Multi-band end screen signal processing device, sleeve end screen monitoring equipment and electric power system

Abstract

The invention relates to a multi-band end screen signal processing device, a sleeve end screen monitoring device and a power system. According to the device, a front-end conditioning module is connected with a multi-frequency-band current sensor and used for receiving a multi-frequency-band end screen sensing signal output by the multi-frequency-band current sensor, conducting multi-frequency-band anti-interference conditioning on the multi-frequency-band end screen sensing signal and outputting a multi-frequency-band end screen conditioning signal; the synchronous acquisition module is connected with the front-end conditioning module and is used for carrying out synchronous sampling on the multi-band end screen conditioning signal based on a unified time reference and a unified phase reference and outputting a multi-band end screen sampling signal with a unified timestamp; the fusion processing module is connected with the synchronous acquisition module and is used for performing time domain alignment, amplitude normalization, phase calibration, feature extraction and cross-band correlation analysis processing on the multi-band end screen sampling signals with the unified timestamps and outputting multi-band fusion data; and the communication module is connected with the fusion processing module and is used for sending the multi-band fusion data to the remote analysis module.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-band signal processing, in particular to a multi-band terminal screen signal processing device, a bushing terminal screen monitoring device and a power system. BACKGROUND

[0002] The transformer is the core hub equipment of the smart grid, and its safe and stable operation is directly related to the power supply reliability of the power grid. The bushing is a key insulation component of the transformer, and the terminal screen leakage current of the bushing contains multi-band characteristic signals such as power frequency, intermediate frequency and high frequency. Changes in these signals can directly reflect potential faults such as transient overvoltage and partial discharge of the bushing, and therefore become the core object of bushing state monitoring.

[0003] In related technologies, although the multi-band current sensor can capture characteristic signals in different frequency domains, the sampling time bases of the output signals of each frequency band are not unified, there is a significant time sequence deviation, which leads to time misalignment and amplitude drift in the rear-end fusion calculation, seriously affecting the comprehensive judgment accuracy of key signals such as transient overvoltage and partial discharge, and it is difficult to meet the accurate transformer state evaluation requirements. SUMMARY

[0004] Therefore, it is necessary to provide a multi-band terminal screen signal processing device, a bushing terminal screen monitoring device and a power system, which can eliminate the inherent time sequence deviation of each frequency band signal and provide reliable multi-band fusion data for transformer state evaluation.

[0005] In a first aspect, an embodiment of the present application provides a multi-band terminal screen signal processing device, which comprises:

[0006] A front-end conditioning module connected with a multi-band current sensor, configured to receive multi-band terminal screen sensing signals corresponding to a bushing terminal screen of a power device output by the multi-band current sensor, and perform frequency band anti-interference conditioning on the multi-band terminal screen sensing signals to output multi-band terminal screen conditioning signals;

[0007] A synchronous acquisition module connected with the front-end conditioning module, configured to perform synchronous sampling on the multi-band terminal screen conditioning signals based on a unified time reference and a unified phase reference, and output multi-band terminal screen sampling signals with a unified timestamp;

[0008] A fusion processing module connected with the synchronous acquisition module, configured to perform time domain alignment, amplitude normalization, phase calibration, feature extraction and cross-band correlation analysis processing on the multi-band terminal screen sampling signals with the unified timestamp, and output multi-band fusion data;

[0009] A communication module connected with the fusion processing module, configured to send the multi-band fusion data to a remote analysis module.

[0010] In one embodiment, the synchronous acquisition module includes:

[0011] Clock source circuit, used to generate sampling reference time signal;

[0012] A clock distribution circuit, connected to the clock source circuit, is used to generate a unified time reference signal and a unified phase reference signal based on the sampling reference time signal;

[0013] A synchronous triggering circuit, connected to the clock distribution circuit, is used to generate synchronous triggering pulses based on the unified time reference signal and the unified phase reference signal;

[0014] Multiple analog-to-digital conversion circuits are provided, one of which corresponds to a frequency band of the multi-band end-screen conditioning signal. The analog-to-digital conversion circuit is connected to the front-end conditioning module, the clock distribution circuit, and the synchronization trigger circuit. It is used to synchronously sample the end-screen conditioning signal of the target frequency band in the multi-band end-screen conditioning signal based on the unified time reference signal, the unified phase reference signal, and the synchronization trigger pulse, and output the end-screen sampling signal of the target frequency band with a unified timestamp.

[0015] In one embodiment, the plurality of analog-to-digital conversion circuits include an analog-to-digital conversion circuit for a first frequency band, an analog-to-digital conversion circuit for a second frequency band, and an analog-to-digital conversion circuit for a third frequency band.

