Experimental device and method for researching partial discharge aging mechanism of insulating material

Abstract

The invention relates to an experimental device and method for studying the partial discharge aging mechanism of an insulating material, and belongs to the technical field of insulating materials. Comprising a multifunctional closed cavity, a high-voltage circuit, a detection loop and a monitoring sensor, and can accurately control the environment atmosphere, the discharge gap and the discharge voltage, thereby simulating the actual complex operation condition of an insulating material under the high-voltage condition, and monitoring the light intensity, the discharge amount and the discharge energy in the discharge process. The device can obtain solid residues of an insulating material under different discharge conditions and collect gas and liquid products. The analysis method not only considers the partial discharge instantaneous heat effect, but also covers the comprehensive effects of active products, ultraviolet radiation and the like in the partial discharge process, so that the aging mechanism of the insulating material under the partial discharge effect is comprehensively analyzed.

Description

Technical Field

[0001] The present invention relates to an experimental device and method for studying the partial discharge aging mechanism of insulating materials, and is particularly suitable for studying the aging mechanism of the constituent materials of high-voltage insulating equipment such as composite insulators under partial discharge conditions, and belongs to the technical field of insulating materials. Background Art

[0002] With the development of the electric power industry, composite insulators are increasingly widely used in high-voltage transmission lines and power equipment due to their light weight, high mechanical strength and strong pollution resistance. However, during operation, composite insulators are often affected by partial discharge, especially under high voltage and high temperature and humidity conditions, which leads to the gradual deterioration of their insulation and mechanical properties, and even serious accidents such as radial fracture or axial internal breakdown. Partial discharge refers to the incomplete electrical breakdown phenomenon that occurs in a local area of ​​electrical insulation equipment, such as the local area at the interface between the core rod and the sheath of a composite insulator. The partial discharge process involves a variety of complex microscopic processes such as transient thermal effects and active free radical chemical reactions, which not only cause the degradation of insulating materials, but also their discharge products may cause long-term secondary degradation of surrounding materials, thereby causing further aging and performance degradation of insulating materials. With the increasing number of high-voltage insulation equipment such as composite insulators in practical applications, it is particularly important to study the partial discharge characteristics and aging mechanisms of their constituent materials in order to extend the life of materials and improve equipment reliability.

[0003] At present, the research on the aging mechanism of high-voltage insulation equipment such as composite insulators at home and abroad mainly adopts a method combining direct pressure aging and material aging characteristics detection. Although these experimental devices and analysis methods can reveal the high-voltage aging characteristics of composite insulator materials to a certain extent and discover external factors that may cause aging or even failure of insulation equipment, they cannot reveal the microscopic mechanism of the aging process of insulation materials, especially the in-depth analysis of the changes in the microstructure of materials, the degradation reaction mechanism and its influence on insulation performance under the possible partial discharge. In addition, the existing insulation material aging experimental devices and experimental methods have certain limitations in simulating actual partial discharge effects and environmental conditions, and it is difficult to fully reflect the effects and mechanisms of the partial discharge process on insulation materials such as composite insulators.

[0004] Therefore, it is of great theoretical and practical significance to develop an experimental device that can systematically study the aging mechanism of the materials of high-voltage insulation equipment such as composite insulators under partial discharge, and to provide a corresponding analysis method. This device and method can not only simulate the partial discharge effect in actual operation, but also deeply analyze the microscopic mechanism of partial discharge aging of materials, reveal the chemical reaction process of material degradation, and thus provide a scientific basis for improving the service life and reliability of high-voltage insulation materials. Summary of the invention

[0005] The present invention aims to solve the key technical problems in the study of the partial discharge aging mechanism of high-voltage insulating materials and develop an experimental device and method for studying the partial discharge aging mechanism of insulating materials.

[0006] The experimental device of the present invention includes a multifunctional closed cavity, a high-voltage circuit, a detection loop and a monitoring sensor, which can accurately control the ambient atmosphere, the discharge gap and the discharge voltage, thereby simulating the actual complex operating conditions of the insulating material under high-voltage conditions, and monitoring the light intensity, discharge amount and discharge energy during the discharge process. The device can obtain the solid residue of the insulating material under different discharge conditions and collect gas and liquid products.

