in that: The second acquisition channel module includes: a low-pass filtering module, configured to filter the initial partial discharge signal to obtain a preprocessed signal when the second acquisition channel module is in the preparation stage; a zero-drift amplification module, configured to amplify the preprocessed signal to obtain an acquisition signal when the second acquisition channel module is in an acquisition phase; a precision sampling and holding module, configured to perform a transient feature holding operation on the acquisition signal when the second acquisition channel module is in the holding phase, to obtain a second held signal; The second impedance matching driving module is used to optimize the transmission of the second holding signal to obtain a second differential signal.

4. The ultra-narrow partial discharge pulse transient detection system based on dual-path overlapping acquisition according to claim 2, characterized in that: The transient signal conditioning module includes: A Schottky diode array is used to perform a transient capture operation on the initial local discharge signal to obtain a limiting signal; The first operational amplifier module is used to amplify the amplitude limiting signal to obtain a transient signal.

5. The ultra-narrow partial discharge pulse transient detection system based on dual-path overlapping acquisition according to claim 2, characterized in that: The first impedance matching driving module includes: a first balun transformer, configured to perform transient signal differential conversion on the first hold signal to obtain a first optimized differential signal; The first high-frequency resistor is used to perform a reflection suppression operation on the first optimized signal to obtain a first differential signal.

6. The ultra-narrow partial discharge pulse transient detection system based on dual-path overlapping acquisition according to claim 3, characterized in that: Therefore, the second impedance matching driver module includes: a second balun transformer, configured to perform steady-state signal differential conversion on the second hold signal to obtain a second optimized differential signal; The second high-frequency resistor is used to perform an amplitude and phase fidelity operation on the second optimized signal to obtain a second differential signal.

7. An ultra-narrow partial discharge pulse transient detection system based on dual-path overlapping acquisition according to any one of claims 1 to 6, characterized in that: The signal fusion module includes: a timing calibration module, configured to perform timing alignment on the first differential signal and the second differential signal to obtain a first timing alignment signal and a second timing alignment signal; a waveform splicing module, configured to perform waveform splicing on the first timing alignment signal and the second timing alignment signal to obtain a spliced ​​pulse waveform signal; The amplitude correction module is used to perform amplitude correction on the spliced ​​pulse waveform signal to obtain an ultra-narrow partial discharge pulse waveform signal.

8. A method for transient detection of ultra-narrow partial discharge pulses based on dual-path overlapping acquisition, characterized in that: The ultra-narrow partial discharge pulse transient detection system based on dual-channel overlapping acquisition, applied to any one of claims 1 to 7, comprises an ultra-high frequency sensor, a first acquisition channel module, a second acquisition channel module, and a signal fusion module, and the method comprises: The ultra-high frequency electromagnetic pulses in the target area are converted into initial local discharge signals by the ultra-high frequency sensor; Performing dual-path parallel overlapping acquisition of the initial partial discharge signal through the first acquisition channel module and the second acquisition channel module in collaboration to obtain a first differential signal and a second differential signal; The first differential signal and the second differential signal are fused by the signal fusion module to obtain an ultra-narrow partial discharge pulse waveform signal.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the ultra-narrow partial discharge pulse transient detection method based on dual-path overlapping acquisition as claimed in claim 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the ultra-narrow partial discharge pulse transient detection method based on dual-path overlapping acquisition as claimed in claim 8 is implemented.

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