[0016] The frequencies of the first frequency band, the second frequency band, and the third frequency band increase sequentially.

[0017] The sampling rates of the analog-to-digital converter circuits in the first frequency band, the second frequency band, and the third frequency band increase sequentially.

[0018] In one embodiment, the front-end conditioning module includes:

[0019] An amplifier circuit, connected to the multi-band current sensor, is used to amplify the target frequency band end-screen sensing signal in the multi-band end-screen sensing signal and output the amplified signal.

[0020] A filtering circuit, connected to the amplification circuit, is used to filter the amplified signal and output a filtered signal.

[0021] A gain circuit, connected to the filter circuit, is used to adjust the amplitude of the filtered signal and output the amplitude-adjusted signal.

[0022] A protection circuit, connected to the gain circuit, is used to perform overvoltage limiting processing on the amplitude-adjusted signal and output the final screen conditioning signal of the target frequency band.

[0023] In one of the embodiments, the amplification circuit comprises a low-noise amplifier; the low-noise amplifier is connected with the multi-band current sensor, and is configured to amplify the end screen sensing signal of the target frequency band in the multi-band end screen sensing signal, and output the amplified signal.

[0024] The gain circuit comprises an automatic gain control circuit; the automatic gain control circuit is connected with the filter circuit, and is configured to adjust the amplitude of the filtered signal, and output the amplitude-adjusted signal.

[0025] In one of the embodiments, the fusion processing module comprises:

[0026] The time domain alignment circuit is connected with the synchronous acquisition module, and is configured to perform time alignment and interpolation correction on the multi-band end screen sampling signal with unified time stamp, and output the time domain aligned signal.

[0027] The amplitude normalization circuit is connected with the time domain alignment circuit, and is configured to remove the amplitude deviation of the time domain aligned signal, and output the amplitude normalized signal.

[0028] The phase calibration circuit is connected with the amplitude normalization circuit, and is configured to compensate and correct the phase deviation of the amplitude normalized signal, and output the phase calibrated signal.

[0029] The feature extraction circuit is connected with the phase calibration circuit, and is configured to extract key feature parameters of the phase calibrated signal in a frequency band, and output the multi-dimensional feature signal.

[0030] The cross-band correlation analysis circuit is connected with the feature extraction circuit, and is configured to perform cross-band correlation analysis on the output multi-dimensional feature signal, and output the multi-band fusion data.

[0031] In one of the embodiments, the fusion processing module comprises a field programmable gate array circuit.

[0032] In one of the embodiments, the device further comprises:

[0033] The remote analysis module is configured to receive the multi-band fusion data, and determine the state monitoring result of the end screen of the power device bushing according to the multi-band fusion data.

[0034] In a second aspect, the embodiments of the present application provide a bushing end screen monitoring device, comprising a multi-band current sensor and a multi-band end screen signal processing device as described in the first aspect.

[0035] The multi-band current sensor is installed on the bushing end screen.

[0036] The multi-band end screen signal processing device is connected with the multi-band current sensor.

[0037] In a third aspect, the embodiments of the present application provide a power system, comprising a transformer and the bushing tap monitor device according to the second aspect; the multi-band current sensor is installed on the bushing tap of the transformer.

[0038] The multi-band tap signal processing device, the bushing tap monitor device and the power system, comprise a front-end conditioning module, a synchronous acquisition module, a fusion processing module and a communication module. The front-end conditioning module is connected with the multi-band current sensor, used for receiving the multi-band tap sensing signal corresponding to the bushing tap of the power device output by the multi-band current sensor, and performing frequency-band anti-interference conditioning on the multi-band tap sensing signal, and outputting a multi-band tap conditioning signal; the synchronous acquisition module is connected with the front-end conditioning module, used for synchronously sampling the multi-band tap conditioning signal based on a unified time reference and a unified phase reference, and outputting a multi-band tap sampling signal with a unified time stamp; the fusion processing module is connected with the synchronous acquisition module, used for performing time domain alignment, amplitude normalization, phase calibration, feature extraction and cross-band correlation analysis processing on the multi-band tap sampling signal with the unified time stamp, and outputting multi-band fusion data; and the communication module is connected with the fusion processing module, used for sending the multi-band fusion data to a remote analysis module.

