CN111024376B - System and method for detecting defects of electrical equipment by using sweep frequency impact current - Google Patents
System and method for detecting defects of electrical equipment by using sweep frequency impact current Download PDFInfo
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- CN111024376B CN111024376B CN201911179525.5A CN201911179525A CN111024376B CN 111024376 B CN111024376 B CN 111024376B CN 201911179525 A CN201911179525 A CN 201911179525A CN 111024376 B CN111024376 B CN 111024376B
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- 238000000034 method Methods 0.000 title claims abstract description 23
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- 238000010183 spectrum analysis Methods 0.000 claims abstract description 6
- 238000004458 analytical method Methods 0.000 claims description 7
- 238000001228 spectrum Methods 0.000 claims description 7
- 238000007621 cluster analysis Methods 0.000 claims description 4
- 238000005259 measurement Methods 0.000 claims description 3
- 230000010355 oscillation Effects 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 claims description 3
- 230000001939 inductive effect Effects 0.000 claims description 2
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- 238000004590 computer program Methods 0.000 description 7
- 230000004044 response Effects 0.000 description 5
- 230000006870 function Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H11/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties
- G01H11/06—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties by electric means
- G01H11/08—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties by electric means using piezoelectric devices
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Abstract
The invention discloses a system for detecting defects of electrical equipment by utilizing sweep frequency impulse current, which comprises an impulse current generator, an adjustable inductor, a vibration sensor, a data acquisition device and a vibration test system, wherein the impulse current generator is connected with the vibration sensor; the impulse current generator is connected with the adjustable inductor in series and then is connected with one end of the electrical equipment; the vibration sensor is arranged on the outer surface of the electrical equipment and is connected to the vibration testing system through the data acquisition device; the vibration testing system carries out frequency spectrum analysis on the vibration signals and identifies the types of mechanical defects of the electrical equipment. The invention judges and identifies the mechanical fault type of the equipment by detecting and analyzing the vibration signal under the sweep frequency impact current, and can detect the internal mechanical defects of the electrical equipment. The invention also discloses a method for detecting the defects of the electrical equipment by utilizing the sweep frequency impulse current.
Description
Technical Field
The invention relates to a defect detection technology of electrical equipment, in particular to a system and a method for detecting defects of electrical equipment by utilizing sweep frequency impact current.
Background
The normal operation of electrical equipment is critical to the stability of the overall power system, and therefore, the detection and identification of defects in electrical equipment becomes the basis for maintaining the stability of the power system. Among numerous electrical equipment defects, mechanical structure defects have certain concealment, and electrical faults can be caused if the defects are not processed in time, so that the normal operation of the equipment is influenced, and power failure accidents are caused. The defects of the mechanical structure of the electrical equipment are difficult to timely and effectively find and identify by the conventional electrical detection method, most of the existing mature defect detection methods and devices aim at the insulation and heating defects of the electrical equipment, and the devices and methods for detecting the defects of the mechanical structure are fewer.
The invention discloses a system and a method for detecting the state of a transformer winding by exciting with a constant-current frequency-sweeping power supply, which are disclosed in Chinese patent specification CN 101738567A.
However, the above method has the following problems: firstly, the system inputs steady-state alternating current, can generate larger alternating electromagnetic force aiming at a transformer winding so as to cause vibration, but cannot cause effective vibration response to other non-winding electrical equipment, so that the applicability is narrower. Secondly, the system identifies defects by detecting the steady-state vibration response of the transformer under a certain frequency excitation signal, the frequency spectrum coverage range is limited, the detection time is long, and abundant mechanical structure response information cannot be timely and effectively acquired.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a system and a method for detecting defects of electrical equipment by using sweep frequency impact current, which are high in detection efficiency by judging and identifying the mechanical fault type of the equipment through detection and analysis of vibration signals under the sweep frequency impact current.