[0007] The analysis method of this experimental device not only considers the transient thermal effect of partial discharge, but also covers the comprehensive effects such as active products and ultraviolet radiation in the partial discharge process, so as to comprehensively analyze the aging mechanism of insulating materials under the action of partial discharge. The basic pyrolysis reaction path of insulating materials under the transient thermal effect of discharge is analyzed by pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) coupling technology. On the basis of this analysis result, a discharge experiment is carried out on insulating materials using a multifunctional closed chamber device. Advanced analytical testing technology is applied to systematically analyze the changes in chemical functional groups of solid residues and the composition of gas and liquid products, and study the degradation reaction mechanism of insulating materials under the comprehensive effect of discharge. This discharge experimental device not only covers the transient thermal effect, but also considers the influence of active products (such as hydroxyl radicals, nitroxide radicals, ozone) and ultraviolet radiation generated by discharge. By combining the PY-GC-MS coupling technology and the comprehensive analysis method of discharge experiments, the degradation reaction path of insulating materials under the comprehensive effect of discharge is fully revealed.

[0008] Through the experimental device and analysis method, the present invention can fully reveal the aging mechanism of high-voltage insulating materials under the action of partial discharge, provide a scientific basis for the modification and optimization of materials, thereby extending the service life of insulating materials and improving the reliability of equipment.

[0009] The specific technical solution provided by the present invention is:

[0010] The invention provides an experimental device for studying the partial discharge aging mechanism of insulating materials, and builds an experimental platform with controllable discharge conditions and collectable products.

[0011] It includes: power supply, closed discharge chamber, discharge quantity detection branch, atmosphere setting system and gas collection system.

[0012] When in the discharge test state, the power supply is connected to grounding device 1 and to the input of the isolation filter transformer. The output of the isolation filter transformer is connected to the input of the no partial discharge test transformer. The probe end of the high-voltage probe is mounted on the high-voltage end of the no partial discharge test transformer, and the ground end of the high-voltage probe is connected to the ground end of the no partial discharge test transformer, and finally connected to grounding device 2. The signal output of the high-voltage probe is connected to channel 1 CH1 of the oscilloscope through a coaxial cable analog signal line 1. The high-voltage end of the no partial discharge test transformer is connected to the head end of the current limiting resistor, and the ground end of the no partial discharge test transformer is connected to grounding device 2.

[0013] When in the discharge experiment state, the upper electrode rod of the closed discharge chamber is connected to the tail end of the current limiting resistor, and the lower electrode rod of the closed discharge chamber is connected to the grounding device 2. In the closed discharge chamber, the precision slide is mechanically connected to the upper electrode rod. When the handle of the precision slide is adjusted, the upper electrode rod can move up and down, and the height value of the upper electrode rod relative to the lower surface of the organic glass upper cover is displayed on the reading window of the precision slide. The upper electrode rod and the organic glass upper cover are connected by a cylinder to ensure the sealing. The organic glass upper cover is connected to the organic glass lower chamber by a flange structure, and a rubber sealing ring is provided to ensure the sealing of the closed discharge chamber. The upper electrode rod and the upper electrode disk are connected by threads, and the lower electrode rod and the lower electrode disk are also connected by threads. The upper electrode disk and the lower electrode disk are arranged relative to each other, and the edges of the upper electrode disk and the lower electrode disk are designed with rounded corners to prevent arcing and avoid direct discharge between metal plates rather than discharge between insulating materials. In order to prevent the strong oxidizing substances generated by the discharge from reacting with the components in the closed discharge chamber and being consumed, thereby causing inaccurate product statistics, the upper electrode rod, upper electrode disk, lower electrode disk and lower electrode rod are all plated with titanium to ensure chemical stability. In addition, the lower surface of the plexiglass upper cover and the inner surface of the plexiglass lower chamber are covered with inorganic glass to increase chemical stability. The upper sample is processed, and its inner diameter is the same as the outer diameter of the upper electrode disk. The two are fixedly connected by a tight fit. The lower sample and the lower electrode disk are also fixedly connected by a tight fit to avoid the use of glue and other materials to introduce additional impurities. During the discharge experiment, discharge will occur in the air gap between the upper sample and the lower sample to simulate the actual partial discharge phenomenon. By adjusting the handle of the precision slide, the air gap spacing between the upper sample and the lower sample can be accurately controlled to simulate the different defect sizes in the high-voltage insulation equipment under operating conditions. Inside the closed discharge chamber, facing the discharge gap, a light sensor is installed to monitor the light intensity of the plasma channel during the discharge process. The optical sensor is connected to the oscilloscope channel 2 CH2 in turn through the aviation plug conversion connector 1, the coaxial cable interface 2 and the coaxial cable analog signal line 2. The closed discharge chamber is also equipped with an ambient air pressure, temperature and humidity multi-in-one sensor, and the signal is transmitted to the comprehensive data acquisition host computer through the aviation plug conversion connector 2 and the digital signal line 1. The aviation plug conversion connector 1, the aviation plug conversion connector 2 and the charging and discharging quick plug valve interface are all embedded and installed in the organic glass cover to ensure the sealing of the closed discharge chamber.