[0039] The frequency-band anti-interference conditioning of the front-end conditioning module provides a clean signal basis for subsequent synchronous acquisition and fusion processing, avoiding the aggravation of noise interference and determination errors; the dual-reference synchronization and unified time stamp of the synchronous acquisition module solve the problem of time sequence deviation; the time domain alignment, amplitude normalization, phase calibration, feature extraction and cross-band correlation analysis processing of the fusion processing module solve the problem of inaccurate fusion, ensuring accurate collaborative analysis of multi-band signals; and the communication module transmits the fusion data to a remote analysis device, finally supporting accurate monitoring and evaluation of power equipment states. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0041] Figure 1 FIG. 1 is a structural schematic diagram of a multi-band tap signal processing device according to an embodiment of the present application;

[0042] Figure 2 FIG. 2 is another structural schematic diagram of a multi-band tap signal processing device according to an embodiment of the present application;

[0043] Figure 3 a structure diagram of a front-end conditioning module according to an embodiment;

[0044] Figure 4 a structure diagram of a front-end conditioning module according to an embodiment;

[0045] Figure 5 a structure diagram of a fusion processing module according to an embodiment. DETAILED DESCRIPTION

[0046] In order to facilitate the understanding of the present application, a more complete and thorough description of the present application will be made with reference to the accompanying drawings. The accompanying drawings show embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0048] It can be understood that the terms "first", "second", and the like used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the other element. For example, without departing from the scope of the present application, a first resistor can be referred to as a second resistor, and similarly, a second resistor can be referred to as a first resistor. The first resistor and the second resistor are both resistors, but they are not the same resistor.

[0049] It can be understood that "connection" in the following embodiments means that the circuits, modules, units, etc. connected to each other have the transmission of electrical signals or data.

[0050] It can be understood that "at least one" means one or more, and "multiple" means two or more. "At least part of the element" means part or all of the element.

[0051] As used herein, the singular forms "a", "an" and "the" can include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "comprise / comprising" or "have / having" specifies the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in the specification includes any and all combinations of the related listed items.

[0052] The multi-band screen terminal signal processing device provided by the embodiments of the present application can be applied to multi-band screen terminal signal processing of any phase of three-phase electricity, and a multi-band current sensor and a multi-band screen terminal signal processing device can be configured for each phase of electricity. As an example, the multi-band screen terminal sensing signal output by the multi-band current sensor can include a screen terminal sensing signal of a first frequency band, a screen terminal sensing signal of a second frequency band, and a screen terminal sensing signal of a third frequency band. The first frequency band can be a power frequency component (50 Hz), and the screen terminal sensing signal of the first frequency band can be used to monitor leakage current and insulation loss. The second frequency band can be a medium frequency component (20 kHz-200 kHz), and the screen terminal sensing signal of the second frequency band can be used to monitor transient overvoltage, electromagnetic interference, and impact events. The third frequency band can be a high frequency component (200 kHz-5 MHz), and the screen terminal sensing signal of the third frequency band can be used to capture partial discharge and high frequency breakdown signals.

[0053] In some exemplary embodiments, with reference to Figure 1 A multi-band screen terminal signal processing device is provided, which includes a front-end conditioning module 10, a synchronous acquisition module 20, a fusion processing module 30, and a communication module 40.

[0054] The front-end conditioning module 10 is connected with the multi-band current sensor, configured to receive the multi-band screen terminal sensing signal corresponding to the screen terminal of the bushing of the power device output by the multi-band current sensor, and to perform frequency band anti-interference conditioning on the multi-band screen terminal sensing signal, and to output a multi-band screen terminal conditioning signal.

[0055] The screen terminal sensing signal of the first frequency band, the screen terminal sensing signal of the second frequency band, and the screen terminal sensing signal of the third frequency band are output as three signals in a differential form to the front-end conditioning module 10 of the multi-band screen terminal signal processing device, so as to reduce electromagnetic noise interference. The power device is, for example but not limited to, a transformer.

[0056] The synchronous acquisition module 20 is connected with the front-end conditioning module 10, configured to perform synchronous sampling on the multi-band screen terminal conditioning signal based on a unified time reference and a unified phase reference, and to output a multi-band screen terminal sampling signal with a unified timestamp.

[0057] The fusion processing module is connected with the synchronous acquisition module 20, configured to perform time domain alignment, amplitude normalization, phase calibration, feature extraction, and cross-frequency band correlation analysis processing on the multi-band screen terminal sampling signal with the unified timestamp, and to output multi-band fusion data.

[0058] The communication module 40 is connected with the fusion processing module 30, configured to send the multi-band fusion data to a remote analysis module 50. As an example, the communication module 40 can adopt optical fiber communication or Ethernet.

