Power equipment partial discharge detection device

Abstract

The invention discloses a partial discharge detection device for power equipment. Comprising a built-in defect simulation electrode used for simulating various types of discharge defects and generating partial discharge, a power frequency AC voltage and test loop, a partial discharge pulse current detection system used for collecting high frequency pulse current signals, and a partial discharge ultrasonic signal detection system used for collecting ultrasonic signals. The partial discharge multispectral signal detection system is used for collecting multiple paths of optical pulse signals; the power frequency AC voltage and test loop is used for outputting power frequency AC voltage to the electrode so as to enable the electrode to generate partial discharge; and the multi-channel data acquisition card is used for accessing the acquired three signals to the computer for waveform display and signal processing. According to the invention, through the multichannel data acquisition card, acoustic, optical and electric signals obtained by synchronously detecting the partial discharge process are accessed to the computer for waveform display and signal processing, so that the characteristics and change rules of the partial discharge signals can be comprehensively known.

Description

Technical Field

[0001] The present invention relates to the field of power equipment detection, and in particular to a partial discharge detection device for power equipment. Background Art

[0002] With the development of sensing technology and signal processing analysis methods, the types of partial discharge detection methods have become more diversified. In response to various physical and chemical phenomena caused by partial discharge, mature partial discharge detection technologies for power equipment, such as pulse current method, ultrasonic method, ultra-high frequency method, optical measurement method and chemical detection method, have gradually been formed, and each has its own technical advantages.

[0003] However, the current partial discharge detection methods still have certain limitations. The reliability of data is difficult to guarantee when only a single detection method is used. In order to improve the detection efficiency and confidence of partial discharge of power equipment, it has become a trend to use multiple methods for joint detection. For complex application environments such as high gas pressure, high oil pressure and electromagnetic, the multi-method joint detection method will provide more abundant partial discharge information, but the current experimental platform still has shortcomings in terms of how to collect and process information with different characteristics and structures, improve the efficiency of partial discharge diagnosis, and give full play to the advantages of the joint detection method. Summary of the invention

[0004] The embodiment of the present invention provides a partial discharge detection device for power equipment, which studies the influence of different types of defects on partial discharge, ensures the comprehensiveness of partial discharge detection results, and connects the sound, light and electrical signals obtained by synchronously detecting the partial discharge process of discharge defects to a computer through a multi-channel data acquisition card for intuitive waveform display and signal processing.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a partial discharge detection device for power equipment, including: a test chamber, a built-in defect simulation electrode, a power frequency AC voltage and a test circuit, a partial discharge pulse current detection system, a partial discharge ultrasonic signal detection system, a partial discharge multi-spectral signal detection system, a multi-channel data acquisition card and a computer;

[0006] The built-in defect simulation electrode is used to accelerate the aging of the transformer oil in the test cavity to simulate various types of discharge defects and generate partial discharge;

[0007] The power frequency AC voltage and test circuit is connected to the first end of the built-in defect simulation electrode, and is used to output the power frequency AC voltage to the built-in defect simulation electrode, so that the built-in defect simulation electrode generates partial discharge;

[0008] The partial discharge pulse current detection system is used to collect high-frequency pulse current signals;

[0009] The partial discharge ultrasonic signal detection system is used to collect ultrasonic signals;

[0010] The partial discharge multi-spectrum signal detection system is used to collect multi-channel optical pulse signals;

[0011] The multi-channel data acquisition card is connected to the output ends of the partial discharge pulse current detection system, the partial discharge ultrasonic signal detection system and the partial discharge multi-spectrum signal detection system, and is used to connect the high-frequency pulse current signal, the ultrasonic signal and the multi-channel optical pulse signal to the computer for waveform display and signal processing.

[0012] The embodiment of the present invention is implemented, and the built-in defect simulation electrode is used to accelerate the aging of the transformer oil in the test chamber to simulate various types of discharge defects and generate partial discharge, so as to study the influence of different types of defects on partial discharge, ensure the comprehensiveness of the detection results, and accelerate the aging process of the transformer oil in the test chamber, which can shorten the overall detection cycle and improve the partial discharge detection efficiency. Then, the local discharge pulse current detection system is used to collect high-frequency pulse current signals, and the local discharge ultrasonic signal detection system is used to collect ultrasonic signals. At the same time, the local discharge multi-spectral signal detection system is used to collect multi-channel optical pulse signals, that is, the local discharge process of the discharge defect is synchronously detected by using the high-frequency pulse current method, the ultrasonic method and the optical measurement method. Then, through the multi-channel data acquisition card, the high-frequency pulse current signal, the ultrasonic signal and the multi-channel optical pulse signal obtained by the detection are connected to the computer for waveform display and signal processing. Through the intuitive display and comprehensive analysis of the multi-parameter signal, the characteristics and change laws of the local discharge signal can be more comprehensively understood, so that the physical and chemical phenomena such as the electric pulse, ultrasonic wave and optical radiation of the local discharge can be efficiently mastered, and corresponding measures can be taken based on the detection results to optimize the power equipment and improve the safety and reliability of the power equipment. In addition, the partial discharge pulse current detection system has high sensitivity and high-frequency response, and can capture the tiny current changes of partial discharge, while the partial discharge ultrasonic signal detection system has high resolution and wide bandwidth, and can capture the sound wave characteristics generated by partial discharge. As for the partial discharge multi-spectral signal detection system, it can simultaneously detect optical signals in multiple bands and provide rich spectral information.

