A non-contact broadband voltage monitoring system

Abstract

The present application relates to the technical field of voltage monitoring, and provides a non-contact broadband voltage monitoring system. The system includes a laser source, a receiving module, an acquisition module, a communication module and an analysis module, the output signal of the coaxial cable laser source is connected to the input of the TEM chamber, a micro photoelectric sensing device is provided in the acquisition module, a sensing central processor is provided in the sensing device, the input signal of the sensing central processor is connected to the output of the laser source, and the output of the sensing central processor is linearly connected to the input of the communication module, so as to realize real-time early warning based on electromagnetic process analysis, obtain information on the precursor of line faults from a large amount of operation monitoring status data, compare and analyze the differences in the characteristics of the traveling waves of the transmission line during various faults, effectively identify the type of transmission line faults, and realize fault location.

Description

Technical Field

[0001] The present application relates to the technical field of voltage monitoring, and in particular to a non-contact broadband voltage monitoring system. Background Art

[0002] In modern power supply systems, overvoltage occurs from time to time. Lightning strikes, faults, resonance, and operation may all cause overvoltage in the power grid. Once an electrical device in operation encounters overvoltage, it may cause discharge, flashover, breakdown, explosion, and other accidents. Therefore, monitoring and analysis of overvoltage in the power system is extremely important.

[0003] However, the fault location of power grid currently relies only on fault current signal, lacking fault voltage signal. When judging non-lightning faults such as tree obstacles, the positioning accuracy is not high. The reliability of substation overvoltage monitoring system, the systematicness of data accumulation, and the scientificity of data processing are relatively lacking. The measured data of transient voltage of substation is still not systematic enough. This bottleneck restricts the fault analysis of power system. Summary of the invention

[0004] The present application discloses a non-contact broadband voltage monitoring system to solve the technical problems in the prior art that power grid fault location currently relies only on fault current signals and lacks fault voltage signals, and the positioning accuracy is not high when judging non-lightning faults such as tree obstacles, and the reliability of the substation overvoltage monitoring system, the systematic nature of data accumulation, and the scientific nature of data processing are relatively lacking, and the measured data of the substation transient voltage is still not systematic enough.

[0005] The first aspect of the present application discloses a non-contact broadband voltage monitoring system, comprising: a laser source, a receiving module, a collection module, a communication module and an analysis module;

[0006] The laser source is connected to the acquisition module via a coaxial cable, the output signal of the laser source is connected to the input of the TEM cell, and the output of the TEM cell is connected to the acquisition module, so as to generate a uniformly distributed electric field;

[0007] The acquisition module is connected to the receiving module, monitors the voltage signal in real time, acquires the voltage signal, digitizes the voltage signal, and determines whether to trigger the storage data and cache mechanism; the acquisition module is provided with a micro photoelectric sensing device, and the micro photoelectric sensing device is provided with a perception central processor, the input end signal of the perception central processor is connected to the output end of the laser source, and the output end of the perception central processor is linearly connected to the input end of the communication module, and the perception central processor includes an acquisition card and a high-speed FPGA chip, the acquisition card is used for signal acquisition and digital processing, and the high-speed FPGA chip is used to determine whether to trigger the storage data and cache mechanism to save the signal;

[0008] The communication module is connected to the acquisition module and the receiving module respectively, and is used for signal transmission;

[0009] The receiving module is connected to the acquisition module and is used for receiving signals. The receiving module includes a power amplifier, a bidirectional power coupler, a power meter, a power load and a spectrum analyzer;

[0010] Analysis module, used for analysis and location of transmission line faults.

[0011] Optionally, the micro photoelectric sensing device uses integrated optical technology to etch waveguides on the crystal and lay electrodes of specific shapes to form a wide-band, miniaturized sensing device.

[0012] Optionally, the micro photoelectric sensing device also includes different waveguide topologies and widths, and the output static operating point of the micro photoelectric sensing device is measured to obtain the optimal structure.