The technical scheme is as follows: the invention discloses a system for detecting defects of electrical equipment by utilizing sweep frequency impact current, which comprises an impact current generator, an adjustable inductor, a vibration sensor, a data acquisition device and a vibration test system, wherein the impact current generator is connected with the adjustable inductor; the impulse current generator is connected with the adjustable inductor in series and then is connected with one end of the electrical equipment; the vibration sensor is arranged on the outer surface of the electrical equipment and is connected to the vibration testing system through the data acquisition device; and the vibration testing system (5) performs frequency spectrum analysis on the vibration signals and identifies the types of mechanical defects of the electrical equipment.
The device also comprises a current divider and an oscilloscope, wherein the impulse current generator is connected with the oscilloscope through the current divider so as to detect the waveform of the impulse current.
The peak value of the output current of the impact current generator is not lower than 80kA, and the energy is not lower than 15 kJ.
The adjustable inductor adopts a coreless coil type, and the coreless coil type can avoid iron core saturation under the condition of large current.
The sensitivity of the vibration sensor is 80-200 mV/g, the measurement range is 5-80g, and the central frequency range covers 0.1-30000 Hz.
The data acquisition device is a data acquisition card which simultaneously acquires more than 4 groups of sensor data to realize multipoint vibration signal analysis of the equipment.
A method for detecting defects of electrical equipment by utilizing sweep frequency impact current comprises the following steps:
(a) the inductive reactance of the adjustable inductor is adjusted, so that the oscillation center frequency of the surge current waveform is changed to a proper value;
(b) charging the impulse current generator to a preset voltage, triggering the impulse current generator, and applying the generated impulse current to the electrical equipment;
(c) the vibration sensor collects vibration signals on the surface of the electrical equipment, and a frequency spectrogram is formed after the vibration signals are converted by the vibration testing system;
(d) the vibration test system analyzes the spectrogram and identifies whether the electrical equipment has mechanical structure defects.
In the step (d), the vibration testing system performs characteristic analysis on the spectrogram by using an entropy spectrum method and a cluster analysis method, and identifies the category of the mechanical defect of the electrical equipment.
Has the advantages that: compared with the prior art, the invention has the beneficial effects that: (1) the mechanical fault type of the equipment is judged and identified through detection and analysis of vibration signals under the sweep frequency impact current, and the internal mechanical defects of the electrical equipment can be detected; (2) the non-invasive diagnosis of the defects of the internal mechanical structure of the electrical equipment is realized, the defect detection efficiency is improved, and the maintenance cost of the electrical equipment is saved.
Drawings
FIG. 1 is a schematic structural diagram of a system for detecting defects of electrical equipment by using swept-frequency impulse current according to the present invention.
Detailed Description
The invention will be described in further detail below with reference to specific embodiments and the attached drawings.
As shown in fig. 1, the system of the invention comprises an impact current generator 1, an adjustable inductor 2, a vibration sensor 3, a data acquisition device 4, a vibration test system 5, a shunt 6 and an oscilloscope 7, wherein the output end of the impact current generator 1 is connected with the adjustable inductor 2 in series and then is connected with one end of an electrical device 8 to be tested, and the impact current generator 1, the adjustable inductor 2 and the electrical device 8 are connected in series to form a loop through a copper wire; the impulse current generator 1 is connected with the electrical equipment 8 in a grounding way; the impulse current generator 1 is connected with an oscilloscope 7 through a shunt 6 to realize the monitoring of the discharge current waveform. In the embodiment, the peak value of the output current of the impact current generator 1 is not lower than 80kA, and the energy is not lower than 15 kJ.
One end of the adjustable inductor 2 is connected with the output end of the impact current generator 1, the other end of the adjustable inductor is connected with the input end of the electrical equipment 8, the damping of the whole electrical loop is changed by adjusting the size of the adjustable inductor 2, and the impact current generator 1 is triggered to generate impact current with a specific waveform and is applied to the electrical equipment 8; in this embodiment, the adjustable inductor 2 is of a coreless coil type, so that iron core saturation is avoided under a large current condition, and the size of the inductor is adjusted by adjusting the number of turns of a coil connected into a circuit.
