CN105388406A - Gas insulated electric equipment partial discharge multi-source joint detection method - Google Patents

Abstract

The invention belongs to the technical field of on-line monitoring of the insulation state of sulfur hexafluoride (SF ₆ ) gas-insulated electrical equipment, and specifically relates to a multi-source combined detection method for partial discharge of gas-insulated electrical equipment. The present invention mainly includes experiment preparation, cleaning stainless steel cylinder body, charging _SF6 gas, power frequency AC SF6 gas PD test, pulse current method detection, ultra-high frequency sensor detection, fluorescent optical fiber sensor detection, discharge gas collection and component detection, etc. step. The method of the invention is simple to operate and easy to popularize, and provides reference for a joint detection method of multi-dimensional information. The invention is widely used in multi-sensor combined detection of partial discharge of SF ₆ gas-insulated electrical equipment under power frequency conditions, and provides a simple test scheme for multi-dimensional information extraction of PD decomposition characteristics and decomposition theory.

Description

A multi-source combined detection method for partial discharge of gas-insulated electrical equipment

technical field

The invention belongs to the technical field of on-line monitoring of the insulation state of sulfur hexafluoride (SF ₆ ) gas-insulated electrical equipment, and in particular relates to a multi-sensor joint detection test method for partial discharge of gas-insulated electrical equipment.

Background technique

SF6 gas insulated switchgear (GIS for short) using sulfur hexafluoride gas (SF ₆ ) as the insulation and arc extinguishing medium has developed rapidly due to its advantages of high reliability, small maintenance, small footprint, and flexible configuration. And it is widely used in the high voltage and extra/ultra high voltage fields of the power system, and has gradually become one of the first choice equipment and important symbols of modern substations. GIS has always been generally considered as low-maintenance or even maintenance-free high-voltage electrical equipment, but according to the statistics of the International Power Grid Commission (CIGRE), its failure rate is much higher than the failure level recommended by IEC standards. Some types of insulation faults that are more harmful to equipment, such as faults caused by particles or foreign objects left on the GIS shell or insulator, faults caused by loose shielding or poor electrical contact, etc., after installation, field tests or insulation diagnosis It is difficult to be found, and it gradually develops into a fault as the running time goes by. And once a fault occurs, due to the fully sealed structure of GIS, it is very difficult to perform fault location and maintenance work; compared with other conventional equipment, the average power outage maintenance time after the accident is longer, and the power outage range is larger, often involving non-faulty components . As a hub for transmission and distribution of electric energy in the power grid, it is self-evident that the safe and reliable operation of GIS plays a role in the stable operation of the UHV power system. Therefore, it is very necessary to effectively monitor the early insulation status of SF ₆ gas-insulated electrical equipment. assessment and early warning.

From the consensus formed by the current research and the experience of GIS operation and maintenance, the main cause of GIS insulation failure is that there are various defects inside GIS. PD), under the continuous action of electric field and thermal field, PD continues to intensify, which eventually leads to breakdown failure of UHV GIS equipment. From the perspective of the types of defects, there are mainly serious assembly errors, free conductive particles, metal protrusions, insulator surface and internal defects, poor electrical or mechanical contact between conductors, etc. The most common electrical fault characteristic of GIS is the generation of PD before complete insulation breakdown or flashover. Since GIS accidents are mainly caused by insulation faults, and the main manifestation of insulation faults in the early stage is PD, PD is not only the main cause of insulation degradation, but also a characteristic quantity that characterizes insulation conditions. Therefore, the multi-sensor combined detection experimental method for partial discharge of gas-insulated electrical equipment of the present invention can find many internal defects to a certain extent, which has important practical significance for ensuring the safe and reliable operation of GIS.

At present, domestic and foreign research on PD online monitoring methods for SF ₆ gas-insulated electrical equipment mainly focuses on the experimental method of a single monitoring method, such as the "Sulfur Hexafluoride Discharge Decomposition Component Analysis System and Its Application Method" with the patent number ZL2007100784930, the patent Patent No. ZL201010157377.X "Ultra-high frequency partial discharge discharge monitoring and acquisition method, device and system", and patent No. ZL200910104566.8 "Infrared detection device and method for trace components of sulfur hexafluoride gas discharge" and other patents , are all GIS online monitoring methods based on a single partial discharge signal, which cannot make full use of the light, electricity, sound, chemical and other information generated by partial discharge to conduct a comprehensive diagnosis of equipment failures.

The insulation performance of GIS equipment is a direct factor that determines its effective life cycle. Accurately evaluating and mastering the real insulation status of GIS equipment is a prerequisite for power companies to protect equipment assets. At the same time, adopting effective fault diagnosis technology for serious insulation defects that already exist and may lead to insulation degradation and failure is a powerful guarantee for maintenance personnel to further choose the right time to carry out targeted maintenance strategies. The fault diagnosis scheme based on the multi-sensor joint detection experimental method of gas-insulated electrical equipment partial discharge of the present invention is not only the basis for realizing the life-span management of GIS equipment, but also plays a vital role in improving the safety and economy of the entire power grid effect.

Contents of the invention

The purpose of this invention is to provide a kind of SF ₆ gas-insulated electrical equipment partial discharge multi-sensor joint detection experimental method for the single partial discharge signal detection method of existing SF ₆ gas-insulated electrical equipment, simulate SF ₆ gas-insulated electrical equipment in the laboratory Partial discharge under various typical defect models in electrical equipment, so as to obtain characteristic information such as sound, light, and composition of partial discharge, and provide experiments for fault diagnosis and insulation state evaluation of SF ₆ gas-insulated electrical equipment based on multi-source partial discharge information Base.

Technical scheme of the present invention is:

A multi-sensor joint detection experimental method for partial discharge of gas-insulated electrical equipment, characterized in that it specifically includes:

Experimental preparation steps: first place the artificial insulation defect model and dedust the device, then check the air tightness of the test device, then use gas to clean the stainless steel cavity, and finally inflate with SF ₆ gas;

The steps of the joint detection simulation experiment of SF ₆ gas PD signal under the condition of power frequency AC, specifically include:

Detection experiment 1, inherent defect test: To carry out the SF ₆ gas PD test, the inherent PD characteristics of the entire test device must be tested. Under the same test conditions, when the model without artificial defects is simulated, the test device does not have partial discharge. The threshold value of the test voltage; complete step (1) without artificially simulating defects, and after checking the connection safety of the test circuit, turn on the power supply and adjust the power frequency voltage loaded on the device without artificial defect models through the voltage regulating table. As the external processing frequency voltage is gradually increased, observe the signal on the digital storage oscilloscope connected to the detection device. Once a small discharge pulse signal is found, record and define the external voltage applied to the device at this moment as the intrinsic starting point of the device. Initial PD voltage U _g ; after completing the determination of the initial PD voltage value, reduce the applied voltage to 0 and cut off the connection between the input terminal of the voltage regulation console and the 220V/50Hz mains, and use the grounding rod to test all the voltages in the entire test device. The high-voltage end of the equipment is grounded and discharged; then the vacuum pump ball valve is turned on, the external vacuum pump is turned on to vacuumize the discharge chamber, and when the vacuum pressure gauge shows that it is below 0.01MPa, the vacuum pump ball valve and the vacuum pump are sequentially closed;