[0013] Optionally, the acquisition module acquires the voltage signal by shortening the fault section and wave velocity dynamics to online measure the positioning error caused by inaccurate given line length, attenuation and distortion of traveling wave signals, and uncertainty of wave velocity.

[0014] Optionally, the non-contact broadband voltage monitoring system also includes studying the mathematical relationship between the changes in distributed parameters caused by temperature and humidity and the measurement results of the micro-photoelectric sensing device, improving the optical path and dual optical path interference compensation method of the micro-photoelectric sensing device, and improving its temperature stability from a structural perspective.

[0015] Optionally, the analysis module adopts a method combining fast intrinsic mode decomposition and energy operator to detect the arrival time of the initial traveling wave of the fault. Through the study and analysis of the real recorded data extracted from the fault site, the external meteorological factors and internal factors of the fault are deeply explored according to different cause types, and the characteristic laws of weather, season, time, reclosing, DC content of fault phase current, third harmonic content, zero-crossing distortion and transition resistance properties are summarized, and the importance of the features is evaluated and ranked using score indicators.

[0016] Optionally, the analysis module also includes integrating external meteorological characteristics and internal characteristics obtained from recording, using support vector machines (SVM) to establish a nonlinear correspondence between fault characteristics and categories to identify fault causes, and using a particle swarm algorithm (PSO) to optimize the parameters of the model, while considering sample imbalance problems and the algorithm's self-learning ability in the algorithm.

[0017] The second aspect of the present application discloses a non-contact broadband voltage monitoring method, comprising:

[0018] Construct a measurement system with an optoelectronic integrated sensor as the core sensor element, use the linearly polarized light generated by a laser source to enter the optoelectronic integrated sensor through a polarization-maintaining optical fiber, the linearly polarized light transmitted in the optical waveguide receives phase modulation of the electric field to be measured, and the polarized light carrying the phase information is converted into a light intensity signal after interference, and then transmitted to the optical detector through a single-mode optical fiber to be converted into an electrical signal reflecting the magnitude of the electric field to be measured;

[0019] Establish a calibration system consisting of a laser source, power amplifier, bidirectional power coupler, power meter, TEM chamber, power load and spectrum analyzer, and obtain the time-frequency characteristics of the electrical signal by measuring the output of the micro-photoelectric sensing device;

[0020] Through the study and analysis of the real recorded data extracted from the fault site, the external meteorological factors and internal factors of the fault are deeply explored according to different cause types, and the characteristic laws of weather, season, time, reclosing, DC content of fault phase current, third harmonic content, zero-crossing distortion and transition resistance properties are summarized, and the importance of the features is evaluated and ranked using score indicators.

[0021] The present application provides a non-contact broadband voltage monitoring system. Through the above technical solution, the beneficial effects of the present application are:

[0022] This application conducts transient voltage parameter monitoring of transmission lines based on advanced sensing technology, adopts theoretical research combined with data analysis methods, fully mines existing historical data, studies the characteristics and evaluation methods of system failures, realizes real-time early warning based on electromagnetic process analysis, obtains information on line failure precursors from a large amount of operation monitoring status data, conducts comparative analysis on the differences in transmission line traveling wave characteristics during various failures, effectively identifies transmission line failures, and realizes fault location. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] Figure 1 A schematic diagram of the structure of a non-contact broadband voltage monitoring system provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of an analysis module in a non-contact broadband voltage monitoring system provided in an embodiment of the present application;

[0026] Figure 3 A hardware topology connection diagram of a non-contact broadband voltage monitoring system provided in an embodiment of the present application in practical application;

[0027] Figure 4 A schematic diagram of the structure of a measurement system with an optoelectronic integrated sensor as the core sensing element provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] See also Figure 1 The first embodiment of the present application provides a non-contact broadband voltage monitoring system, including a laser source, a receiving module, a collection module and a communication module.

[0031] The laser source is connected to the acquisition module through a coaxial cable, the output signal of the laser source is connected to the input of the TEM cell, and the output of the TEM cell is connected to the acquisition module to generate a uniformly distributed electric field.