[0014] When in the discharge experiment state, the head end of the discharge detection branch is connected to the upper electrode rod of the closed discharge chamber, and the tail end of the discharge detection branch is connected to the grounding device 2. Specifically, the head end of the coupling capacitor in the discharge detection branch is connected to the upper electrode rod of the closed discharge chamber, the tail end of the coupling capacitor is connected to the head end of the RLC detection impedance, and the tail end of the RLC detection impedance is connected to the grounding device 2. The output signal of the RLC detection impedance outputs a voltage signal through the internal mutual inductance coil, and the voltage signal is transmitted to the channel 3 CH3 of the oscilloscope through the coaxial cable interface 2 and the coaxial cable analog signal line 3. The oscilloscope transmits it to the comprehensive data acquisition host computer through the digital signal line 2.

[0015] When in the atmosphere setting state, the gas charging and discharging quick-plug valve interface installed on the organic glass upper cover in the closed discharge chamber is connected to the atmosphere setting system. Specifically, the interface of the gas cylinder is connected to the first joint of the three-way quick-plug connector 1 through the air pipe 1 and the air pipe valve 1, the interface of the vacuum pump 1 is connected to the second joint of the three-way quick-plug connector 1 through the air pipe 2 and the air pipe valve 2, and the gas charging and discharging quick-plug valve interface is connected to the third joint of the three-way quick-plug connector 1 through the air pipe 3.

[0016] When in the gas collection state, the gas charging and discharging quick-plug valve interface installed on the plexiglass upper cover in the closed discharge chamber is connected to the gas collection system. Specifically, a small vacuum pump is connected to the first joint of the negative pressure box to extract the air in the negative pressure box to create a negative pressure environment. The air bag placed inside the negative pressure box is connected to the second joint of the negative pressure box through trachea four, and at the same time, the second joint of the negative pressure box is connected to the first joint of the three-way quick-plug connector two through trachea five and trachea valve three. Vacuum pump two is connected to the second joint of the three-way quick-plug connector two through trachea six and trachea valve four. The gas charging and discharging quick-plug valve interface is connected to the third joint of the three-way quick-plug connector two through trachea seven.

[0017] When in the state of calibrating discharge, on the basis of the wiring method of the discharge experiment state, the power supply is disconnected from the circuit at the same time, and the calibration pulse generator is connected to both ends of the test object. Specifically, the positive output terminal of the calibration pulse generator is connected to the upper electrode rod of the closed discharge chamber, and the negative output terminal of the calibration pulse generator is connected to the lower electrode rod of the closed discharge chamber. The rest of the wiring method remains unchanged from the wiring method of the discharge experiment state.

[0018] Using the above device, the present invention provides an experimental method for studying the partial discharge aging mechanism of insulating materials, comprising the following steps:

[0019] S1. Determine the basic pyrolysis reaction mechanism of the insulating material under the action of discharge thermal effect. Carry out PY-GC-MS transient thermal analysis on the high-voltage insulating material to be analyzed to analyze its thermal degradation reaction products and mechanism under the transient high temperature effect of partial discharge. Based on this research, further research on the degradation reaction mechanism of the comprehensive discharge effect is planned.

[0020] S2. Process two samples of insulating materials to be analyzed so that they can completely cover the surface and side areas of the electrode disk. Install the upper sample and the lower sample tightly on the upper electrode disk and the lower electrode disk respectively. Fix the upper electrode disk and the lower electrode disk on the upper electrode rod and the lower electrode rod respectively by threaded connection. Then, connect the plexiglass upper cover to the plexiglass lower chamber through a flange and fix it with bolts to ensure the sealing of the closed discharge chamber.