Detection experiment 2, power frequency AC SF ₆ gas PD test: first open the quartz glass observation window on the side of the gas discharge chamber, manually connect the prepared defect simulation model to it through the thread structure of the grounding conductive rod, and through the bottom of the grounding conductive rod The adjusting device adjusts the distance between the two electrodes of the defect so that the electrodes are closely connected with the two ends of the defect; then install the quartz glass through the connecting flange, seal it with an "O"-shaped rubber pad and press it with 12 screws with a diameter of 15mm Fix; then use SF ₆ to carry out gas cleaning on the stainless steel cavity, after completing this step, continue to pour 0.04MPa SF ₆ gas into the stainless steel cavity, turn on the power and adjust the device loaded on the artificial defect model through the pressure regulating table Observe the signal on the digital storage oscilloscope connected to the detection device. Once a tiny discharge pulse signal is found, record and define the external applied voltage on the device at this moment as the initial PD voltage U _st of the device. Taking U _st as the benchmark, set eight power frequency applied voltages of 1.1U _st , 1.2U _st , 1.3U _st , 1.4U _st , 1.5U _st , 1.6U _st , 1.7U- _st , and 1.8U _st to carry out the test. The test voltage applied to the defect model should not exceed the inherent initial PD voltage U _g of the device; continue to adjust the power frequency externally applied voltage to 1.2U _st , and conduct continuous 96h testing of artificial insulation defects at a voltage of 1.2U- _st For PD test, the test data is collected every 12 hours; after 96 hours of continuous PD test, eight sampling data of an artificial insulation defect at the test voltage can be obtained; the external voltage is reduced to 0 and the input of the voltage regulation console is cut off Connect the terminal to the 220V/50Hz mains, use a grounding rod to ground and discharge the high-voltage terminals of all equipment in the entire test device; then turn on the vacuum ball valve, turn on the external vacuum pump to vacuumize the discharge chamber, and observe the vacuum pressure When the table shows that it is below 0.01MPa, close the vacuum pump ball valve and the vacuum pump in order and disconnect them;

Then use SF ₆ to carry out gas cleaning to the stainless steel cavity, after completing this step, continue to pour 0.04MPa of SF ₆ gas into the stainless steel cavity, and adjust the applied voltage of power frequency to 1.3 U _st through the voltage regulating table. Perform continuous 96h PD test on artificial insulation defects at a voltage of 1.3U _st , and collect test data every 12 hours; after 96 hours of continuous PD test, you can get eight sampling data of an artificial insulation defect under this test voltage ;Reduce the applied voltage to 0 and cut off the connection between the input terminal of the voltage regulating console and the 220V/50Hz mains, use the grounding rod to discharge the high-voltage end of all equipment in the entire test device to the ground; then turn on the vacuum ball valve and open the external The vacuum pump vacuumizes the discharge chamber, and when the vacuum pressure gauge shows that it is below 0.01MPa, close the vacuum pump ball valve and the vacuum pump in sequence and disconnect them;

Repeat the test steps of air washing and pressurization in this way to complete eight power frequency external applied voltages of 1.1U _st , 1.2U _st , 1.3U _st , 1.4U _st , 1.5U _st , 1.6U _st , 1.7U _st , and 1.8U _st Based on the experimental data, the researchers extracted and characterized the PD intensity according to the data information obtained from the content of various SF ₆ decomposition gases and gas production rates, ultra-high frequency signals, and optical signals of fluorescent optical fibers under eight test voltages. To study the mechanism of PD decomposition of SF ₆ gas;

Detection experiment 3, pulse current detection: use the parallel method in the IEC60270 method to measure the PD pulse voltage signal, connect a partial discharge calibrator in parallel with the artificial insulation defect in the gas discharge chamber, and pass the partial discharge calibrator in the insulation defect The two poles generate a pulse signal with known discharge capacity, and the pulse voltage peak value U at both ends of the detection resistor can be measured by the connected digital storage oscilloscope, and the pulse voltage amplitude U is linearly related to the apparent discharge capacity Q, so Calculate the apparent discharge capacity Q according to the peak value U of the pulse voltage measured by the pulse current method;

Detection experiment 4, ultra-high frequency sensor detection: before using the voltage regulator to pressurize, the ultra-high frequency sensor is fixed and placed externally at the position facing the insulation defect, and the background noise is recorded on the digital storage oscilloscope through the ultra-high frequency sensor to understand the experimental environment Noise level, and then during the 96h continuous PD test process, the digital storage oscilloscope is connected to the UHF signal every 11~12h to collect the PD signal of the power frequency cycle, and the sampling frequency of the oscilloscope is set to 50MS/s. The resolution is 2ms/div, the number of sampling points is 1M, that is, the time length of 20ms. According to experience, when the partial discharge signal on the digital oscilloscope is judged to be stable, the researchers start to collect the discharge waveform data of 2500 power frequency cycles under each test voltage , and at the same time access the phase information of the power frequency reference voltage in the oscilloscope through the cable drawn from the capacitive voltage divider;

Detection experiment five, fluorescent fiber sensor detection: During the 96h continuous PD test, connect the digital storage oscilloscope to the fluorescent fiber for collection every 11 to 12h, set the sampling frequency of the oscilloscope to 50MS/s, and the time resolution to 2ms/s div, the number of sampling points is 1M, that is, the time length of 20ms, start to collect 2500 power frequency cycle discharge waveform data under each test voltage, and at the same time connect the cable drawn from the capacitor voltage divider to the oscilloscope to obtain the power frequency reference voltage phase information;

Detection experiment 6, collection and detection of discharge gas: During the 96h continuous PD test, after 12h of discharge, reduce the applied voltage to 0 and cut off the connection between the input terminal of the voltage regulating console and the 220V/50Hz mains, use the grounding The stick discharges the high-voltage end of all equipment in the entire test device to the ground; then connect the sampling bag to the sampling port and turn on the sampling ball valve to collect the discharge gas once, and close the sampling ball valve after completion; then adjust the voltage to the next test voltage Continue to carry out the PD test, and then carry out another discharge gas collection after 12 hours and so on.

In the above-mentioned experimental method for multi-sensor joint detection of partial discharge of gas-insulated electrical equipment, in the sixth detection experiment, Shimadzu GC/MS-QP2010Ultra is used to qualitatively and quantitatively measure the discharge gas collected each time. Analysis; the gas components are separated by a special capillary column with a film thickness of 8um, an inner diameter of 0.32mm, and a length of 60m, and are detected by an MSD detector; this method uses 99.999% high-purity He as the carrier gas, and the working conditions are: The temperature of the column oven is raised at a constant temperature of 35°C for 7.5 minutes, at a rate of 70°C/min to 105°C for 10 minutes, at a rate of 100°C/min to 250°C for 3.5 minutes, and the temperature of the injection port is 220°C. Pressure flow control mode, the pressure is 55kPa, the total flow is 16.3mL/min, the column flow is 1.21mL/min, the linear velocity is 28cm/sec, the purge flow is 3mL/min, the split ratio is 10, and the ion source temperature is 200 ℃, the interface temperature of the chromatographic mass spectrometer is 220 ℃, the solvent delay time is 0min, the micro-scanning width is 0u, and the detector voltage is 0kV; the ionization method is electric bombardment ionization; the acquisition method is SIM quantitative analysis; the scanning interval time is 0.3s; this method can realize Effective separation and detection of the concentration of various gases such as CF ₄ , CO ₂ , SO ₂ F ₂ , SOF ₂ , H ₂ S, SO ₂ , CS ₂ , the decomposition components of SF ₆ under PD;

The gas sample obtained by sampling is carried by the high-pressure carrier gas (helium used in this paper) that has been decompressed and purified and flows into the chromatographic column to achieve effective separation of different components. Obtain the electrical signal of the content of the reaction component; the function of the detector is to convert the proportion of the gas component content into an electrical signal output, and the test report output and displayed by the data processing workstation is called a chromatogram; obviously, the peak area of the chromatogram The size is the size of the detector output electrical signal, which is proportional to the component content; at the same time, through the chromatographic system under the same conditions, the retention time of the same substance with different concentrations in the detector remains unchanged, so it can be detected in advance. For the retention time of the standard gas, use the following formula to quantitatively calibrate the measured product:

$\frac{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}$

Among them, c _s and ci represent the concentrations of the measured _i -th gas component and its standard gas, respectively, A _s and A _i are the chromatographic peak areas, and K _i is the absolute correction factor.

In the above-mentioned experimental method for partial discharge multi-sensor joint detection of gas-insulated electrical equipment, the specific operation of placing the artificial insulation defect model and device dust removal treatment is as follows: first, accurately connect each device according to the schematic diagram of the test circuit, and perform all the tests in turn. The test equipment is grounded to ensure the electrical safety of the test; the spherical top cover of the stainless steel columnar cavity of the gas discharge chamber in the test device is uncovered, and the inner wall of the stainless steel cavity and the artificial defect model are cleaned and wiped with ethanol liquid to remove For impurities and dust on the device, the two ends of the artificial defect are screwed together with the high and low pressure guide rods respectively, and then the spherical top cover is sealed to ensure that the impurities and dust will not interfere with the entire test.