[0013] As a preferred solution, the partial discharge multi-spectral signal detection system comprises: a filter set, a silicon photomultiplier tube array, a signal conditioning circuit and a battery power supply module;

[0014] The filter group is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain optical signals of multiple wavelength bands;

[0015] The silicon photomultiplier tube array is used to perform photoelectric conversion processing on the optical signals of the multiple wavelength bands output by the filter group, and obtain and output electrical signals corresponding to the optical signals of the multiple wavelength bands;

[0016] The signal conditioning circuit is used to amplify and condition the electrical signals corresponding to the optical signals of the multiple wavelength bands output by the silicon photomultiplier tube array to obtain multi-channel optical pulse signals;

[0017] The battery power supply module is used to provide electrical energy for the partial discharge multi-spectrum signal detection system.

[0018] The preferred solution of the embodiment of the present invention is to use a filter group to perform spectroscopic processing on the optical signal emitted by the discharge source, so that signals of different bands can be separated to obtain optical signals of multiple bands, thereby avoiding mutual interference between signals of different bands. Based on the optical signals of multiple bands, the spectral characteristics of the discharge source can be fully understood, and rich spectral information can be provided. In addition, the silicon photomultiplier tube array has high sensitivity and high resolution. The silicon photomultiplier tube array is used to perform photoelectric conversion processing on the optical signals of multiple bands output by the filter group, and the electrical signals corresponding to the optical signals of multiple bands are obtained and output, so that weak optical signals can be captured and ignored, so as to further improve the accuracy of partial discharge detection. Then, the signal conditioning circuit is used to amplify and condition the electrical signals corresponding to the optical signals of multiple bands output by the silicon photomultiplier tube array, so as to obtain multi-channel optical pulse signals, which can improve the signal-to-noise ratio of the signal, reduce interference, and ensure the accuracy of the partial discharge detection result.

[0019] As a preferred solution, the filter set includes: an ultraviolet filter, a visible light filter and an infrared filter;

[0020] Wherein, the ultraviolet filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the ultraviolet band;

[0021] The visible light filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the visible light band;

[0022] The infrared filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the infrared band.

[0023] The preferred solution of the embodiment of the present invention is to use ultraviolet filters, visible light filters and infrared filters respectively to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain signals in the ultraviolet band, the visible light band and the infrared band, so as to independently detect the signals of each band in the subsequent process and avoid mutual interference between signals of different bands. Among them, by detecting the ultraviolet band, the ultraviolet radiation generated by partial discharge can be captured, especially in phenomena such as bubbles and corona, which has an important indicative role. The visible light band is the most commonly used in optical detection. The analysis of the signal based on the visible light band can provide rich spectral information, which is convenient for detailed analysis of partial discharge. As for the signal of the infrared band, it is of great significance in the detection of thermal effect and long-wave radiation, and can provide information about the thermal effect and energy distribution of partial discharge.

[0024] As a preferred solution, the partial discharge ultrasonic signal detection system comprises: a piezoelectric transmitting sensor unit;

[0025] Wherein, the piezoelectric transmitting sensor unit is used to detect the ultrasonic vibration signal inside the test cavity and convert the ultrasonic vibration signal into an electrical signal; wherein, the ultrasonic vibration signal is generated when local discharge occurs in the built-in defect simulation electrode.

[0026] The preferred solution of the embodiment of the present invention is to use a piezoelectric transmitting sensor unit to detect the ultrasonic vibration signal inside the test cavity when the built-in defect simulation electrode generates partial discharge, so as to ensure timely detection of partial discharge phenomenon, and convert the ultrasonic vibration signal into an electrical signal to achieve non-contact detection of ultrasonic vibration, avoid affecting the equipment or materials inside the test cavity, and ensure the safety and reliability of the detection process. In addition, the characteristics of piezoelectric materials make the sensor highly sensitive, capable of capturing weak ultrasonic vibration signals and improving detection accuracy.