[0059] The scheme of the embodiment of the application is that the anti-interference conditioning of the front-end conditioning module 10 in different frequency bands provides a clean signal basis for subsequent synchronous acquisition and fusion processing, avoiding the intensification of noise interference and judgment errors; the dual-reference synchronization and unified timestamp of the synchronous acquisition module 20 solves the problem of timing deviation; the time domain alignment, amplitude normalization, phase calibration, feature extraction and cross-frequency band correlation analysis processing of the fusion processing module 30 solve the problem of inaccurate fusion, ensuring that multi-frequency band signals can be accurately analyzed in coordination; the communication module 40 transmits the fusion data to a remote analysis device, finally supporting accurate monitoring and evaluation of the state of the power device. In other words, the signal flows from the bushing terminal screen of the power device, is detected by the multi-frequency band current sensor, is conditioned by the front-end conditioning module 10, is sampled by the synchronous acquisition module 20, is fused by the fusion processing module 30, and finally is sent to the remote analysis module 50 of the remote monitoring host through optical fiber communication, so as to realize full-frequency domain state monitoring and abnormality identification.

[0060] In some example embodiments, with reference to Figure 2 The multi-frequency band terminal screen signal processing device further includes a remote analysis module 50. The remote analysis module 50 is configured to receive the multi-frequency band fusion data and determine a state monitoring result of the bushing terminal screen of the power device according to the multi-frequency band fusion data. As an example, the functions of the remote analysis module 50 can include: multi-source signal unpacking and time sequence reconstruction; full-frequency domain feature fusion analysis (such as power frequency imbalance analysis, transient waveform identification, and partial discharge positioning); state evaluation and alarm output; remote clock synchronization (IEEE 1588 (IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems) or PPS (Pulse Per Second)), ensuring long-term synchronization accuracy of the system.

[0061] The scheme of the embodiment of the application is that, by means of multi-source synchronous acquisition, unified clock control and terminal screen signal fusion processing mechanism, unified sampling, synchronous triggering and remote centralized analysis of signals of different frequency bands are realized, and the problem of signal distortion caused by multi-channel asynchronous acquisition is fundamentally solved. The scheme of the embodiment of the application is that, by introducing multi-source synchronous acquisition at the hardware level, the problems of large time synchronization error, inaccurate fusion and poor real-time performance of the multi-frequency band signal acquisition system in the related art are fundamentally solved, full-frequency band, real-time and high-precision fusion monitoring of the terminal screen signal of the bushing of the power device is realized, and reliable data support is provided for state evaluation of the power device in the smart grid.

[0062] In some example embodiments, with reference to Figure 3The synchronous acquisition module 20 comprises a clock source circuit 21, a clock distribution circuit 22, a synchronous trigger circuit 23 and a plurality of analog-to-digital conversion circuits 24.

[0063] The clock source circuit 21 is configured to generate a sampling reference time signal. As an example, the clock source circuit 21 employs an Oven Controlled Crystal Oscillator (OCXO) synchronous clock or a GPS Disciplined Oscillator (GPSDO) to provide a unified sampling reference.

[0064] The clock distribution circuit 22 is connected to the clock source circuit 21 and is configured to generate a unified time reference signal and a unified phase reference signal based on the sampling reference time signal. The clock distribution circuit 22 can comprise a Phase Locked Loop (PLL). The clock distribution circuit 22 can perform phase calibration, frequency tracking and bias-free distribution on the sampling reference time signal, ensuring that the clock signals sent to the plurality of analog-to-digital conversion circuits 24 (ADCs) are completely consistent in phase, thereby achieving synchronous sampling of signals of different frequency bands and eliminating timing errors at the hardware level. The clock distribution circuit 22 performs phase calibration and bias-free distribution on the sampling reference time signal to generate a unified time signal and a unified phase reference signal, and sends them to each analog-to-digital conversion circuit 24 and the synchronous trigger circuit 23.

[0065] The synchronous trigger circuit 23 is connected to the clock distribution circuit 22 and is configured to generate a synchronous trigger pulse based on the unified time reference signal and the unified phase reference signal. As an example, the synchronous trigger circuit 23 can be based on FPGA (Field Programmable Gate Array) synchronous trigger logic, which generates a unified sampling trigger signal to align the sampling edges of each ADC channel, with a time error of ≤10 ns.

[0066] The plurality of analog-to-digital conversion circuits 24 can be understood as a multi-channel ADC array. One analog-to-digital conversion circuit 24 corresponds to one frequency band of the multi-band end screen conditioned signal. For the first, second and third frequency bands of any phase power, three analog-to-digital conversion circuits 24 can be correspondingly arranged. For the first, second and third frequency bands of three-phase power, 3x3=9 analog-to-digital conversion circuits 24 can be correspondingly arranged.