In the above-mentioned multi-sensor joint detection experimental method for partial discharge of gas-insulated electrical equipment, the specific operation of checking the airtightness of the test device is: first, turn on the vacuum pump connected to the test device, and pump it through the gas charging port of the stainless steel cavity. Air, observe the vacuum gauge, when the pointer on the vacuum pressure gauge points to 0-0.01MPa, close the vacuum ball valve and vacuum pump on the device, mark the pointer gauge with a marker pen, and observe the mark on the vacuum pressure gauge after standing still for about 24 hours Whether there is a change, if the above-mentioned vacuum pressure indication remains at 0-0.015MPa and there is almost no change in the mark, it is confirmed that the airtightness of the device is good under vacuum; open the valve of the purchased SF ₆ gas cylinder and the gas discharge chamber. Enter the balloon valve, manually adjust the gas valve to inject SF ₆ gas into the stainless steel cavity at a constant speed, observe the air pressure pointer on the vacuum voltmeter to 0.4-0.5MPa, mark the meter with a marker pen, and close the above-mentioned SF ₆ gas cylinders in turn Check the valve and inlet ball valve after standing for 24 hours. When the pointer is still at 0.4-0.5MPa and the mark is almost unchanged, it shows that the gas discharge chamber is well sealed under air pressure, and finally ensures the safety of the gas test. sex.

In the above-mentioned experimental method for partial discharge multi-sensor joint detection of gas-insulated electrical equipment, the specific operation of using gas to clean the stainless steel cavity is as follows: first, connect a vacuum pump externally, and vacuumize the above-mentioned stainless steel cavity through the opened vacuum pump ball valve. When the vacuum indicated on the vacuum pressure gauge is 0-0.01MPa, close the above-mentioned vacuum pump ball valve and vacuum pump in turn; then connect the SF ₆ gas cylinder externally, and inject SF ₆ into the above-mentioned stainless steel cavity through the gas cylinder gas valve and the sampling ball valve. Gas, raise the air pressure value in the stainless steel chamber to the range of 0.3-0.4MPa, clean the stainless steel chamber, and let it stand for 4-6 hours to decompose the SF ₆ gas attached to the stainless steel chamber in the previous test The gas and moisture are fully vaporized and released; then repeat the above-mentioned process of vacuuming and injecting SF ₆ gas, so as to ensure that the impurity gas and inherent moisture content in the stainless steel cavity are reduced to a level that will not affect the test results.

In the above-mentioned experimental method for partial discharge multi-sensor joint detection of gas-insulated electrical equipment, the specific operation of using SF ₆ gas inflation is as follows: first, connect the SF ₆ gas cylinder externally, and use the valve of the gas cylinder and the inlet ball valve to control the gas pressure of the gas cylinder. Inject SF ₆ gas into the stainless steel cavity, and when the pointer of the gas pressure gauge is stable at 0.4MPa, then close the valve of the SF ₆ gas cylinder and the inlet ball valve in sequence; let it stand for 4 to 6 hours to make the SF ₆ evenly disperse in the gas discharge indoor.

The present invention has following advantages: 1. the present invention provides to SF ₆ gas-insulated electrical equipment partial discharge multi-sensor joint detection test method, has remedied the incompleteness that the single detection method of existing SF 6 gas-insulated electrical equipment obtains PD information, for The state assessment of SF ₆ gas-insulated electrical equipment and the development and research of fault diagnosis technology provide experimental basis; 2. The detachable insulation defect model framework in the device of the present invention includes the common defects of SF ₆ gas-insulated electrical equipment, and provides a The developmental insulation defect carrying platform can also be tested for other defects, which is very forward-looking. 3. The gas component detection system in the device of the present invention uses a gas chromatography-mass spectrometer, which can detect various decomposition gases of SF ₆ gases such as SO ₂ F ₂ , SOF ₂ , CO ₂ , CF ₄ , H ₂ S, SO ₂ , etc. Product content, high detection sensitivity, less sample consumption, good selectivity, and detection accuracy can reach ppmv level; 4. The ultra-high frequency sensor adopted in the present invention is a self-made antenna, which has high sensitivity and good selectivity and precision; 5. the joint detection method that the present invention adopts is by same digital storage oscilloscope and collects the partial discharge characteristic information under the same SF gas PD decomposition simultaneously, and test data has very high scientificity; _6. the inventive method is simple to operate, It is easy to popularize and provides a reference for multi-dimensional information joint detection methods. The invention is widely used in multi-sensor combined detection of partial discharge of SF ₆ gas-insulated electrical equipment under power frequency conditions, and provides a simple test scheme for multi-dimensional information extraction of PD decomposition characteristics and decomposition theory.

Description of drawings

Fig. 1 is the schematic block diagram of the test circuit of the device of the present invention;

Fig. 2 is the structural representation of the gas discharge chamber of device of the present invention;

Fig. 3 is the top view of Fig. 2;

Fig. 4a is the schematic diagram of the structure of the artificial insulation defect device utilized in the present invention (conductive rod protrusion defect)

Fig. 4b is a schematic diagram of the structure of the artificial insulation defect device used in the present invention (defect of metal attachment on the surface of the insulator).

Fig. 4c is a schematic diagram of the structure of the artificial insulation defect device used in the present invention (insulator hole/crack defect).

Fig. 4d is a schematic diagram of the structure of the artificial insulation defect device utilized in the present invention (free metal particle defect).

Fig. 5 is a functional block diagram of the pulse current method calibration circuit adopted in the method of the present invention.

Fig. 6 is the calibration curve of embodiment 1 pulse current method.

Fig. 7 is the total ion chromatogram (totalionchromatogram, TIC) of the mixed sample gas detected by the method in Example 1.

Fig. 8 is a standard gas configuration table used for quantitative calibration of the gas chromatography-mass spectrometer in Example 1.

FIG. 9 is a calibration curve of CF ₄ obtained by quantitatively calibrating the gas chromatography-mass spectrometer in Example 1 using the standard gases configured in Table 1.

FIG. 10 is a calibration curve of CO ₂ obtained by quantitatively calibrating the gas chromatography-mass spectrometer using the standard gases configured in Table 1 in Example 1.

FIG. 11 is a calibration curve of SO ₂ F ₂ obtained by quantitatively calibrating the gas chromatography-mass spectrometer using the standard gases configured in Table 1 in Example 1.

FIG. 12 is a calibration curve of SOF ₂ obtained by quantitatively calibrating the gas chromatography-mass spectrometer using the standard gases configured in Table 1 in Example 1.

FIG. 13 is a calibration curve of H ₂ S obtained by quantitatively calibrating the gas chromatography-mass spectrometer using the standard gases configured in Table 1 in Example 1. FIG.

Fig. ₁₄ is the calibration curve of SO2 obtained by quantitatively calibrating the gas chromatography-mass spectrometer using the standard gases configured in Table 1 in Example 1.

Fig. 15 is the calibration curve of CS ₂ obtained by quantitatively calibrating the gas chromatography-mass spectrometer using the standard gases configured in Table 1 in Example 1.

detailed description

The present invention will be further described below in combination with specific embodiments.

In the figure: 1. Power supply voltage regulating console, 2. No partial discharge power frequency test transformer, 3. No partial discharge protection resistor, 4. Power frequency capacitor voltage divider, 5. Coupling capacitor, 6. Detection impedance, 7. Gas discharge chamber, 8. Artificial insulation defect model, 9. Fluorescent optical fiber sensor, 10. Optical fiber coupler, 11. Ordinary optical fiber, 12. Gas chromatography mass spectrometer, 13. Optical fiber adapter, 14. Photomultiplier tube, 15. UHF microstrip antenna, 16. digital storage oscilloscope, 17. high-voltage guide rod, 18. high-voltage bushing, 19 ellipsoidal top cover, 20. screw, 21. flange, 22. stainless steel columnar cavity, 23. vacuum Pressure gauge, 24, vacuum pressure gauge ball valve, 25, vacuum pump ball valve, 26, vacuum pump, 27, sampling ball valve, 28, sampling port, 29, sampling ball valve, 30, sampling port, 31, artificial insulation defect, 32, grounding Conductive rod, 33, supporting feet, 34, quartz glass observation window, 35, fluorescent optical fiber sensor channel, 36, partial discharge calibrator.