The vibration sensor 3 may be fixed to the housing of the electrical apparatus 8 in various ways. The sensor can be installed through magnetic force of the magnetic base, can be fixedly installed through binding of a magic tape and glue, and can also be installed on the base through screws after the fixed base is installed on the surface of the electrical equipment; the vibration sensor 3 converts vibration signals collected from the electrical equipment 8 into voltage signals, in the embodiment, one vibration sensor 3 is fixed on each cross-shaped direction of the same section of the electrical equipment 8, four vibration sensors 3 are in a group, a group of sensors are fixed at intervals of 0.5m in the axial direction, the tail end of each vibration sensor 3 is connected with the data collection device 4 through a signal cable, in the embodiment, the vibration sensors 3 are miniature piezoelectric single-shaft acceleration sensors, the sensitivity of each vibration sensor 3 is 80-200 mV/g, the measurement range is 5-80g, and the central frequency range covers 0.1-30000 Hz.
The data acquisition device 4 is a data acquisition card, the data acquisition card is connected with the vibration test system 5 through an optical cable, the vibration test system 5 can perform frequency spectrum analysis on time domain signals obtained by vibration, and an entropy spectrum method and a cluster analysis method are adopted to perform characteristic analysis on frequency spectrums so as to identify the types of mechanical defects of the electrical equipment. In the present embodiment, the vibration testing system 5 is a PC upper computer. The data acquisition card can simultaneously acquire more than 4 groups of sensor data, transmits the acquired signals to a PC upper computer for spectrum analysis, and judges whether the mechanical structure of the electrical equipment has defects or not according to the spectrum analysis result.
During wiring, one end of the impact current generator 1 is connected with the ground, the output end of the impact current generator 1 is connected with one end of the adjustable inductor 2, and the output end of the impact current generator 1 is also connected with the oscilloscope 7 through the shunt 6; the other end of the adjustable inductor 2 is connected with the output end of the electrical equipment 8, and the output end of the electrical equipment 8 is connected with the ground; the vibration sensor 3 is arranged on the surface of the electrical equipment 8, and the tail end of the vibration sensor 3 is connected to the PC upper computer through the data acquisition device 4.
The invention discloses a method for detecting defects of electrical equipment by utilizing sweep frequency impulse current, which comprises the following steps of:
(a) the inductance of the adjustable inductor 2 is adjusted, so that the oscillation center frequency of the surge current waveform is changed to a proper value;
(b) charging the impulse current generator 1 to a preset voltage, triggering the impulse current generator 1, and applying the generated impulse current to the electrical equipment 8;
(c) the vibration sensor 3 collects vibration signals on the surface of the electrical equipment 8 and forms a frequency spectrogram after being converted by the vibration testing system 5;
(d) the vibration test system 5 analyzes the spectrogram and identifies whether the electrical equipment 8 has a mechanical structure defect.
In the step (d), the vibration testing system 5 performs characteristic analysis on the spectrogram by using an entropy spectrum method and a cluster analysis method, and identifies the type of the mechanical defect of the electrical equipment.
The invention can cause the vibration response of the electrical equipment by applying the impulse current excitation, detect the vibration response and realize the diagnosis and identification of the mechanical defects of the equipment by analyzing the vibration frequency spectrum.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (7)
1. A system for detecting defects of electrical equipment by utilizing sweep frequency impact current is characterized in that: the system comprises an impact current generator (1), an adjustable inductor (2), a vibration sensor (3), a data acquisition device (4) and a vibration test system (5); the impulse current generator (1) is connected with the adjustable inductor (2) in series and then is connected with one end of the electrical equipment (8); the vibration sensor (3) is arranged on the outer surface of the electrical equipment (8), and the vibration sensor (3) is connected to the vibration testing system (5) through the data acquisition device (4); the vibration testing system (5) performs frequency spectrum analysis on the vibration signals and identifies the type of mechanical defects of the electrical equipment (8); the adjustable inductor (2) is of a coreless coil type.