[0021] S3. According to the specific research objectives, set the atmosphere in the closed discharge chamber. Complete the gas pipeline connection according to the description in the experimental device. First, close the valve of the gas cylinder itself, open the valves of the gas pipe valve 1, gas pipe valve 2 and the valve of the gas charging and discharging quick plug valve interface. Start vacuum pump 1 to extract the air in gas pipe 1, gas pipe 2, gas pipe 3 and the closed discharge chamber. Observe the air pressure reading of the ambient air pressure, temperature and humidity multi-in-one sensor through the comprehensive data acquisition host computer. When the air pressure drops to a stable value, close the gas pipe valve 2 and stop the vacuum pump 1. Then, open the valve of the gas cylinder itself, fill the required gas into the closed discharge chamber according to the set amount or air pressure ratio, and adjust the required humidity environment according to the experimental purpose. A dry environment with a relative humidity close to 0% RH can be created by placing silica gel desiccant and molecular sieve in the closed discharge chamber, a semi-humid environment with different relative humidity can be created by placing inorganic glass culture dishes containing different types of saturated ion solutions, and a humid environment with a relative humidity close to 100% can be created by placing inorganic glass culture dishes containing deionized water. Finally, close the valve of the quick-plug valve interface for charging and discharging gas, close the valve of the gas cylinder itself, disconnect the connection between gas pipe three and the quick-plug valve interface for charging and discharging gas, and complete the atmosphere environment setting in the closed discharge chamber.

[0022] S4. Calibrate the proportional relationship between the output voltage and the discharge amount of the RLC detection impedance. Complete the connection of the high-voltage circuit and the signal detection circuit according to the description in the test device. Start the calibration pulse generator, output the pulse signal, and inject a certain amount of charge into the circuit where the sample is located. Set the output calibration charge amount to q c (pC), record the pulse voltage amplitude u of oscilloscope channel three CH3 c (mV), and obtain the calibration coefficient K = u c / q c When the discharge experiment is carried out formally, the pulse voltage amplitude u of oscilloscope channel 3 CH3 is detected and recorded. m(mV), divided by the calibration coefficient K, the discharge amount q of each discharge can be obtained m (pC).

[0023] S5. Apply high voltage to the insulating material in the closed discharge chamber to formally carry out the discharge experiment. Adjust the console knob of the non-partial discharge test transformer and observe the voltage average value of oscilloscope channel one (CH1) until the required set value is reached. Start the comprehensive data acquisition host computer and regularly record the analog signals output by the high-voltage probe, optical sensor, and RLC detection impedance read by the oscilloscope, as well as the digital signals directly output by the ambient air pressure, temperature and humidity all-in-one sensor. The analog signal includes the transformer output voltage output by the high-voltage probe, the discharge light pulse intensity output by the optical sensor, and the discharge pulse voltage signal output by the RLC detection impedance. Based on the discharge pulse voltage signal waveform output by the RLC detection impedance, the discharge amount q of each discharge can be calculated. m (pC), calculated as q m =u c / K. On this basis, the transformer output voltage effective value u based on the high voltage probe output i , the discharge energy W of each discharge can be calculated, the calculation formula is W = 1 / 2*q m *u i The digital signal includes environmental parameters such as temperature, humidity, and air pressure in the sealed discharge chamber.

[0024] S5. After the experiment, the discharge gas products, liquid products and solid residues are collected in sequence.

[0025] First, collect the discharge gas products. Complete the gas pipeline connection as described in step one. Keep the valve of the vent quick-plug valve interface closed, start the small vacuum pump, and extract the air in the negative pressure box to form a negative pressure environment. After completion, stop the small vacuum pump. Open tracheal valve three and tracheal valve four, start vacuum pump two, and extract the air in the air bag, trachea four, trachea five, trachea six, and trachea seven to avoid air interference with the gas products. Then, close tracheal valve four, stop vacuum pump two, and open the vent quick-plug valve interface to allow the gas in the closed discharge chamber to enter the air bag. When the air bag is full of gas, close the vent quick-plug valve interface, disconnect the small vacuum pump from the negative pressure box, open the negative pressure box, and take out the air bag.

[0026] Secondly, collect the discharge liquid product. First, use a dropper to absorb an appropriate amount of chromatographic pure methanol and drop it on the surface of the upper sample and the lower sample to dissolve the liquid product on the surface. Then, use the dropper again to absorb the solution on the surface and drop it into the glass centrifuge tube to complete the collection of the liquid product.

[0027] Finally, the solid residue after discharge is collected. The upper sample and the lower sample are removed from the upper electrode disk and the lower electrode disk, respectively, and cleaned, thereby completing the collection of the solid residue.