At first introduce the concrete structure of the testing device that the present invention relates to:

Known from device circuit principle and structural schematic diagrams 1 to 4, a multi-sensor joint monitoring experimental device for partial discharge of gas-insulated electrical equipment is mainly composed of a power frequency AC power system, a gas discharge chamber, an artificial insulation defect model, and a multi-sensor joint detection system , mainly including: 1. Power supply voltage regulating console, 2. No partial discharge power frequency test transformer, 3. No partial discharge protection resistor, 4. Power frequency capacitor voltage divider, 5. Coupling capacitor, 6. Detection impedance, 7. . Gas discharge chamber, 8. Artificial insulation defect model, 9. Fluorescence optical fiber sensor, 10. Optical fiber coupler, 11. Ordinary optical fiber, 12. Gas chromatography mass spectrometer, 13. Optical fiber adapter, 14. Photomultiplier tube, 15 , UHF sensor, 16, digital storage oscilloscope high voltage bushing. (Figure 1-4)

The power frequency AC power supply system is composed of a power supply voltage regulating console 1, a power frequency test transformer without partial discharge 2, a protection resistor without partial discharge 3, and a power frequency capacitor voltage divider 4. The power frequency AC mains 220V/50Hz in the laboratory is connected to the input port (output voltage is 0-250V) of the power voltage regulating console 1 (commercially purchased product, capacity is 10kVA) through wires, and the output is regulated by the voltage regulating console. The port is connected to the input port of the non-partial discharge power frequency test transformer 2 (commercially available product, 50kV/10kVA), and the output port (high voltage port) of the no partial discharge power frequency test transformer 2 is connected through the wire through the protective resistor 3 (commercially purchased product , 10kΩ/0.5A), the output of the capacitive voltage divider 4 (commercially available product, 50kV/1000:1, precision level 1.0) is connected in parallel with the gas discharge chamber 7; Regulation provides continuous regulation of power frequency AC voltage to the partial discharge of the insulation defect model electrodes in the gas discharge chamber connected by wires.

From the top to the bottom of the structure, the gas discharge chamber consists of a high-voltage guide rod 17, a high-voltage bushing 18, an ellipsoidal top cover 19, a screw 20, a flange 21, a stainless steel columnar cavity 22, a vacuum pressure gauge ball valve 23, and a vacuum pressure gauge. Table 24. Vacuum pump ball valve 25, vacuum pump 26, sampling ball valve 27, sampling port 28, sampling ball valve 29, sampling port 30, artificial insulation defect 31, grounding conductive rod 32, supporting feet 33, and quartz glass observation window 34. A through hole with a diameter of 200 mm is provided at the center of the ellipsoidal top cover 19, and the high-voltage guide rod 17 and flange 21 wrapped by the polytetrafluoroethylene high-voltage bushing 18 are formed from the top cover through one-time packaging. The through hole of the through hole goes deep into the cylinder body, and the through hole of the top cover is sealed through the flange 21. The port where the high pressure guide rod 17 extends into the cylinder body adopts a thread structure with a total thread length of 20mm and a pitch of 1mm; The upper port of the columnar cavity is annularly fixed with a flange 21 with a diameter of 550 mm and a thickness of 15 mm. It adopts a rectangular sealing groove and an "O"-shaped rubber ring sealing structure. The flange uses 12 screws with a diameter of The screw 20 of 15mm provides enough pressing force that the described ellipsoidal top cover 19 that is 550mm in diameter and 12mm in thickness is fixed on the flange 21 of the stainless steel cylinder to build a sealed chamber; The cavity 22 is made of a cylinder with an inner diameter of 500mm, a thickness of 10mm, and a height of 600mm. The upper end is the detachable ellipsoidal top cover 19, and the lower end is a welded ellipsoidal head. The stainless steel The structure of the columnar cavity 22 can withstand pressures above five atmospheres; dig a through hole with a diameter of 20 mm at the center position of the left side wall of the stainless steel columnar cavity 22 300 mm from the bottom end; weld a A stainless steel pipe with an inner diameter of 20 mm, an outer diameter of 10 mm, and a length of 400 mm. The vacuum pressure gauge 24 is connected to the stainless steel pipe at a distance of 200 mm from the through hole through a vacuum pressure ball valve 23 to monitor the vacuum degree and air pressure of the gas discharge chamber. A sampling ball valve 27 is connected to the stainless steel tube at the 250mm place from the through hole, and the sampling port 28 at the other end of the sampling ball valve is communicated with the steel cylinder through a Teflon air guide tube for inflation; the stainless steel columnar cavity 22 Dig a through hole with a diameter of 20mm on the right side wall at a distance of 300mm from the bottom, weld a stainless steel pipe with an inner diameter of 20mm, an outer diameter of 10mm, and a length of 200mm on the through hole, and connect another stainless steel pipe at a distance of 200mm from the through hole. The sampling ball valve 29 is connected with the sampling port 30, and the other end sampling port 30 of the sampling ball valve 29 is communicated with the gas chromatography-mass spectrometer 12 through a Teflon air duct, and carries out partial discharge decomposition gas sampling; Two quartz glass observation windows 34 with a diameter of 100 mm and a thickness of 6 mm are respectively set at the center positions of the front and rear side walls of the body 22 at a distance of 250 mm from the bottom. Seal and fix with 8 screws 19 with a screw diameter of 15mm, and the development process of partial discharge can be observed through the quartz observation window; a 80mm place is opened directly below the sampling port 30 of the stainless steel columnar cavity 22 15mm optical fiber through hole, through the external 15mm screw to compress the internal rubber ring of the channel to ensure the sealing, forming the fluorescent optical fiber sensor channel 35 to connect the external channel; open one at the center of the bottom cover of the stainless steel columnar cavity 22 12mm Through hole, the ground conductive rod passes through the through hole and is sealed on the bottom cover of the stainless steel column cavity; the end of the ground conductive rod 31 extending out of the cylinder is passed through a copper braid (commercially available, 25mm wide) ) is grounded, and one end in the cylinder cavity adopts a thread structure with a total thread length of 20mm and a pitch of 1mm; the bottom cover of the stainless steel columnar cavity is symmetrical along the outer center of the spherical surface and has an inclination of 10 degrees. Three support feet with a length of 400mm are fixed, and the three support frames are connected with a cross bar at a distance of 100mm from the ground to support the entire test device.

Four typical insulation defect models include conductive rod protrusion defect model (Fig. 4a), insulator surface metal attachment defect model (Fig. 4b), insulator hole/crack defect model (Fig. 4c), and free metal particle insulation defect model (Fig. 4d). The protruding object defect model of the conductive rod uses a needle-plate electrode; the aluminum needle electrode approximates the real central conductive rod of gas-insulated electrical equipment, its diameter is 4mm, and its length is 40mm, wherein the needle electrode starts from the circular end The initial thread length of the first part is 20mm, the length of the needle tip part is 10mm, and the radius of curvature of the tip is 0.4mm; the plate electrode of the stainless steel material approximates the diameter of the plate electrode described in the shell of the real gas-insulated electrical equipment to 120mm, and the thickness is 12mm. The central connecting rod at the bottom end of the plate electrode has a diameter of 4 mm, a length of 25 mm, and a thread length of 15 mm at the lower end. The metal attachment defect model on the insulator surface uses stainless steel plate-plate parallel electrodes of the same size to approximate the electric field distribution in the cavity, and uses a columnar epoxy resin block to approximate the supporting insulator in the gas-insulated electrical equipment. When the electrodes and insulators are glued together, a certain amount of copper shavings is pasted to approximate the pollution defect. The diameter of the plate electrode is 120mm, the thickness is 12mm, the diameter of the upper and lower two electrode connecting rods is 4mm, the length is 25mm, the end thread length is 15mm, and the plate electrode spacing is 25mm; the diameter of the cylindrical epoxy resin is 60mm, and a height of about 25mm; the vertical length of the bonded copper shavings is 15mm, and the width is 1.5mm, and the diameter of the copper shavings is within 100 μm. The insulator hole/crack defect model is simulated by padding two epoxy resin sheets between the cylindrical epoxy resin and the stainless steel plate electrode to form an air gap; the plate electrode has a diameter of 120mm and a thickness of 12mm, and two The diameter of the electrode connecting rod is 4mm, the length is 25mm, the thread length at the end is 15mm, and the plate electrode spacing is about 21mm; the diameter of the cylindrical epoxy resin is 60mm, and the height is 20mm; the thickness of the air gap is 1mm. The free metal particle insulation defect model is simulated by using a stainless steel ball-bowl electrode and an aluminum foil of a certain size placed inside the hemispherical bowl electrode; the diameter of the ball electrode is 30mm, the outer diameter of the bowl electrode is 120mm, and the thickness Both are 2mm, the diameter of the electrode connecting rod of the ball electrode and the bowl electrode is 4mm, the length is 35mm, and the thread length is 20mm; the size of the rectangular aluminum foil is 2mm×2mm.