[0027] As a preferred solution, the partial discharge ultrasonic signal detection system further includes: a preamplifier;

[0028] Wherein, the preamplifier is used to amplify the electrical signal output by the piezoelectric transmitting sensor unit, and use the amplified electrical signal as the high-frequency pulse current signal.

[0029] The preferred scheme of implementing the embodiment of the present invention uses a preamplifier to amplify the electrical signal output by the piezoelectric transmitting sensor unit to obtain a high-frequency pulse current signal, which can significantly improve the signal strength, improve the signal-to-noise ratio, reduce the influence of environmental noise and other interference signals, and facilitate subsequent signal analysis and processing to further improve the accuracy of partial discharge detection.

[0030] As a preferred solution, the industrial frequency AC voltage and test circuit includes: a transformer, a voltage regulator, a protection resistor and a voltage divider;

[0031] Wherein, the first end of the transformer is connected to the first end of the protection resistor, the second end of the transformer is grounded, and the transformer is used to output an industrial frequency AC voltage;

[0032] The voltage regulator is used to adjust the output voltage of the transformer;

[0033] The second end of the protection resistor is connected to the first end of the voltage divider and the first end of the built-in defect simulation electrode respectively;

[0034] The second end of the voltage divider is grounded, and the voltage divider is used to measure the industrial frequency AC voltage output by the transformer.

[0035] In the preferred embodiment of the present invention, the transformer is used to output a stable industrial frequency AC voltage to ensure the voltage stability of the test loop, and the voltage regulator is used to adjust the output voltage of the transformer so that the current test loop meets different test requirements and is convenient for diversified detection. In addition, the first end of the protective resistor is connected to the first end of the transformer, and the second end of the protective resistor is respectively connected to the first end of the voltage divider and the first end of the built-in defect simulation electrode. The protective resistor can limit the current to prevent excessive voltage or current from damaging the test loop and the equipment.

[0036] As a preferred solution, the voltage divider comprises: a first voltage dividing resistor and a second voltage dividing resistor;

[0037] The first end of the first voltage-dividing resistor is respectively connected to the second end of the protection resistor and the first end of the built-in defect simulation electrode, and the second end of the first voltage-dividing resistor is connected to the multi-channel data acquisition card through a signal transmission line;

[0038] The first end of the second voltage-dividing resistor is connected to the second end of the first voltage-dividing resistor, and the second end of the second voltage-dividing resistor is grounded.

[0039] In a preferred embodiment of the present invention, the first voltage-dividing resistor and the second voltage-dividing resistor form a voltage divider, which can reduce the high voltage to a level suitable for measurement to flexibly adapt to different voltage requirements, and combined with a multi-channel data acquisition card connected to the second end of the first voltage-dividing resistor, it is possible to observe the current voltage level in real time to accurately adjust the voltage to meet the needs.

[0040] As a preferred solution, the built-in defect simulation electrode is: a tip discharge defect simulation electrode, a surface discharge defect simulation electrode or an air gap discharge defect simulation electrode;

[0041] Wherein, the ground electrode of the tip discharge defect simulation electrode is a circular plate electrode, and the high voltage electrode of the tip discharge defect simulation electrode is a needle electrode;

[0042] The ground electrode of the surface discharge defect simulation electrode is a circular plate electrode, and the high voltage electrode of the surface discharge defect simulation electrode is a cylindrical electrode;

[0043] The ground electrode of the air gap discharge defect simulation electrode is a circular plate electrode, the high voltage electrode of the air gap discharge defect simulation electrode is a cylindrical electrode, three layers of insulating cardboard are sandwiched between the ground electrode of the air gap discharge defect simulation electrode and the high voltage electrode of the air gap discharge defect simulation electrode, and a circular hole is provided in the center of the insulating cardboard in the middle position.

[0044] The preferred scheme of the embodiment of the present invention is implemented. Through the combination of needle electrode and circular plate electrode, the tip discharge phenomenon is effectively simulated, and the influence of tip defects on local discharge is studied. By using the combination of cylindrical electrode and circular plate electrode, the surface discharge process can be truly reproduced, and the discharge characteristics of surface defects can be analyzed. In addition, the specially designed insulating paperboard and circular holes can be used to accurately simulate the air gap discharge inside the oil-paper insulation, and the influence of air gap defects on the discharge behavior can be explored.