[0067] The analog-to-digital conversion circuit 24 is connected with the front-end processing module 10, the clock distribution circuit 22 and the synchronous trigger circuit 23, and is used for synchronously sampling the end screen processing signal of the target frequency band in the multi-frequency band end screen processing signal based on the unified time reference signal, the unified phase reference signal and the synchronous trigger pulse, and outputting the end screen sampling signal of the target frequency band with a unified time stamp.

[0068] As an example, the plurality of analog-to-digital conversion circuits 24 includes an analog-to-digital conversion circuit 24 of a first frequency band, an analog-to-digital conversion circuit 24 of a second frequency band and an analog-to-digital conversion circuit 24 of a third frequency band; the frequencies of the first frequency band, the second frequency band and the third frequency band increase in turn; and the sampling rates of the analog-to-digital conversion circuit 24 of the first frequency band, the analog-to-digital conversion circuit 24 of the second frequency band and the analog-to-digital conversion circuit 24 of the third frequency band increase in turn.

[0069] As an example, the analog-to-digital conversion circuit 24 of the first frequency band, i.e., the power frequency channel, can adopt a 24-bit Sigma Delta ADC (Sigma Delta analog-to-digital converter) with a sampling rate of 1kS / s. The analog-to-digital conversion circuit 24 of the second frequency band, i.e., the intermediate frequency channel, can adopt a 16-bit Pipeline ADC (pipeline analog-to-digital converter) with a sampling rate of 2MS / s. The analog-to-digital conversion circuit 24 of the third frequency band, i.e., the high frequency channel, adopts a 12-bit high-speed ADC with a sampling rate of 50MS / s-100MS / s.

[0070] In the timing control logic of the embodiment, three types of synchronous signals can be output: a sampling synchronous signal (S-Sync) for simultaneously starting sampling of each ADC; a trigger flag signal (Trig) for marking the starting moment of an event; and a time stamp pulse (Tsync) for FPGA data frame numbering and remote reconstruction. The FPGA realizes pipelining operation of data sampling, fusion, buffering and transmission through an internal timing state machine, with a delay of less than 2ms, and can realize near real-time response.

[0071] In some exemplary embodiments, with reference to Figure 4 The front-end processing module 10 includes an amplification circuit 11, a filtering circuit 12, a gain circuit 13 and a protection circuit 14.

[0072] The amplification circuit 11 is connected with the multi-frequency band current sensor, and is used for amplifying the end screen sensing signal of the target frequency band in the multi-frequency band end screen sensing signal and outputting an amplified signal. The amplification circuit 11 can amplify a weak current signal and improve the signal-to-noise ratio. The target frequency band can be the first frequency band, the second frequency band or the third frequency band. As an example, three amplification circuits 11 can be respectively arranged for the end screen sensing signal of the first frequency band, the end screen sensing signal of the second frequency band and the end screen sensing signal of the third frequency band.

[0073] The filter circuit 12 is connected with the amplification circuit 11, and is used for filtering the amplified signal and outputting a filtered signal. For example, a filter circuit 12 (denoted as filter circuit 121) with a power band pass of 50±5 Hz can be set for the amplified signal of the first frequency band; a filter circuit 12 (denoted as filter circuit 122) with a center frequency band pass of 50 kHz can be set for the amplified signal of the second frequency band; and a filter circuit 12 (denoted as filter circuit 123) with a high frequency band pass of 1 MHz can be set for the amplified signal of the third frequency band; the filter circuit 121, the filter circuit 122 and the filter circuit 123 can be set simultaneously and independently.

[0074] The gain circuit 13 is connected with the filter circuit 12, and is used for amplitude adjusting the filtered signal and outputting an amplitude adjusted signal. The gain circuit 13 keeps the output amplitudes of signals of different frequency bands consistent, so as to avoid ADC saturation.

[0075] The protection circuit 14 is connected with the gain circuit 13, and is used for overvoltage limiting of the amplitude adjusted signal and outputting a final screen signal of a target frequency band. The protection circuit 14 ensures that high frequency interference or lightning transient will not damage the multi-frequency band final screen signal processing device.

[0076] In some exemplary embodiments, the amplification circuit 11 includes a low noise amplifier (LNA). The low noise amplifier is connected with the multi-frequency band current sensor, and is used for amplifying the final screen sensing signal of the target frequency band in the multi-frequency band final screen sensing signal and outputting an amplified signal.

[0077] In some exemplary embodiments, the gain circuit 13 includes an automatic gain control circuit (AGC). The automatic gain control circuit is connected with the filter circuit 12, and is used for amplitude adjusting the filtered signal and outputting an amplitude adjusted signal.

[0078] In some exemplary embodiments, the reference Figure 5 The fusion processing module 30 includes a time domain alignment circuit 31, an amplitude normalization circuit 32, a phase calibration circuit 33, a feature extraction circuit 34 and a cross-frequency band correlation analysis circuit 35.