The multi-sensor joint detection system includes four parts: pulse current method sensor detection system, ultra-high frequency sensor detection system, gas chromatography mass spectrometry detection sensor detection system and fluorescent optical fiber sensor detection system; wherein the pulse current detection sensor is based on IEC60270 parallel detection method, the guide line at the high-voltage port of the gas discharge chamber 7 is connected to the high-voltage port of the coupling capacitor 5 (commercially available product, 120kV/1000pF), and the low-voltage end of the coupling capacitor 5 is connected to the detection impedance 6 (commercially available) through a wire. Purchased product, No. 3) is connected to the digital storage oscilloscope 16, the pulse signal generated by the partial discharge of the insulation defect of the gas discharge chamber is amplified by the detection impedance 6 and then enters the digital storage oscilloscope 16 for display, and is detected by the digital storage oscilloscope 16. The pulse amplitude information of discharge; Described ultra-high frequency sensor detection system is connected to digital storage oscilloscope by cable with the ultra-high frequency microstrip antenna 15 (laboratory customization) that is non-contact with described discharge gas chamber and test power supply system In 16, the partial discharge UHF signal of the artificial insulation defect is detected, and the UHF information of the partial discharge is extracted; the gas chromatography mass spectrometry sensor detection system is connected to the gas outlet of the gas discharge chamber 7 cylinders Part of the Teflon airway was used to collect partial discharge decomposition gas, and ppbv levels of SO ₂ F ₂ , SOF ₂ , and CO ₂ were detected by gas chromatography-mass spectrometry 12 (commercially available products, Shimadzu GC/MS-QP2010Ultra) , CF ₄ , H ₂ S, SO ₂ and other SF ₆ gas partial discharge decomposition gas information; the fluorescent optical fiber sensor detection system is composed of a fluorescent optical fiber sensor placed in the gas discharge chamber through the gas discharge chamber cylinder The fluorescent fiber optic sensor channel on the body comes out and is connected to the fiber coupler, connected to the fiber optic adapter through an ordinary optical fiber, and then connected to a port of the photomultiplier tube, and the other port of the photomultiplier tube is connected to the power supply and the last port is passed through The current is connected to a digital oscilloscope, and the photoelectric information of the partial discharge is detected by the digital oscilloscope.

Example

A multi-sensor joint detection experimental method for partial discharge of gas-insulated electrical equipment. Using the above-mentioned device, the specific steps of performing PD simulation experiments and multi-dimensional partial discharge information collection and analysis on SF ₆ gas-insulated electrical equipment are as follows:

⑴Experimental preparation

①Placing artificial insulation defect model and device dust removal treatment

First, accurately connect each device according to the schematic diagram of the test circuit in Figure 1, and ground all test equipment in turn to ensure the electrical safety of the test; uncover the spherical top cover of the stainless steel columnar cavity 22 of the gas discharge chamber 7 in the test device 19. Use ethanol liquid to clean and wipe the inner wall of the stainless steel cavity 22 and the artificial defect model 31 to remove impurities and dust on the device, and screw the two ends of the artificial defect to the high and low pressure guide rods respectively, and then the spherical top The cover 19 is packaged well; ensure that impurities and dust will not interfere with the entire test;

② Check the air tightness of the test device

First, tighten and close the sampling ball valve 29 and the sampling ball valve 27, open the vacuum pump ball valve 25 and the vacuum pressure gauge ball valve 24 of the device, and after confirming that the valves are opened and closed correctly, open the vacuum pump 26 outside the gas discharge chamber 7, and pass The air filling port of the stainless steel cavity is pumped, and the vacuum tension gauge 23 is observed. When the pointer on the vacuum pressure gauge 23 points to 0-0.01MPa, the vacuum pressure gauge ball valve 24 and the vacuum pump 26 on the device are closed. After standing still for about 24 hours, observe whether the mark on the vacuum pressure gauge 23 changes. If the above-mentioned vacuum pressure indication remains at 0-0.015MPa and the mark hardly changes, it is confirmed that the gas discharge chamber 7 is in a vacuum state. Good air tightness. Open the valve of the purchased SF ₆ gas cylinder and the inlet ball valve 29 of the gas discharge chamber, manually adjust and inject SF ₆ gas into the stainless steel cavity 22 at a constant speed, observe the pressure pointer on the vacuum voltmeter 23 until it reaches 0.35-0.5 MPa, and use the symbol Make a mark on the table with a pen, close the valve of the above-mentioned SF ₆ gas cylinder and the inlet ball valve 29 in sequence, and observe the vacuum pressure gauge 23 after standing for 24 hours. The above-mentioned gas discharge chamber 7 has good air tightness under air pressure, and finally ensures the airtightness and safety of the gas test;

③SF ₆ gas cleaning stainless steel cavity

After completing steps (1)-①②, connect the vacuum pump 26 externally and open the vacuum pump ball valve 25, and vacuumize the above-mentioned stainless steel cavity 22 through the opened vacuum pump ball valve 25. When the vacuum degree indicated on the vacuum pressure gauge 23 is 0-0.01 MPa, close the above-mentioned vacuum pump ball valve 25 and vacuum pump 26 in sequence. Then connect the SF ₆ gas cylinder externally, inject SF ₆ gas into the above-mentioned stainless steel cavity 22 through the gas cylinder gas valve and the sampling ball valve 27, and raise the air pressure value in the stainless steel cavity 22 to within the range of 0.3-0.4MPa, Clean the stainless steel cavity 22, and let it stand for 4-6 hours to fully vaporize and release the decomposition gas and moisture of the _SF6 gas attached to the stainless steel cavity 22 in the previous test; then repeat the above-mentioned vacuuming and injection of _SF6 gas process, so as to ensure that the impurity gas and inherent moisture content in the stainless steel cavity 22 are reduced to the extent that the test results will not be affected;

④SF ₆ gas inflation

After completing (1)-③ steps, connect the SF ₆ gas cylinder externally, inject SF ₆ gas into the stainless steel cavity 22 through the valve of the gas cylinder and the inlet ball valve 27, until the pointer of the vacuum pressure gauge 23 is stable at 0.4MPa , and then close the valve of the SF ₆ gas cylinder and the inlet ball valve 27 in turn; let stand for 4 to 6 hours to make SF ₆ evenly dispersed in the gas discharge chamber;

(2) Conduct power frequency AC SF ₆ gas PD test

①Device inherent PD initial voltage test

Before carrying out the power frequency AC SF ₆ gas PD test, it is necessary to determine the partial discharge level of the device itself through pressurization, that is, the test device is under the same external environmental and geographical conditions as the defect test, to determine the test voltage threshold for the device not to produce PD . Therefore, do not place any defect to carry out the test in step (1). After checking the connection safety of the test circuit, turn on the power supply voltage regulation console 1 to load the power frequency voltage to the device when there is no artificial defect model. Increase the external processing frequency voltage, observe the signal on the digital storage oscilloscope 16 connected to the detection device, once a tiny discharge pulse signal is found, record and define the external applied voltage on the device at this moment as the inherent initial PD of the device Voltage U _g ; After completing the determination of the initial PD voltage value, reduce the applied voltage to 0 and cut off the connection between the input terminal of the power regulator console 1 and the 220V/50Hz mains, and use the grounding rod to test all the voltages in the entire test device. The high-voltage end of the equipment is grounded and discharged; then the vacuum pump ball valve 25 is turned on, and the external vacuum pump 26 is turned on to vacuumize the gas discharge chamber 7. When the vacuum pressure gauge shows that it is below 0.01MPa, the vacuum pumps are sequentially turned off. Ball valve 25 and vacuum pump 26;