2. A system for detecting defects of electrical equipment using swept frequency impulse current as claimed in claim 1, wherein: the device is characterized by further comprising a current divider (6) and an oscilloscope (7), wherein the impact current generator (1) is connected with the oscilloscope (7) through the current divider (6) to detect the waveform of the impact current.
3. A system for detecting defects of electrical equipment using swept frequency impulse current as claimed in claim 1, wherein: the peak value of the output current of the impact current generator (1) is not lower than 80kA, and the energy is not lower than 15 kJ.
4. A system for detecting defects of electrical equipment using swept frequency impulse current as claimed in claim 1, wherein: the sensitivity of the vibration sensor (3) is 80-200 mV/g, the measurement range is 5-80g, and the central frequency range covers 0.1-30000 Hz.
5. A system for detecting defects of electrical equipment using swept frequency impulse current as claimed in claim 1, wherein: the data acquisition device (4) is a data acquisition card which simultaneously acquires more than 4 groups of sensor data.
6. A method for using the system for detecting defects of electrical equipment by using swept frequency impulse current as claimed in claim 1, comprising the steps of:
(a) the inductive reactance of the adjustable inductor (2) is adjusted, so that the oscillation center frequency of the impact current waveform is changed to a proper value;
(b) charging the impact current generator (1) to a preset voltage, triggering the impact current generator (1), and applying the generated impact current to the electrical equipment (8);
(c) the vibration sensor (3) collects vibration signals on the surface of the electrical equipment (8), and a frequency spectrogram is formed after the vibration signals are converted by the vibration testing system (5);
(d) the vibration test system (5) analyzes the spectrogram and identifies whether the electrical equipment (8) has mechanical structure defects.
7. The method of claim 6, wherein: in the step (d), the vibration testing system (5) performs characteristic analysis on the spectrogram by using an entropy spectrum method and a cluster analysis method, and identifies the category of the mechanical defect of the electrical equipment.
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| CN111426473B (en) * | 2020-05-19 | 2022-05-13 | 国网江苏省电力有限公司电力科学研究院 | GIS (gas insulated switchgear) equipment defect detection system and method by utilizing sweep frequency alternating current |
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| CN202384768U (en) * | 2011-12-14 | 2012-08-15 | 河南省电力勘测设计院 | Urban substation parallel capacitor device |
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| EP2991224A1 (en) * | 2014-08-29 | 2016-03-02 | Technische Universität Dortmund | High current pulse generator |
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| CN100373166C (en) * | 2005-11-30 | 2008-03-05 | 上海市电力公司 | Device for detecting transformer winding state utilizing sweep frequency power source exciting |
| CN101937047A (en) * | 2009-06-30 | 2011-01-05 | 上海市电力公司 | Method of utilizing vibration waveform for detecting state of transformer winding |
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| CN105137277B (en) * | 2015-09-11 | 2018-12-07 | 西安交通大学 | The diagnostic method of winding machine performance when a kind of transformer sudden short circuit |
| CN106569114A (en) * | 2016-10-19 | 2017-04-19 | 广东电网有限责任公司电力科学研究院 | Transformer intruding wave transient impact simulation test platform and method |
| CN109765455A (en) * | 2019-02-28 | 2019-05-17 | 国网陕西省电力公司电力科学研究院 | A kind of transformer winding detection platform and its operating method based on harmonic source |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202384768U (en) * | 2011-12-14 | 2012-08-15 | 河南省电力勘测设计院 | Urban substation parallel capacitor device |
| EP2991224A1 (en) * | 2014-08-29 | 2016-03-02 | Technische Universität Dortmund | High current pulse generator |
| CN204177919U (en) * | 2014-11-25 | 2015-02-25 | 广西电网有限责任公司电力科学研究院 | Based on the high direct voltage impact system of air reactor |
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