[0079] The time domain alignment circuit 31 is connected with the synchronous acquisition module 20, and is used for time alignment and interpolation correction (including multi-rate data FIFO buffer (First-In First-Out Buffer) and time stamp matching) of the multi-frequency band final screen sampling signal with a unified time stamp, and outputs a time domain aligned signal. The time domain alignment circuit 31 performs interpolation compensation on data with a sampling time difference less than one sampling period.

[0080] The amplitude normalization circuit 32 is connected with the time domain alignment circuit 31, and is configured to remove amplitude deviation of the time domain aligned signal and output an amplitude normalized signal. The amplitude normalization circuit 32 is configured to unify amplitude ratios of different channels by using a software or hardware lookup table. As an example, the amplitude normalization circuit 32 is configured to convert the time domain aligned signal into a unified physical unit (such as current amplitude mA) or a preset ratio range, eliminate amplitude deviation caused by sensor sensitivity and ADC range difference, and output the amplitude normalized signal.

[0081] The phase calibration circuit 33 is connected with the amplitude normalization circuit 32, and is configured to compensate and correct phase deviation of the amplitude normalized signal and output a phase calibrated signal. The phase calibration circuit 33 is configured to use a phase of a power frequency band signal as a unified reference to compensate and correct the phase deviation of the amplitude normalized signal and output the phase calibrated signal.

[0082] The feature extraction circuit 34 is connected with the phase calibration circuit 33, and is configured to extract key feature parameters of the phase calibrated signal in different frequency bands and output a multi-dimensional feature signal. The feature extraction circuit 34 is configured to calculate root mean square (RMS), crest factor, envelope energy and spectral power in real time. As an example, the feature extraction circuit 34 is configured to extract key feature parameters (RMS and harmonic content in the power frequency band, transient energy and duration in the intermediate frequency band, and partial discharge pulse amplitude and repetition rate in the high frequency band) of the phase calibrated signal in different frequency bands and output the multi-dimensional feature signal.

[0083] The cross-band correlation analysis circuit 35 is connected with the feature extraction circuit 34, and is configured to perform cross-band correlation analysis on the output multi-dimensional feature signal and output multi-band fusion data. If the intermediate frequency signal energy suddenly changes or the high frequency envelope exceeds a set threshold, the transient event or the partial discharge event is automatically marked. As an example, the cross-band correlation analysis circuit 35 is configured to perform cross-band cross-validation and correlation rule mining (including correlation analysis of the power frequency phase and the high frequency partial discharge, and correlation analysis of the intermediate frequency transient and the power frequency harmonic) on the multi-dimensional feature signal and output the multi-band fusion data.

[0084] In some example embodiments, the fusion processing module 30 includes a field programmable gate array circuit. The FPGA is internally provided with a plurality of FIFO buffer areas and a time stamp generation unit, which are configured to perform time domain alignment on data of different rate channels. The fusion result is cached at the end of the screen, and is packaged into a fusion signal frame with a unified time stamp and sent to the communication module 40.

[0085] As an example, a signal fusion algorithm based on time domain weighted average is used in the FPGA: different frequency band signals are mapped to a unified time axis; for the power frequency, intermediate frequency and high frequency signals in the same time window, a weight Weighted fusion is performed (with frequency band bandwidth adjustment), Bi refers to three frequency bands of power frequency, intermediate frequency and high frequency, each having a weight coefficient Wi; output signal features include:

[0086] Synthesized energy: ;

[0087] Peak time: ;

[0088] Mutation threshold trigger flag: .

[0089] When = 1, the system generates an event frame and sends it to the upper computer.

[0090] This method can simultaneously retain power frequency waveform information and high frequency mutation characteristics, and realize single-point detection and multi-dimensional fusion.

[0091] The following takes a 110kV transformer bushing as an example to exemplarily and supplementarily describe the technical scheme of the embodiment of the application:

[0092] The multi-band current sensor is installed at the end shield of the bushing, and three signals are led out, which are collected and fused by the technical scheme of the embodiment of the application.

[0093] The configuration parameters are as shown in Table One:

[0094] Table One

[0095]

[0096] The working process is as follows: multi-band current signal input device; after each frequency band signal is filtered and amplified, it is sent to the respective ADC; the FPGA generates a unified sampling trigger signal, and each ADC samples simultaneously; the FPGA internally performs interpolation, synchronization and amplitude correction on the three channel data; the data is fused into a unified format frame, and after adding a time stamp, it is cached; the data is transmitted to the remote monitoring host computer through the optical fiber interface.