②Carry out power frequency AC SF ₆ gas PD test

First open the quartz glass observation window 34 on one side of the gas discharge chamber, and manually connect the needle plate model of the simulated metal protrusion defect in the artificial defect model 31 made through the threaded structure of the grounding conductive rod 32 to it, and pass the grounding conductive rod 32 The adjustment device at the bottom adjusts the distance between the two electrodes of the defect so that the electrodes are closely connected to the two ends of the defect; then install the quartz glass observation window 34 through the connecting flange, seal it with an "O"-shaped rubber gasket and use 12 screws with a diameter of The 15mm screw is compressed and fixed; then the stainless steel cavity 22 is gas-cleaned with SF ₆ , and after this step is completed, continue to pour 0.04MPa SF ₆ gas into the stainless steel cavity 22, and turn on the power regulator console 1 Regulate the power frequency voltage loaded on the artificial defect model 31, slowly increase the voltage, observe the signal on the digital storage oscilloscope 16 connected to the detection device, once a tiny discharge pulse signal is found, record and define the external voltage on the device at that moment. The applied voltage is the initial PD voltage U _st of the device, and based on U _st , set 1.1U _st , 1.2U _st , 1.3U- _st , 1.4U _st , 1.5U _st , 1.6U _st , 1.7U _st , 1.8 Carry out tests with eight applied voltages of power frequency U _st , and ensure that the applied voltage does not exceed the inherent initial PD voltage U _g of the device when setting the applied voltage; continue to adjust the applied voltage of power frequency to 1.2U _st , at 1.2U The artificial insulation defect 31 is subjected to a continuous 96h PD test at a voltage of _st , and the test data is collected every 12 hours; after the continuous 96h PD test, eight sampling data of an artificial insulation defect 31 under the test voltage can be obtained; Reduce the applied voltage to 0 and cut off the connection between the input terminal of the power regulator console 1 and the 220V/50Hz mains, use the grounding rod to discharge the high-voltage end of all equipment in the entire test device to the ground; then turn on the vacuum pump ball valve 25 and open The external vacuum pump 26 vacuumizes the discharge chamber, and when the vacuum pressure gauge shows that it is below 0.01MPa, close the vacuum pump ball valve 25 and the vacuum pump 26 in sequence and disconnect the vacuum pump 26;

Then use SF ₆ to carry out gas cleaning to described stainless steel cavity 22, after finishing this step, continue to rush into the SF ₆ gas of 0.04MPa in the stainless steel cavity, adjust the power frequency externally applied voltage to increase to 1.3U _st , at a voltage of 1.3U _st , conduct a continuous 96h PD test on the artificial insulation defect 31, and collect test data every 12 hours; after a continuous 96h PD test, an artificial insulation defect 31 can be obtained at this test voltage The following eight sampling data; reduce the applied voltage to 0 and cut off the connection between the input terminal of the power regulator console 1 and the 220V/50Hz mains, and use the grounding rod to discharge the high-voltage terminals of all equipment in the entire test device to the ground; then Turn on the vacuum ball valve, turn on the external vacuum pump 26 to vacuumize the discharge chamber, observe the vacuum pressure gauge 23 and when it shows that it is below 0.01MPa, close the vacuum pump ball valve 25 and vacuum pump 26 in sequence and disconnect the vacuum pump 26 ;

Repeat the test steps of air washing and pressurization in this way to complete eight power frequency external applied voltages of 1.1U _st , 1.2U _st , 1.3U _st , 1.4U _st , 1.5U _st , 1.6U _st , 1.7U _st , and 1.8U _st Based on the experimental data, the researchers extracted and characterized the PD intensity according to the data information obtained from the content of various SF ₆ decomposition gases and gas production rates, ultra-high frequency signals, and optical signals of fluorescent optical fibers under eight test voltages. To study the mechanism of SF ₆ gas PD decomposition.

③Pulse current detection

Adopt the parallel connection method in the IEC60270 method to measure the PD pulse voltage signal, as shown in Figure 5, a partial discharge calibrator 36 is connected in parallel with the artificial insulation defect 31 in the gas discharge chamber 7, through the partial discharge calibrator 36 generates a pulse signal with a known discharge amount at the two poles of the artificial insulation defect 31, and the pulse voltage peak value U at both ends of the detection impedance 6 can be measured through the connected digital storage oscilloscope 16, and the pulse voltage amplitude U is different from the apparent The discharge quantity Q has a linear relationship, so the apparent discharge quantity Q is calculated based on the peak value U of the pulse voltage measured by the pulse current method, as shown in Figure 6, the linear relationship between the pulse voltage amplitude U and the apparent discharge quantity Q;

④ UHF sensor detection

Before pressurizing with the power supply voltage regulating console 1, the ultra-high frequency sensor 15 is fixed and placed externally at the position facing the artificial insulation defect 31, and the background noise is recorded on the digital storage oscilloscope 16 through the ultra-high frequency sensor to understand the noise level of the experimental environment, Then in the 96h continuous PD test process, the digital storage oscilloscope 16 is connected to the ultra-high frequency signal every 11 to 12 hours, and the PD signal acquisition of the power frequency cycle is carried out, and the sampling frequency of the digital storage oscilloscope 16 is set to 50MS/s. The time resolution is 2ms/div, and the number of sampling points is 1M, that is, the time length of 20ms. According to experience, when the partial discharge signal on the digital oscilloscope is judged to be stable, the researchers start to collect 2500 power frequency cycle discharge waveforms under each test voltage data, and at the same time access the phase information of the power frequency reference voltage in the digital storage oscilloscope 16 through the cable drawn out from the capacitive voltage divider 4 .

⑤Fluorescent fiber optic sensor detection

During the 96h continuous PD test process, the digital storage oscilloscope 16 is connected to the PD information collection of the fluorescent optical fiber sensor 9 every 11-12h, and the sampling frequency of the digital storage oscilloscope 16 is set to 50MS/s, and the time resolution is 2ms/s. div, the number of sampling points is 1M, i.e. 20ms time length, start to collect 2500 power frequency cycle discharge waveform data under each test voltage, and simultaneously access the acquisition work in the digital storage oscilloscope 16 through the cable drawn on the capacitive voltage divider 4 phase information of the frequency reference voltage.

⑥ Collection and component detection of discharge gas

During the 96h continuous PD test, after 12h of discharge, the applied voltage is reduced to 0 and the connection between the input terminal of the power regulator console 1 and the 220V/50Hz mains is cut off, and the grounding rod is used to apply high voltage to all the equipment in the entire test device Then connect the sampling bag to the sampling port 30 and turn on the sampling ball valve 29 to collect the discharge gas, and close the sampling ball valve 29 after completion; then adjust the voltage to the next test voltage value to continue the PD test, and then continue the PD test after 12 hours. Carry out a discharge gas collection and go back and forth like this;

This device uses Shimadzu GC/MS-QP2010Ultra gas chromatography-mass spectrometer 12 for qualitative and quantitative analysis of the discharge gas collected each time; the gas components are made of a special film with a film thickness of 8um, an inner diameter of 0.32mm, and a length of 60m. Capillary column separation and detection by MSD detector; this method uses 99.999% high-purity He as the carrier gas, and the working conditions are: the temperature of the column oven is kept at a constant temperature of 35°C for 7.5min, and the temperature is raised to 70°C/min at a rate of 70°C/min Hold at 105°C for 10 minutes, raise the temperature to 250°C at a rate of 100°C/min and hold for 3.5 minutes, the temperature of the injection port is 220°C, the pressure flow control mode is 55kPa, the total flow rate is 16.3mL/min, and the column flow rate is 1.21mL /min, the linear velocity is 28cm/sec, the purge flow rate is 3mL/min, the split ratio is 10, the ion source temperature is 200°C, the chromatographic mass spectrometer interface temperature is 220°C, the solvent delay time is 0min, the micro scan width is 0u, and the detection The instrument voltage is 0kV; the ionization method is electric bombardment ionization; the acquisition method is SIM quantitative analysis; the scanning interval time is 0.3s; this method can realize the decomposition components of SF ₆ under PD: CF ₄ , CO ₂ , SO ₂ F ₂ , SOF ₂ , H ₂ S, SO ₂ , CS ₂ and other gases and detect their concentrations effectively; as shown in Figure 7, it is the total ion chromatogram TIC of the mixed sample gas detected by this method, as can be seen from Figure 7, CF _4. The retention times of CO ₂ , SO ₂ F ₂ , SOF ₂ , H ₂ S, SO ₂ , and CS ₂ are 4.356min, 4.853min, 5.096min, 5.47min, 6.099min, 7.154min, and 18.414min, respectively, so the The method realizes the effective separation of the above-mentioned multiple gases.