[0045] As a preferred solution, the partial discharge pulse current detection system comprises: a Rogowski coil and a grounding wire;

[0046] Wherein, the first end of the Rogowski coil is connected to the second end of the built-in defect simulation electrode, and the second end of the Rogowski coil is connected to the ground wire.

[0047] A preferred solution for implementing the embodiment of the present invention is that the Rogowski coil is a high-sensitivity and high-precision current detection device that can detect tiny pulse current signals. By connecting the first end of the Rogowski coil to the second end of the built-in defect simulation electrode, the weak current signal generated by local discharge can be captured.

[0048] As a preferred solution, the second end of the Rogowski coil is connected to the multi-channel data acquisition card via a signal transmission line.

[0049] In a preferred solution of implementing the embodiment of the present invention, the second end of the Rogowski coil is not only connected to the ground wire, but also connected to the multi-channel data acquisition card through a signal transmission line, and then the signal output by the second end of the Rogowski coil is connected to the computer for waveform display and signal processing. Based on the waveform display and signal processing results of the computer, it is determined whether the acquisition devices such as the multi-channel data acquisition card and the signal transmission line between the second end of the Rogowski coil and the multi-channel data acquisition card are working properly. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1: A schematic diagram of the structure of a partial discharge detection device for electric power equipment provided in Embodiment 1 of the present invention;

[0051] Figure 2 : Schematic diagram of the structures of three types of built-in defect simulation electrodes provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] Embodiment one:

[0054] Please refer to Figure 1 , is a partial discharge detection device for power equipment provided by an embodiment of the present invention, the device comprises the following structures: a test chamber 1, a built-in defect simulation electrode 2, an AC voltage and a test circuit 3, a partial discharge pulse current detection system 4, a partial discharge ultrasonic signal detection system 5, a partial discharge multi-spectral signal detection system 6, a multi-channel data acquisition card 7 and a computer 8; each structure is specifically as follows:

[0055] The built-in defect simulation electrode 2 is used to accelerate the aging of the transformer oil in the test chamber 1 to simulate various types of discharge defects and generate partial discharge.

[0056] In this embodiment, the main body material of the test chamber 1 is organic glass, and please refer to Figure 1 The test chamber 1 is also provided with components such as an oil valve 9, a pressure gauge 10 and a pressure release valve 11. In addition, a window is opened on the side of the test chamber 1, and optical glass and flanges are provided, which is conducive to installing a partial discharge multi-spectral signal detection system 6 to measure the optical signal.

[0057] As a preferred solution, the built-in defect simulation electrode 2 is: a tip discharge defect simulation electrode, a surface discharge defect simulation electrode or an air gap discharge defect simulation electrode; each electrode is specifically as follows:

[0058] The ground electrode of the tip discharge defect simulation electrode is a circular plate electrode, and the high voltage electrode of the tip discharge defect simulation electrode is a needle electrode.

[0059] As an example, see Figure 2(a), the ground electrode of the tip discharge defect simulation electrode is a circular plate electrode with a diameter of 75 mm and a thickness of 15 mm. The high-voltage electrode of the tip discharge defect simulation electrode is a needle electrode with a curvature radius of 50 μm. There is an oil-immersed cardboard with a thickness of 1 mm between the electrodes, and the needle electrode is 2 mm away from the cardboard.

[0060] The ground electrode of the surface discharge defect simulation electrode is a circular plate electrode, and the high voltage electrode of the surface discharge defect simulation electrode is a cylindrical electrode.

[0061] As an example, see Figure 2 (b), the ground electrode of the surface discharge defect simulation electrode is a circular plate electrode, the high voltage electrode of the surface discharge defect simulation electrode is a cylindrical electrode with a cross-sectional diameter of 25 mm, and the insulating paperboard is tightly pressed between the upper and lower electrodes.

[0062] The ground electrode of the air gap discharge defect simulation electrode is a circular plate electrode, the high voltage electrode of the air gap discharge defect simulation electrode is a cylindrical electrode, three layers of insulating cardboard are sandwiched between the ground electrode of the air gap discharge defect simulation electrode and the high voltage electrode of the air gap discharge defect simulation electrode, and a circular hole is provided in the center of the insulating cardboard in the middle position.

[0063] As an example, see Figure 2 (c), the ground electrode and high voltage electrode of the air gap discharge defect simulation electrode are consistent with the ground electrode and high voltage electrode of the surface discharge defect simulation electrode. Three layers of insulating cardboard are sandwiched between the ground electrode and the high voltage electrode of the air gap discharge defect simulation electrode. The middle layer of insulating cardboard has a circular hole with a diameter of 4 mm in the center, which is used to simulate the air gap inside the oil-paper insulation.