[0097] In actual testing, the multi-band end shield signal processing device realizes a power frequency and high frequency signal synchronization deviation of <8ns, and the phase of the partial discharge event and transient signal peak value detected after multi-source fusion is consistent, with an error of less than 0.5°, proving that the synchronization acquisition and fusion precision of the multi-band end shield signal processing device meets the requirements of power monitoring applications.

[0098] The scheme of the embodiment of the application includes: a multi-source synchronous acquisition overall structure: a system structure integrating multi-band current sensing, signal conditioning, multi-channel synchronous acquisition, signal fusion and remote communication is integrated at the end shield of the transformer bushing. Unified clock and synchronous sampling mechanism: a unified clock source and clock distribution network are used to enable the power frequency, intermediate frequency and high frequency channels to be synchronously sampled under the same time base, with a sampling time difference controlled at the nanosecond level.

[0099] FPGA end time alignment and multi-source fusion processing: data caching, interpolation time alignment, amplitude normalization, feature extraction and event triggering are realized in the FPGA inside the end screen to generate a unified timestamp fusion signal frame.

[0100] Front-end signal conditioning and anti-interference circuit: independent amplification, filtering, automatic gain and amplitude limiting protection circuit 14 are designed for different frequency bands to realize high signal-to-noise ratio acquisition. Remote centralized processing and communication interface: transmit the fusion signal through the optical fiber or Ethernet interface to realize remote centralized diagnosis and clock synchronization.

[0101] The technical effects of the embodiments of the present application include: high synchronization accuracy: due to the use of a unified clock source and synchronous triggering, the time alignment accuracy of three frequency band signals is improved to the nanosecond level, eliminating the time delay error of traditional multi-channel asynchronous sampling. Real-time fusion and fast response: the FPGA at the end of the screen directly completes time alignment and fusion, reducing remote processing delay, realizing real-time event recognition and partial discharge detection. Small communication data volume and high efficiency: local feature extraction and event triggering, only upload the fusion signal frame, the communication bandwidth demand is reduced by about 70%. Strong anti-interference: differential input, shielding wiring and filter protection design significantly improve the signal stability in strong electromagnetic environment. Compact structure, easy engineering: high module integration, small size, low power consumption, suitable for long-term installation on the end screen of the transformer bushing for online monitoring.

[0102] Based on the same inventive concept, in some exemplary embodiments, the embodiments of the present application also provide a bushing end screen monitoring device, which comprises a multi-band current sensor and a multi-band end screen signal processing device provided by any of the above embodiments. The multi-band current sensor is installed on the end screen of the bushing. The multi-band end screen signal processing device is connected with the multi-band current sensor.

[0103] The bushing end screen monitoring device and the multi-band end screen signal processing device provided by the embodiments of the present application belong to the same inventive concept, can solve the same technical problems, and then achieve the same technical effects, and the repeated contents will not be described here.

[0104] Based on the same inventive concept, in some exemplary embodiments, the embodiments of the present application also provide a power system, which comprises a transformer and a bushing end screen monitoring device provided by any of the above embodiments. The multi-band current sensor is installed on the end screen of the bushing of the transformer.

[0105] The power system and the multi-band end screen signal processing device provided by the embodiments of the present application belong to the same inventive concept, can solve the same technical problems, and then achieve the same technical effects, and the repeated contents will not be described here.

[0106] In the description of the specification, the description of the terms "some embodiments", "other embodiments", etc. means that the particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The illustrative examples of the application described above are not meant to be comprehensive and exhaustive, but rather to provide examples of the application. Thus, the above description is not meant to limit the scope of the application.

[0107] The technical features of the above-described embodiments can be combined in any manner, and for brevity, not all possible combinations of the technical features are described in the specification, but it should be understood that any combination of the technical features that does not cause a contradiction is within the scope of the present application.

[0108] The above-described embodiments only express several implementation manners of the application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the application. It should be pointed out that for those skilled in the art, some modifications and improvements can be made without departing from the concept of the application, and these are within the protection scope of the application. Therefore, the protection scope of the application should be subject to the appended claims.

Claims

1. A multi-band end-screen signal processing device, characterized in that, The device includes: The front-end conditioning module is connected to the multi-band current sensor and is used to receive the multi-band end screen sensing signal of the corresponding power device bushing end screen output by the multi-band current sensor, and to perform frequency-band anti-interference conditioning on the multi-band end screen sensing signal and output the multi-band end screen conditioning signal. The synchronous acquisition module is connected to the front-end conditioning module and is used to synchronously sample the multi-band end-screen conditioning signal based on a unified time reference and a unified phase reference, and output a multi-band end-screen sampling signal with a unified timestamp. The fusion processing module, connected to the synchronous acquisition module, is used to perform time-domain alignment, amplitude normalization, phase calibration, feature extraction, and cross-frequency band correlation analysis on the multi-band end-screen sampling signal with a unified timestamp, and output multi-frequency band fusion data. A communication module, connected to the fusion processing module, is used to send the multi-band fused data to the remote analysis module.