The gas sample obtained by sampling is carried by the high-pressure carrier gas (helium used in this paper) that has been decompressed and purified and flows into the chromatographic column to achieve effective separation of different components. An electrical signal is obtained for the content of the reaction components. The function of the detector is to convert the proportion of gas components into electrical signal output, and the detection report output and displayed by the data processing workstation is called a chromatogram. Obviously, the size of the peak area of the chromatogram is the size of the electrical signal output by the detector, which is proportional to the component content. At the same time, through the chromatographic system under the same conditions, the retention time of the same substance with different concentrations in the detector remains unchanged, so the retention time of the standard gas of the measured product can be detected in advance, and the measured product can be quantitatively calibrated using the following formula:

$\frac{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; c</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}$

Among them, c _s and ci represent the concentrations of the measured _i -th gas component and its standard gas, respectively, A _s and A _i are the chromatographic peak areas, and K _i is the absolute correction factor. As shown in Figure 9-Figure 14, CF ₄ , CO ₂ , SO ₂ F ₂ , SOF ₂ , H ₂ S, SO ₂ obtained by quantitatively calibrating the gas chromatography-mass spectrometer using the standard gases configured in Table 1 , CS ₂ calibration curve.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (6)

1. a gas insulated electric apparatus shelf depreciation multisensor joint-detection experimental technique, is characterized in that, specifically comprise:

The step of Preparatory work of experiment: first place artificial insulation defect model and to device dust removal process, then check test device impermeability, then adopts purge of gas stainless steel cavity, finally carries out SF ₆gas inflated;

SF under industrial frequency AC condition ₆the step of the joint-detection simulated experiment of gas PD signal, specifically comprises:

Test experience one, inherent shortcoming is tested: carry out SF ₆gas PD test first will be tested the intrinsic PD characteristic of whole test unit, and under the same test conditions, time by simulation prosthetic defect model, the threshold value of the trial voltage of shelf depreciation does not occur test unit; (1) step is completed under not placing manual simulation's defect condition, after the connection safety of check test circuit, power-frequency voltage on device when power-on is carried in prosthetic defect model by the regulation and control of pressure regulation platform, along with the additional power-frequency voltage of increase slowly, observe the signal be connected on the digital storage oscilloscope of pick-up unit, once find to occur small discharge pulse signal, to record and on the device defining this moment, applied voltage is the intrinsic initial PD voltage U of device _g; Complete after initial PD magnitude of voltage determines work, applied voltage is reduced to 0 and cutting-off pressure-regulating control desk input end and the connection of 220V/50Hz civil power, with ground rod, all devices high-pressure side ground connection in whole test unit is discharged; Then conducting vacuum pump ball valve, opening external vacuum pump will carry out in described arc chamber vacuumizing process, observe pressure vacuum gauge its when being shown as below 0.01MPa, the vacuum pump ball valve described in orderly close-down and vacuum pump;

Test experience two, industrial frequency AC SF ₆gas PD tests: the quartz glass watch window first opening gas discharge chamber side, manually the defects simulation model made is connected with it by the helicitic texture of ground connection conducting rod, regulates the distance between defect two electrodes to make electrode and defect two ends compact siro spinning technology by the regulating device bottom ground connection conducting rod; Then quartz glass is loaded onto by acting flange, also fix with the screw in compression that 12 screw diameters are 15mm with " O " shape rubber seal; Then SF is used ₆purge of gas is carried out to described stainless steel cavity, after completing this step, continues the SF pouring 0.04MPa in stainless steel cavity ₆gas, power-frequency voltage on device when power-on is carried in artificial defect model by the regulation and control of pressure regulation platform, observe the signal be connected on the digital storage oscilloscope of pick-up unit, once find to occur small discharge pulse signal, to record and on the device defining this moment, applied voltage is the initial PD voltage U of device _st, with U _stbe decided to be benchmark setting 1.1U _st, 1.2U _st, 1.3U _st, 1.4U _st, 1.5U _st, 1.6U _st, 1.7U _st, 1.8U _steight power frequency applied voltages carry out test, and the trial voltage being applied to defect model should not exceed the intrinsic initial PD voltage U of device _g; Continue to regulate power frequency applied voltage to increase to 1.2U _st, at 1.2U _stvoltage under artificial insulation defect carried out to the PD test of continuous 96h, every 12h carries out a test data acquisition; Eight sampled datas of a kind of artificial insulation defect under this trial voltage can be obtained after the PD test of continuous 96h; Applied voltage is reduced to 0 and the connection of cutting-off pressure-regulating control desk input end and 220V/50Hz civil power, uses ground rod to all devices high-pressure side ground connection electric discharge in whole test unit; Then conducting Vacuum ball valve, opening external vacuum pump will carry out in described arc chamber vacuumizing process, observe pressure vacuum gauge its when being shown as below 0.01MPa, the vacuum pump ball valve described in orderly close-down and vacuum pump also disconnect;

Then SF is used ₆purge of gas is carried out to described stainless steel cavity, completes the SF that this step continues to pour 0.04MPa afterwards in stainless steel cavity ₆gas, regulates power frequency applied voltage to increase to 1.3U by pressure regulation platform _st, at 1.3U _stvoltage under artificial insulation defect carried out to the PD test of continuous 96h, every 12h carries out a test data acquisition; Eight sampled datas of a kind of artificial insulation defect under this trial voltage can be obtained after the PD test of continuous 96h; Applied voltage is reduced to 0 and the connection of cutting-off pressure-regulating control desk input end and 220V/50Hz civil power, uses ground rod to all devices high-pressure side ground connection electric discharge in whole test unit; Then conducting Vacuum ball valve, opening external vacuum pump will carry out in described arc chamber vacuumizing process, observe pressure vacuum gauge its when being shown as below 0.01MPa, the vacuum pump ball valve described in orderly close-down and vacuum pump also disconnect;

The test procedure of repetition gas washing inflating pressure like this, completes 1.1U _st, 1.2U _st, 1.3U _st, 1.4U- _st, 1.5U _st, 1.6U _st, 1.7U _st, 1.8U _sttest figure under eight power frequency applied voltages; Based on these experimental study data, researchist is according to various SF under eight kinds of trial voltages ₆the data message that the light signal of decomposition gas content and gas production rate, ultra-high frequency signal, fluorescence optical fiber obtains extracts the characteristic quantity characterizing PD intensity, research SF ₆the mechanism that gas PD decomposes;

Test experience three, pulse current detects: adopt the multiple process in IEC60270 method to measure PD pulse voltage signal, by in parallel for indoor to a shelf depreciation prover and described gas discharge artificial insulation defect, the known pulse signal of discharge capacity is produced at insulation defect the two poles of the earth by described shelf depreciation prover, the crest value of impulse voltage U at described detection resistance two ends can be recorded by the described digital storage oscilloscope connected, and pulse voltage amplitude U and Apparent discharge magnitude Q is linear, therefore the crest value of impulse voltage U recorded according to pulse current method calculates Apparent discharge magnitude Q,