[0064] In this embodiment, please refer to Figure 1 The built-in defect simulation electrode 2 is arranged inside the test chamber 1. The electrodes of the three defect types, namely the tip discharge defect simulation electrode, the surface discharge defect simulation electrode and the air gap discharge defect simulation electrode, are all made of brass.

[0065] Please refer to Figure 1 The industrial frequency AC voltage and test circuit 3 are connected to the first end of the built-in defect simulation electrode 2, and are used to output the industrial frequency AC voltage to the built-in defect simulation electrode 2 so that the built-in defect simulation electrode 2 generates partial discharge.

[0066] In this embodiment, the power source in the power frequency AC voltage and test loop 3 is a transformer 12. Specifically, the transformer 12 is a non-corona power frequency test transformer with a rated voltage of 100 kV and a capacity of 20 kVA. In addition, a bushing 19 is installed on the upper cover of the test chamber 1 to fix the connection line between the power frequency AC voltage and test loop 3 and the built-in defect simulation electrode 2.

[0067] As a preferred option, please refer to Figure 1 The industrial frequency AC voltage and test circuit 3 includes the following components: a transformer 12, a voltage regulator 13, a protection resistor 14 and a voltage divider 15; the specific components are as follows:

[0068] The first end of the transformer 12 is connected to the first end of the protection resistor 14 , the second end of the transformer 12 is grounded, and the transformer 12 is used to output an industrial frequency AC voltage.

[0069] The voltage regulator 13 is used to adjust the output voltage of the transformer 12 .

[0070] The second end of the protection resistor 14 is connected to the first end of the voltage divider 15 and the first end of the built-in defect simulation electrode 2 respectively.

[0071] As an example, the protection resistor 14 uses a water resistor with a resistance of 200 MΩ.

[0072] A second end of the voltage divider 15 is grounded. The voltage divider 15 is used to measure the industrial frequency AC voltage output by the transformer 12 .

[0073] As an example, the voltage divider 15 is a resistor-capacitor voltage divider with a voltage division ratio of 2000:1, which is used to measure the high voltage signal.

[0074] As a preferred option, please refer to Figure 1 The voltage divider 15 includes the following components: a first voltage divider resistor and a second voltage divider resistor; the specific components are as follows:

[0075] The first end of the first voltage-dividing resistor is respectively connected to the second end of the protection resistor 14 and the first end of the built-in defect simulation electrode 2 , and the second end of the first voltage-dividing resistor is connected to the multi-channel data acquisition card 7 via a signal transmission line 18 .

[0076] The first end of the second voltage-dividing resistor is connected to the second end of the first voltage-dividing resistor, and the second end of the second voltage-dividing resistor is grounded.

[0077] The partial discharge pulse current detection system 4 is used to collect the high-frequency pulse current signal CH2.

[0078] As a preferred option, please refer to Figure 1 The partial discharge pulse current detection system 4 includes the following components: a Rogowski coil 16 and a grounding wire 17; the specific components are as follows:

[0079] The first end of the Rogowski coil 16 is connected to the second end of the built-in defect simulation electrode 2 , and the second end of the Rogowski coil 16 is connected to the ground wire 17 .

[0080] As a preferred solution, the second end of the Rogowski coil 16 is connected to the multi-channel data acquisition card 7 via a signal transmission line 18 .

[0081] The local discharge ultrasonic signal detection system 5 is used to collect the ultrasonic signal CH3.

[0082] As a preferred solution, the local discharge ultrasonic signal detection system 5 includes: a piezoelectric transmitting sensor unit; the unit is specifically as follows:

[0083] The piezoelectric transmitting sensor unit is used to detect the ultrasonic vibration signal inside the test cavity 1 and convert the ultrasonic vibration signal into an electrical signal; wherein the ultrasonic vibration signal is generated when the built-in defect simulation electrode 2 generates local discharge.

[0084] In this embodiment, a magnetic fixture is used to fix the piezoelectric emission sensor unit on the side of the test cavity 1, and an ultrasonic coupling agent is applied to the fixing position. Specifically, the resonant frequency of the piezoelectric acoustic emission sensor unit is 75kHz, and the detection bandwidth ranges from 15kHz to 150kHz. The piezoelectric emission sensor unit has the advantages of high reliability and strong anti-electromagnetic interference ability.

[0085] As a preferred solution, the local discharge ultrasonic signal detection system 5 further includes: a preamplifier; the device is specifically as follows:

[0086] The preamplifier is used to amplify the electrical signal output by the piezoelectric transmitting sensor unit, and use the amplified electrical signal as the high-frequency pulse current signal.