2. The apparatus according to claim 1, characterized in that, The synchronous acquisition module includes: Clock source circuit, used to generate sampling reference time signal; A clock distribution circuit, connected to the clock source circuit, is used to generate a unified time reference signal and a unified phase reference signal based on the sampling reference time signal; A synchronous triggering circuit, connected to the clock distribution circuit, is used to generate synchronous triggering pulses based on the unified time reference signal and the unified phase reference signal; Multiple analog-to-digital conversion circuits are provided, one of which corresponds to a frequency band of the multi-band end-screen conditioning signal. The analog-to-digital conversion circuit is connected to the front-end conditioning module, the clock distribution circuit, and the synchronization trigger circuit. It is used to synchronously sample the end-screen conditioning signal of the target frequency band in the multi-band end-screen conditioning signal based on the unified time reference signal, the unified phase reference signal, and the synchronization trigger pulse, and output the end-screen sampling signal of the target frequency band with a unified timestamp.

3. The apparatus according to claim 2, characterized in that, The plurality of analog-to-digital conversion circuits include an analog-to-digital conversion circuit for a first frequency band, an analog-to-digital conversion circuit for a second frequency band, and an analog-to-digital conversion circuit for a third frequency band; The frequencies of the first frequency band, the second frequency band, and the third frequency band increase sequentially. The sampling rates of the analog-to-digital converter circuits in the first frequency band, the second frequency band, and the third frequency band increase sequentially.

4. The apparatus according to claim 1, characterized in that, The front-end conditioning module includes: An amplifier circuit, connected to the multi-band current sensor, is used to amplify the target frequency band end-screen sensing signal in the multi-band end-screen sensing signal and output the amplified signal. A filtering circuit, connected to the amplification circuit, is used to filter the amplified signal and output a filtered signal. A gain circuit, connected to the filter circuit, is used to adjust the amplitude of the filtered signal and output the amplitude-adjusted signal. A protection circuit, connected to the gain circuit, is used to perform overvoltage limiting processing on the amplitude-adjusted signal and output the final screen conditioning signal of the target frequency band.

5. The apparatus according to claim 4, characterized in that, The amplification circuit includes a low-noise amplifier; the low-noise amplifier is connected to the multi-band current sensor and is used to amplify the target frequency band end-screen sensing signal in the multi-band end-screen sensing signal and output the amplified signal. The gain circuit includes an automatic gain control circuit; the automatic gain control circuit is connected to the filter circuit and is used to adjust the amplitude of the filtered signal and output the amplitude-adjusted signal.

6. The apparatus according to claim 1, characterized in that, The fusion processing module includes: A time-domain alignment circuit, connected to the synchronous acquisition module, is used to perform time alignment and interpolation correction on the multi-band end-screen sampling signal with a unified timestamp, and output the time-domain aligned signal. An amplitude normalization circuit, connected to the time-domain alignment circuit, is used to remove amplitude deviation from the time-domain aligned signal and output an amplitude-normalized signal. A phase calibration circuit, connected to the amplitude normalization circuit, is used to compensate and correct the phase deviation of the amplitude normalized signal and output a phase-calibrated signal. The feature extraction circuit, connected to the phase calibration circuit, is used to extract key feature parameters from the phase-calibrated signal by frequency band and output multi-dimensional feature signals. A cross-band correlation analysis circuit, connected to the feature extraction circuit, is used to perform cross-band correlation analysis on the output multi-dimensional feature signal and output the multi-band fused data.

7. The apparatus according to claim 1, characterized in that, The fusion processing module includes a field-programmable gate array (FPGA) circuit.

8. The apparatus according to claim 1, characterized in that, The device further includes: The remote analysis module is used to receive the multi-band fusion data and determine the status monitoring results of the power device bushing end screen based on the multi-band fusion data.

9. A casing end-screen monitoring device, characterized in that, It includes a multi-band current sensor and a multi-band end-screen signal processing device as described in any one of claims 1-8; the multi-band current sensor is installed on the end screen of the bushing; the multi-band end-screen signal processing device is connected to the multi-band current sensor.

10. An electric power system, characterized in that, The system includes a transformer and a bushing end screen monitoring device as described in claim 9; the multi-band current sensor is installed on the bushing end screen of the transformer.

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