Test experience four, uhf sensor detects: to be fixed by uhf sensor before with pressure regulator pressurization external just to the position of insulation defect, by uhf sensor at digital storage oscilloscope record ground unrest, understand experimental situation noise level, then in the continuous P D process of the test of 96h, during every 11 ~ 12h, digital storage oscilloscope is accessed ultra-high frequency signal, carry out the PD signals collecting of power frequency period, arranging oscillographic sample frequency is 50MS/s, temporal resolution is 2ms/div, sampling number is 1M, i.e. 20ms time span, researchist rule of thumb judge described in digital oscilloscope on local discharge signal stablize time, start to gather lower 2500 the power frequency period discharge waveform data of each trial voltage, and the cable simultaneously by capacitive divider is drawn accesses the phase information of the acquisition power frequency reference voltage in oscillograph,

Test experience five, fluorescent optical fiber sensor detects: in the continuous P D process of the test of 96h, during every 11 ~ 12h, digital storage oscilloscope is accessed fluorescence optical fiber collection, arranging oscillographic sample frequency is 50MS/s, temporal resolution is 2ms/div, sampling number is 1M, i.e. 20ms time span, start to gather lower 2500 the power frequency period discharge waveform data of each trial voltage, and the cable simultaneously by capacitive divider is drawn accesses the phase information of the acquisition power frequency reference voltage in oscillograph;

Test experience six, the collection of discharge gas and detection: in the continuous P D process of the test of 96h, after electric discharge 12h, applied voltage is reduced to 0 and the connection of cutting-off pressure-regulating control desk input end and 220V/50Hz civil power, uses ground rod to all devices high-pressure side ground connection electric discharge in whole test unit; Then sampler bag to be connected on thief hatch and conducting sampling ball valve, to carry out the collection of a discharge gas, after completing, close sampling ball valve; Then regulation voltage rises to next trial voltage value and proceeds PD test, carries out a discharge gas collection more and so forth after 12h.

2. a kind of gas insulated electric apparatus shelf depreciation multisensor joint-detection experimental technique according to claim 1, it is characterized in that, in described test experience six, gas chromatograph-mass spectrometer is adopted to be that Shimadzu GC/MS-QP2010Ultra carries out qualitative and quantitative analysis to each discharge gas gathered, , gas composition is 8um by thickness, and internal diameter is 0.32mm, and length is the special capillary column separation of 60m, is detected by MSD detecting device, this method adopts high-purity He of 99.999% as carrier gas, condition of work is: post case temperature mode is that constant temperature 35 DEG C keeps 7.5min, 10min is kept with the ramp to 105 of 70 DEG C/min DEG C, 3.5min is kept with the ramp to 250 of 100 DEG C/min DEG C, injector temperature is 220 DEG C, pressure flow hybrid control mode, pressure is 55kPa, total flow is 16.3mL/min, post flow is 1.21mL/min, linear velocity is 28cm/sec, purge flow rate is 3mL/min, split ratio is 10, ion source temperature is 200 DEG C, chromatographic mass spectrometry interface temperature is 220 DEG C, the solvent delay time is 0min, micro scanning width 0u, detector voltage 0kV, ionization mode is electricity bombardment ionization, acquisition mode is SIM quantitative test, sweep interval 0.3s, the method can realize SF ₆decomposition components CF under PD ₄, CO ₂, SO ₂f ₂, SOF ₂, H ₂s, SO ₂, CS ₂etc. multiple gases effective separation and detect its concentration,

The gas sample that sampling obtains by through decompression, high pressure carrier gas (adopting helium herein) after purified treatment with flowing into chromatographic column thus realizing effective separation of different component, by selecting suitable detecting device, the electric signal of reactive component content can be obtained in terminal; The effect of detecting device gas composition content accounting is converted to electric signal to export, and to export and the examining report shown is called as chromatogram through data processing stations; Obviously, the peak area size of chromatogram is detecting device and exports electric signal size, relation proportional with component concentration; Meanwhile, by the chromatographic system of similarity condition, the same substance retention time in a detector of variable concentrations is constant, therefore can detect its retention time of calibrating gas of tested product in advance, utilize following formula to carry out quantitatively calibrating to tested product:

$\frac{c_i}{c_s}=\frac{A_i}{A_s}=K_i{A}_i$

Wherein, c _sand c _irepresent respectively survey the concentration of i-th kind of gas composition and gas thereof, A _sand A _ithen be respectively chromatographic peak area, K _ifor the Absolute Calibration factor.

3. a kind of gas insulated electric apparatus shelf depreciation multisensor joint-detection experimental technique according to claim 1, it is characterized in that, the concrete operations of the artificial insulation defect model of described placement and device dust removal process are: first, schematic diagram according to hookup accurately connects each device, successively ground connection is carried out to all testing equipments, guarantee the electrical security tested; Open the spherical top cover of the stainless steel cylindrical cavities of the gas discharge chamber in test unit, ethanol liquid is adopted to carry out cleaning wiping to the inwall of stainless steel cavity and artificial defect model, impurity dust on removal device, artificial defect two ends are twisted with high-low pressure guide rod respectively and is connected together, then dome cap seal is installed; Guarantee that impurity dust can not produce disturbing effect to whole test.

4. a kind of gas insulated electric apparatus shelf depreciation multisensor joint-detection experimental technique according to claim 1, it is characterized in that, the bubble-tight concrete operations of described check test device are: first, open the vacuum pump that test unit outreaches, bled by the inflation inlet of stainless steel cavity, observe vacuum meter, Vacuum ball valve during pointed 0 ~ 0.01MPa on pressure vacuum gauge on stopping device and vacuum pump, mark on pointer gauge with marking pen, observe mark on pressure vacuum gauge after static 24 hours whether to change, if above-mentioned pressure vacuum gauge registration still remains on 0 ~ 0.015MPa and mark is almost unchanged, under then confirming this device vacuum state, impermeability is good, open the SF purchased ₆the valve of gas cylinder and the air inlet ball valve of gas discharge chamber, manual adjustments air valve at the uniform velocity injects SF in stainless steel cavity ₆gas, on observation Vacuum-Volts table, air pressure pointer is to 0.4 ~ 0.5MPa, and marks on table with marking pen, closes above-mentioned SF successively ₆the valve of gas cylinder and air inlet ball valve, standing pressure vacuum gauge of observing after 24 hours still refers at 0.4 ~ 0.5MPa when pointer and marks almost unchanged, shows that described gas discharge chamber's air pressure seal performance is intact, finally guarantees the security of gas test.

5. a kind of gas insulated electric apparatus shelf depreciation multisensor joint-detection experimental technique according to claim 1, it is characterized in that, the concrete operations of employing purge of gas stainless steel cavity are: first, connect vacuum pump outward, by the vacuum pump ball valve opened, process is vacuumized to above-mentioned stainless steel cavity, when the vacuum tightness of the instruction on pressure vacuum gauge is 0 ~ 0.01MPa, close above-mentioned vacuum pump ball valve and vacuum pump successively; Then SF is connected outside ₆gas cylinder, injects SF by gas cylinder air valve and sample introduction ball valve to above-mentioned stainless steel cavity ₆gas, rises within the scope of 0.3 ~ 0.4MPa by described stainless steel cavity internal gas pressure value, cleans described stainless steel cavity, leaves standstill the SF that 4 ~ 6h makes attachment in the previous test of stainless steel cavity ₆the decomposition gas of gas and moisture fully gasify release; Then above-mentioned vacuumizing and inject SF is repeated ₆gas process, thus to ensure in stainless steel cavity that foreign gas and inherent moisture content drop to can not influential degree to test findings.

6. a kind of gas insulated electric apparatus shelf depreciation multisensor joint-detection experimental technique according to claim 1, is characterized in that, adopts SF ₆the concrete operations of gas inflated are: first, connect SF outward ₆gas cylinder, injects SF by the valve of gas cylinder and air inlet ball valve to described stainless steel cavity ₆gas, till gaseous tension list index is stabilized in 0.4MPa, then closes described SF successively ₆the valve of gas cylinder and air inlet ball valve; Leave standstill and make SF in 4 ~ 6h hour ₆be dispersed in gas discharge indoor.