[0032] The acquisition module is connected to the receiving module, monitors the voltage signal in real time, acquires the voltage signal, digitizes the voltage signal, and determines whether to trigger the storage data and cache mechanism. The acquisition module is provided with a micro photoelectric sensing device, and the micro photoelectric sensing device is provided with a sensing central processor. The input signal of the sensing central processor is connected to the output of the laser source, and the output of the sensing central processor is linearly connected to the input of the communication module. The sensing central processor includes an acquisition card and a high-speed FPGA chip. The acquisition card is used for signal acquisition and digital processing, and the high-speed FPGA chip is used to determine whether to trigger the storage data and cache mechanism to save the signal.

[0033] The communication module is connected to the acquisition module and the receiving module respectively for signal transmission.

[0034] The receiving module is connected to the acquisition module and is used for receiving signals. The receiving module includes a power amplifier, a bidirectional power coupler, a power meter, a power load and a spectrum analyzer.

[0035] Analysis module, used for analysis and location of transmission line faults.

[0036] The TEM chamber is a metal enclosure, which is mainly used for radio frequency electromagnetic field radiation immunity test and radio frequency electromagnetic field emission measurement of electronic equipment. The voltage of the inner and outer conductors can vary from a few microvolts to hundreds of volts.

[0037] In some embodiments of this application, the micro photoelectric sensing device uses integrated optical technology to etch waveguides on the crystal and lay electrodes of specific shapes to form a broadband, miniaturized sensing device. This includes different waveguide topologies and widths, and measures the static operating point of the sensing device output to obtain the optimal structure.

[0038] The spatial low-frequency device performs charge simulation on charge induction and calculates the effective value of the induced voltage through dynamic analysis of the vibration unit.

[0039] In some embodiments of the present application, the acquisition module acquires the voltage signal by shortening the fault section and the dynamics of the wave speed, and online measures the positioning error caused by the inaccurate length of a given line, the attenuation and distortion of the traveling wave signal, and the uncertainty of the wave speed.

[0040] In some embodiments of the present application, the non-contact broadband voltage monitoring system also includes studying the mathematical relationship between the distribution parameter changes caused by temperature and humidity and the measurement results of the micro-photoelectric sensing device, and improving its temperature stability from a structural perspective by improving the optical path of the micro-photoelectric sensing device, dual optical path interference compensation, etc. In a temperature control box, a static operating point test under temperature control conditions is carried out to study the temperature compensation method. The influence mechanism of temperature and humidity on the measurement results of the sensing device is studied.

[0041] See also Figure 2 This application studies the use of micro-photoelectric sensing equipment to achieve inductive grid state perception based on electric field strength inversion, analyzes its establishment conditions and scope of application, analyzes the source of errors, and methods to reduce perception deviations, studies the mutual coupling mechanism of spatial electric and magnetic fields in a multi-conductor environment, and provides a decoupling technology for grid parameter measurement waveforms in a multi-conductor environment.

[0042] In some embodiments of the present application, in response to the problems existing in the currently commonly used traveling wave head detection algorithms, wavelet transform and Hilbert-Huang transform, the present application adopts a combination of fast intrinsic mode decomposition and energy operator to detect the arrival time of the initial traveling wave of the fault. Through the study and analysis of the real recorded data extracted from the fault site, the external meteorological factors and internal factors of the fault are deeply explored according to different cause types, and the characteristic laws of weather, season, time, reclosing, DC content of fault phase current, third harmonic content, zero-crossing distortion and transition resistance properties are summarized, and the importance of the features is evaluated and ranked using score indicators.

[0043] In some embodiments of the present application, the analysis module also includes integrating external meteorological characteristics and internal characteristics obtained by recording, using a support vector machine (SVM) that has unique advantages for small sample data to establish a nonlinear correspondence between fault characteristics and categories, and realizing fault cause identification, and using a particle swarm algorithm (PSO) to optimize the parameters of the model, while considering the sample imbalance problem and the algorithm's self-learning ability in the algorithm.