[0087] In this embodiment, the selected preamplifier can independently select the gain and filter range, and the amplifier gain and filter range are set to 40dB and 20-120kHz respectively.

[0088] The partial discharge multi-spectrum signal detection system 6 is used to collect multi-channel optical pulse signals.

[0089] In this embodiment, the partial discharge multi-spectrum signal detection system 6 collects three optical pulse signals CH4 to CH6.

[0090] As a preferred solution, the partial discharge multi-spectral signal detection system 6 includes the following structures: a filter set, a silicon photomultiplier (SiPM) array, a signal conditioning circuit and a battery power supply module; each structure is specifically as follows:

[0091] The filter group is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain optical signals of multiple bands.

[0092] As a preferred solution, the filter set includes the following structures: an ultraviolet filter, a visible light filter and an infrared filter; the specific structures of each are as follows:

[0093] The ultraviolet filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the ultraviolet band.

[0094] The visible light filter is used to perform spectroscopic processing on the light signal emitted by the discharge source to obtain a signal in the visible light band.

[0095] The infrared filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the infrared band.

[0096] It should be noted that the wavelength range corresponding to the ultraviolet band is 200nm~400nm, the wavelength range corresponding to the visible light band is 400nm~700nm, and the wavelength range corresponding to the infrared band is 700nm~900nm.

[0097] The silicon photomultiplier tube array is used to perform photoelectric conversion processing on the optical signals of the multiple wavebands output by the filter group, and obtain and output electrical signals corresponding to the optical signals of the multiple wavebands.

[0098] The signal conditioning circuit is used to amplify and condition the electrical signals corresponding to the optical signals of the multiple wavebands output by the silicon photomultiplier tube array to obtain multi-channel optical pulse signals.

[0099] In this embodiment, the signal conditioning circuit includes, in sequence but not limited to, an IU conversion module, a preamplifier and a demodulator.

[0100] The battery power supply module is used to provide power to the partial discharge multi-spectrum signal detection system 6 .

[0101] It should be noted that the partial discharge multi-spectrum signal detection system 6 has the advantages of small size, strong anti-interference ability and high detection efficiency, and can meet the needs of partial discharge optical signal detection.

[0102] The multi-channel data acquisition card 7 is connected to the output ends of the partial discharge pulse current detection system 4, the partial discharge ultrasonic signal detection system 5 and the partial discharge multi-spectrum signal detection system 6, and is used to connect the high-frequency pulse current signal, the ultrasonic signal and the multi-channel optical pulse signal to the computer 8 for waveform display and signal processing, so as to realize sound, light and electrical signal processing.

[0103] In this embodiment, the multi-channel data acquisition card 7 is synchronously connected to 6 signals, namely, voltage signal CH1, high-frequency pulse current signal CH2, ultrasonic signal CH3 and 3 optical pulse signals CH4-CH6. The partial discharge pulse current detection system 4 is connected to the multi-channel data acquisition card 7 through a signal transmission line 18, the partial discharge ultrasonic signal detection system 5 is connected to the multi-channel data acquisition card 7 through a signal transmission line 18, and the partial discharge multi-spectral signal detection system 6 is connected to the multi-channel data acquisition card 7 through a signal transmission line 18. Among them, the signal transmission line 18 adopts a 50Ω double-layer shielded single-core cable, and the connecting wires in the loop are all treated with anti-corona.

[0104] It should be noted that the multi-channel data acquisition card 7 and the computer 8 collect and process the partial discharge pulse phase distribution (phase resolved partial discharge, PRPD) spectrum of the high-frequency pulse current signal, the time domain waveform and spectrum of the ultrasonic signal, and the optical signal pulse PRPD spectrum.

[0105] As an example, the use steps of a partial discharge detection device for electric equipment provided in an embodiment of the present invention include steps S1 to S5, and each step is specifically as follows:

[0106] Step S1, open the oil valve 9, slowly inject the treated transformer oil into the test oil tank, install the designed tip discharge defect simulation electrode in the test cavity 1, install the local discharge pulse current detection system 4, the local discharge ultrasonic signal detection system 5, and the local discharge multi-spectral signal detection system 6 at the corresponding positions, and connect the signal transmission line 18 to the acquisition card, check the connection between the ground wire 17 and the signal transmission line 18, and check whether the acquisition device is working properly.