[0044] The core of the perception system is the miniature photoelectric perception device. The perception system monitors the voltage signal in real time, digitizes the signal through a high-speed acquisition card, and uses the high-speed FPGA chip integrated in the system to determine whether a trigger is needed and start storing data. The caching mechanism is used to save the digitally collected signal in the system for an appropriate time for the communication system to process.

[0045] It can be seen from the above technical scheme that a non-contact broadband voltage monitoring system disclosed in the present application includes a laser source, a receiving module, an acquisition module, a communication module and an analysis module. The signal at the output end of the coaxial cable laser source is connected to the input end of the TEM chamber. A miniature photoelectric sensing device is arranged in the acquisition module. A sensing central processor is arranged in the sensing device. The input end signal of the sensing central processor is connected to the output end of the laser source, and the output end of the sensing central processor is linearly connected to the input end of the communication module, so as to realize real-time early warning based on electromagnetic process analysis.

[0046] In practical applications, see Figure 3 The non-contact broadband voltage monitoring system is connected to the AC 220V interface through a cable. The acquisition module in the non-contact broadband voltage monitoring system is connected to the photoelectric integrated sensor through a polarization-maintaining optical fiber, and is used to use the linearly polarized light generated by the laser source to enter the photoelectric integrated sensor through the polarization-maintaining optical fiber. The non-contact broadband voltage monitoring system is connected to the monitoring workstation in the background through a wireless network.

[0047] The polarization-maintaining optical fiber is a special optical fiber that can ensure that the linear polarization direction remains unchanged and improve the coherent signal-to-noise ratio to achieve high-precision measurement of physical quantities. A sensor bracket is provided below the optoelectronic integrated sensor to ensure the stability of the optoelectronic integrated sensor. The present application obtains information on the precursors of line faults from a large amount of operation monitoring status data, compares and analyzes the differences in the characteristics of the transmission line travel waves during various faults, effectively identifies the type of transmission line faults, and realizes fault location.

[0048] The second embodiment of the present application discloses a non-contact broadband voltage monitoring method. For details not disclosed in the method embodiment of the present application, please refer to the system embodiment of the present application, including:

[0049] See also Figure 4, the present embodiment provides a schematic diagram of the structure of a measurement system with a photoelectric integrated sensor as the core sensor element. The present embodiment adopts integrated optical technology and constructs a measurement system with a photoelectric integrated sensor as the core sensor element by improving the sensor optical path, dual optical path interference compensation and other means. The linearly polarized light generated by a laser source is incident on the photoelectric integrated sensor through a polarization-maintaining optical fiber. The linearly polarized light transmitted in the optical waveguide receives phase modulation of the electric field to be measured. The polarized light carrying the phase information is converted into a light intensity signal after interference, and then transmitted to the optical detector through a single-mode optical fiber and converted into an electrical signal. The electrical signal reflects the size of the electric field to be measured.

[0050] A calibration system consisting of a laser source, a power amplifier, a bidirectional power coupler, a power meter, a TEM chamber, a power load and a spectrum analyzer is established. In the TEM chamber, the power signal is input into the TEM chamber through a coaxial cable to obtain a uniformly distributed electric field; the time-frequency characteristics of the electrical signal are obtained by measuring the output of the micro-photoelectric sensing device;

[0051] Through the study and analysis of the real recorded data extracted from the fault site, the external meteorological factors and internal factors of the fault are deeply explored according to different cause types, and the characteristic laws of weather, season, time, reclosing, DC content of fault phase current, third harmonic content, zero-crossing distortion and transition resistance properties are summarized, and the importance of the features is evaluated and ranked using score indicators.

[0052] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0056] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A non-contact broadband voltage monitoring system, characterized in that: include: Laser source, receiving module, acquisition module, communication module and analysis module; The laser source is connected to the acquisition module via a coaxial cable, the output signal of the laser source is connected to the input of the TEM cell, and the output of the TEM cell is connected to the acquisition module, so as to generate a uniformly distributed electric field; The acquisition module is connected to the receiving module, monitors the voltage signal in real time, acquires the voltage signal, digitizes the voltage signal, and determines whether to trigger the storage data and cache mechanism; the acquisition module is provided with a micro photoelectric sensing device, and the micro photoelectric sensing device is provided with a perception central processor, the input end signal of the perception central processor is connected to the output end of the laser source, and the output end of the perception central processor is linearly connected to the input end of the communication module, and the perception central processor includes an acquisition card and a high-speed FPGA chip, the acquisition card is used for signal acquisition and digital processing, and the high-speed FPGA chip is used to determine whether to trigger the storage data and cache mechanism to save the signal; The communication module is connected to the acquisition module and the receiving module respectively, and is used for signal transmission; The receiving module is connected to the acquisition module and is used for receiving signals. The receiving module includes a power amplifier, a bidirectional power coupler, a power meter, a power load and a spectrum analyzer; Analysis module, used for analysis and location of transmission line faults; The non-contact broadband voltage monitoring system also includes studying the mathematical relationship between the distribution parameter changes caused by temperature and humidity and the measurement results of the micro photoelectric sensing device, improving the optical path and dual optical path interference compensation method of the micro photoelectric sensing device, and improving its temperature stability from a structural perspective; The analysis module uses a method combining fast intrinsic mode decomposition and energy operator to detect the arrival time of the initial traveling wave of the fault. Through the research and analysis of the real recorded data extracted from the fault site, the external meteorological factors and internal factors of the fault are deeply explored according to different cause types, and the characteristic laws of weather, season, time, reclosing, DC content of fault phase current, third harmonic content, zero-crossing distortion and transition resistance properties are summarized, and the importance of the features is evaluated and ranked using score indicators; The analysis module also includes integrating external meteorological features and internal features obtained by recording, using support vector machine SVM to establish a nonlinear correspondence between fault features and categories to identify fault causes, using particle swarm algorithm PSO to optimize model parameters, and considering sample imbalance and algorithm self-learning ability in the algorithm; Micro-photoelectric sensing equipment is used to realize inductive grid status perception based on electric field strength inversion. The conditions and scope of application of the perception are analyzed, as well as the sources of errors and methods to reduce perception deviations. The mutual coupling mechanism of spatial electric and magnetic fields in a multi-conductor environment is studied, and the decoupling technology of grid parameter measurement waveforms in a multi-conductor environment is given.

2. The non-contact broadband voltage monitoring system according to claim 1, characterized in that: The micro photoelectric sensing device also includes different waveguide topological structures and widths. The output static working point of the micro photoelectric sensing device is measured to obtain the optimal structure.

3. The non-contact broadband voltage monitoring system according to claim 1, characterized in that: The acquisition module acquires the voltage signal by shortening the fault section and wave velocity dynamics to online measure the positioning error caused by the inaccurate length of the given line, the attenuation and distortion of the traveling wave signal and the uncertainty of the wave velocity.

4. A non-contact broadband voltage monitoring method, applied to the non-contact broadband voltage monitoring system as claimed in any one of claims 1 to 3, characterized in that: include: Construct a measurement system with an optoelectronic integrated sensor as the core sensor element, use the linear polarized light generated by a laser source to enter the optoelectronic integrated sensor through an optical fiber, the linear polarized light transmitted in the optical waveguide receives phase modulation of the electric field to be measured, and the polarized light carrying the phase information is converted into a light intensity signal after interference, and then transmitted to the optical detector through a single-mode optical fiber to be converted into an electrical signal reflecting the magnitude of the electric field to be measured; Establish a calibration system consisting of a laser source, power amplifier, bidirectional power coupler, power meter, TEM chamber, power load and spectrum analyzer, and obtain the time-frequency characteristics of the electrical signal by measuring the output of the micro-photoelectric sensing device; Through the study and analysis of the real recorded data extracted from the fault site, the external meteorological factors and internal factors of the fault are deeply explored according to different cause types, and the characteristic laws of weather, season, time, reclosing, DC content of fault phase current, third harmonic content, zero-crossing distortion and transition resistance properties are summarized, and the importance of the features is evaluated and ranked using score indicators.

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