[0107] Step S2, before conducting the partial discharge acoustic, optical and electrical integrated detection experiment, record the background noise amplitude Unoise of each signal, then apply voltage and slowly increase the voltage by operating the non-halo power frequency test transformer 12, and observe the digital oscilloscope software on the computer 8, when the partial discharge pulse current detection system 4 begins to detect the partial discharge pulse, record the voltage at this time as the partial discharge initial voltage (PDIV).

[0108] Step S3, continue to increase the voltage and maintain a constant voltage between 1.1 and 1.5 times PDIV to ensure that an obvious discharge signal can be detected, and then keep the voltage unchanged until the end of the experiment.

[0109] Step S4, collect data regularly. Since data storage and processing require a certain amount of time, the data collection interval is set to 15 minutes. The waveform data of each signal is saved as a .csv file using the channel data acquisition card 7 software.

[0110] Step S5, the sample is broken down, and the experiment is finished. The output voltage of the test transformer 12 is reduced to zero, the power supply is cut off, the circuit is discharged using a conductive rod, the defect or voltage level is changed to carry out the next experiment, and the above steps are repeated during the experiment; and the sound, light and electrical signals are collected and processed by the computer 8 to realize automatic detection of partial discharge signals, and the amplitude and phase information of the corresponding pulses are recorded and saved as a .txt file, and the pulse phase distribution spectrum is analyzed to obtain the PRPD scatter diagram of the high-frequency pulse current signal of the tip discharge, the time domain waveform and spectrum diagram of the ultrasonic signal, and the PRPD scatter diagram of the optical signal pulse, and the sealing of the experimental platform and the electromagnetic compatibility of the sensing system are regularly checked.

[0111] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0112] The invention provides a partial discharge detection device for electric equipment. The device accelerates the aging of transformer oil in a test cavity by using a built-in defect simulation electrode, so as to simulate various types of discharge defects and generate partial discharge, so as to study the influence of different types of defects on partial discharge, ensure the comprehensiveness of the detection result, and accelerate the aging process of transformer oil in the test cavity, so as to shorten the overall detection period and improve the partial discharge detection efficiency. Then, a partial discharge pulse current detection system is used to collect high-frequency pulse current signals, and a partial discharge ultrasonic signal detection system is used to collect ultrasonic signals. Meanwhile, a partial discharge multi-spectrum signal detection system is used to collect multi-channel optical pulse signals, that is, a high-frequency pulse current method, an ultrasonic method and an optical measurement method are used to synchronously detect the partial discharge process of the discharge defect. Then, through a multi-channel data acquisition card, the high-frequency pulse current signals, ultrasonic signals and multi-channel optical pulse signals obtained by the detection are connected to a computer for waveform display and signal processing. Through the intuitive display and comprehensive analysis of multi-parameter signals, the characteristics and change laws of the partial discharge signals can be more comprehensively understood, so that the physical and chemical phenomena such as electric pulses, ultrasonic waves and optical radiation of the partial discharge can be efficiently mastered, and corresponding measures can be taken based on the detection results to optimize the electric equipment and improve the safety and reliability of the electric equipment. In addition, the partial discharge pulse current detection system has high sensitivity and high-frequency response, and can capture the tiny current changes of partial discharge, while the partial discharge ultrasonic signal detection system has high resolution and wide bandwidth, and can capture the sound wave characteristics generated by partial discharge. As for the partial discharge multi-spectral signal detection system, it can simultaneously detect optical signals in multiple bands and provide rich spectral information.

[0113] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A partial discharge detection device for electric power equipment, characterized in that: include: Test chamber, built-in defect simulation electrode, power frequency AC voltage and test circuit, partial discharge pulse current detection system, partial discharge ultrasonic signal detection system, partial discharge multi-spectral signal detection system, multi-channel data acquisition card and computer; The built-in defect simulation electrode is used to accelerate the aging of the transformer oil in the test cavity to simulate various types of discharge defects and generate partial discharge; The power frequency AC voltage and test circuit is connected to the first end of the built-in defect simulation electrode, and is used to output the power frequency AC voltage to the built-in defect simulation electrode, so that the built-in defect simulation electrode generates partial discharge; The partial discharge pulse current detection system is used to collect high-frequency pulse current signals; The partial discharge ultrasonic signal detection system is used to collect ultrasonic signals; The partial discharge multi-spectrum signal detection system is used to collect multi-channel optical pulse signals; The multi-channel data acquisition card is connected to the output ends of the partial discharge pulse current detection system, the partial discharge ultrasonic signal detection system and the partial discharge multi-spectrum signal detection system, and is used to connect the high-frequency pulse current signal, the ultrasonic signal and the multi-channel optical pulse signal to the computer for waveform display and signal processing.

2. A partial discharge detection device for electric power equipment as claimed in claim 1, characterized in that: The partial discharge multi-spectral signal detection system comprises: a filter set, a silicon photomultiplier tube array, a signal conditioning circuit and a battery power supply module; The filter group is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain optical signals of multiple wavelength bands; The silicon photomultiplier tube array is used to perform photoelectric conversion processing on the optical signals of the multiple wavelength bands output by the filter group, and obtain and output electrical signals corresponding to the optical signals of the multiple wavelength bands; The signal conditioning circuit is used to amplify and condition the electrical signals corresponding to the optical signals of the multiple wavelength bands output by the silicon photomultiplier tube array to obtain multi-channel optical pulse signals; The battery power supply module is used to provide electrical energy for the partial discharge multi-spectrum signal detection system.

3. A partial discharge detection device for electric power equipment as claimed in claim 2, characterized in that: The filter set includes: an ultraviolet filter, a visible light filter and an infrared filter; Wherein, the ultraviolet filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the ultraviolet band; The visible light filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the visible light band; The infrared filter is used to perform spectroscopic processing on the optical signal emitted by the discharge source to obtain a signal in the infrared band.

4. A partial discharge detection device for electric power equipment as claimed in claim 1, characterized in that: The partial discharge ultrasonic signal detection system comprises: a piezoelectric transmitting sensor unit; Wherein, the piezoelectric transmitting sensor unit is used to detect the ultrasonic vibration signal inside the test cavity and convert the ultrasonic vibration signal into an electrical signal; wherein, the ultrasonic vibration signal is generated when local discharge occurs in the built-in defect simulation electrode.

5. A partial discharge detection device for electric power equipment as claimed in claim 4, characterized in that: The partial discharge ultrasonic signal detection system further includes: a preamplifier; Wherein, the preamplifier is used to amplify the electrical signal output by the piezoelectric transmitting sensor unit, and use the amplified electrical signal as the high-frequency pulse current signal.

6. A partial discharge detection device for electric power equipment as claimed in claim 1, characterized in that: The industrial frequency AC voltage and test circuit includes: a transformer, a voltage regulator, a protective resistor and a voltage divider; Wherein, the first end of the transformer is connected to the first end of the protection resistor, the second end of the transformer is grounded, and the transformer is used to output an industrial frequency AC voltage; The voltage regulator is used to adjust the output voltage of the transformer; The second end of the protection resistor is connected to the first end of the voltage divider and the first end of the built-in defect simulation electrode respectively; The second end of the voltage divider is grounded, and the voltage divider is used to measure the industrial frequency AC voltage output by the transformer.

7. A partial discharge detection device for electric power equipment as claimed in claim 6, characterized in that: The voltage divider comprises: a first voltage dividing resistor and a second voltage dividing resistor; The first end of the first voltage-dividing resistor is respectively connected to the second end of the protection resistor and the first end of the built-in defect simulation electrode, and the second end of the first voltage-dividing resistor is connected to the multi-channel data acquisition card through a signal transmission line; The first end of the second voltage-dividing resistor is connected to the second end of the first voltage-dividing resistor, and the second end of the second voltage-dividing resistor is grounded.

8. A partial discharge detection device for electric power equipment as claimed in claim 1, characterized in that: The built-in defect simulation electrode is: a tip discharge defect simulation electrode, a surface discharge defect simulation electrode or an air gap discharge defect simulation electrode; Wherein, the ground electrode of the tip discharge defect simulation electrode is a circular plate electrode, and the high voltage electrode of the tip discharge defect simulation electrode is a needle electrode; The ground electrode of the surface discharge defect simulation electrode is a circular plate electrode, and the high voltage electrode of the surface discharge defect simulation electrode is a cylindrical electrode; The ground electrode of the air gap discharge defect simulation electrode is a circular plate electrode, the high voltage electrode of the air gap discharge defect simulation electrode is a cylindrical electrode, three layers of insulating cardboard are sandwiched between the ground electrode of the air gap discharge defect simulation electrode and the high voltage electrode of the air gap discharge defect simulation electrode, and a circular hole is provided in the center of the insulating cardboard in the middle position.

9. A partial discharge detection device for electric power equipment as claimed in claim 1, characterized in that: The partial discharge pulse current detection system comprises: a Rogowski coil and a grounding wire; Wherein, the first end of the Rogowski coil is connected to the second end of the built-in defect simulation electrode, and the second end of the Rogowski coil is connected to the ground wire.

10. A partial discharge detection device for electric power equipment as claimed in claim 9, characterized in that: The second end of the Rogowski coil is connected to the multi-channel data acquisition card via a signal transmission line.

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