[0028] S6. Detect the discharge gas products, liquid products and solid residues, and comprehensively analyze the degradation reaction mechanism of the insulating material under the comprehensive effect of discharge. Specifically, the discharge gas products are detected by gas chromatography-mass spectrometry (GC-MS), and the components are qualitatively analyzed by deconvolution of the GC-MS results, and the relative yield is quantitatively analyzed by peak area. The liquid products are comprehensively detected, and gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) techniques are used to obtain liquid products with different molecular weights and polarity characteristics and their relative contents. The surface of the solid residue is detected using Fourier transform infrared spectroscopy (FTIR) technology and X-ray photoelectron spectroscopy (XPS) technology to analyze the changes in surface functional groups and elements. Based on the above analysis results, combined with the thermal degradation reaction products and mechanisms of the insulating material under the transient high temperature effect of partial discharge in S1, the influence of discharge free radicals in the atmosphere on the degradation reaction mechanism of the insulating material is further analyzed, thereby revealing the degradation reaction mechanism of the insulating material under the comprehensive effect of discharge in a high field strength and complex operating environment.

[0029] The technical effects of the present invention are as follows:

[0030] The present invention provides an experimental device and method for studying the partial discharge aging mechanism of insulating materials, which brings the following beneficial effects:

[0031] 1. Precise control of experimental conditions: The experimental device of the present invention includes a multifunctional closed cavity, a high-voltage circuit, a detection circuit and a monitoring sensor, etc., which can accurately control the discharge environment atmosphere, the discharge gap and the discharge voltage to simulate the partial discharge effect under actual operating conditions. This ability to accurately control experimental conditions makes the results of the partial discharge simulation experiment more credible and repeatable.

[0032] 2. Comprehensive simulation of discharge effect: This experimental device not only covers the instantaneous thermal effect of partial discharge, but also takes into account the comprehensive effects of active products and ultraviolet radiation generated during the discharge process, and fully simulates the complex discharge effects under the actual operating environment. The technical solution of the present invention can provide more comprehensive experimental data for in-depth research on the aging mechanism of insulating materials.

[0033] 3. Comprehensive analysis of aging mechanism: Through the pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) technology, the basic pyrolysis reaction path of insulating materials under the transient thermal effect of discharge is analyzed, and combined with the discharge test results of the experimental device, the chemical functional group changes of solid residues and the composition and relative content of gas and liquid products are systematically analyzed to fully reveal the degradation reaction mechanism of insulating materials under partial discharge. This provides a scientific basis for the modification and optimization of insulating materials.

[0034] 4. Improve experimental efficiency: The experimental device and method of the present invention can monitor the light intensity, discharge amount, discharge energy and other parameters of the discharge process in real time during the experiment, and quickly collect and analyze the discharge products. Compared with the existing technology, the present invention can significantly improve the experimental efficiency and shorten the research cycle.

[0035] 5. Enhanced chemical stability: The inner wall of the closed discharge chamber and the electrode surface are made of materials with high chemical stability, such as titanium-plated electrodes and inorganic glass coverings. These materials will not react with potential discharge products, thus avoiding corrosion or consumption of the experimental device during the discharge process. This ensures the accuracy of product analysis during the experiment and the reliability of the experimental results.

[0036] 6. Strong practicability and applicability: The experimental device of the present invention has a reasonable structural design and is easy to operate, and is suitable for discharge aging research of various high-voltage insulating materials. Its supporting analysis method also has strong applicability and can be widely used in the aging mechanism research of different insulating materials.

[0037] In summary, the experimental device and analysis method provided by the present invention can not only accurately simulate the local discharge effect under high field strength and complex environmental conditions in actual operating conditions, but also comprehensively reveal the aging mechanism of insulating materials, providing important theoretical basis and technical support for improving the service life and reliability of insulating materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the structure of the test device of the present invention in the discharge test state;

[0039] Figure 2 It is a schematic diagram of the structure of the test device of the present invention when the atmosphere is set;

[0040] Figure 3 It is a schematic diagram of the structure of the test device of the present invention in the gas collection state;

[0041] Figure 4 It is a structural schematic diagram of the test device of the present invention when calibrating the discharge capacity state. DETAILED DESCRIPTION

[0042] The specific technical solution of the present invention is described in conjunction with the accompanying drawings.

[0043] First, a discharge comprehensive effect experimental platform with controllable discharge conditions and collectable products was built, that is, an experimental device for studying the partial discharge aging mechanism of insulating materials. Figures 1 to 4 The test device includes: power supply 1, grounding device 1, isolation filter transformer 3, no partial discharge test transformer 4, high voltage probe 5, coaxial cable interface 1, current limiting resistor 7, closed discharge chamber 8, discharge detection branch 24, grounding device 2 28, coaxial cable analog signal line 1 29, coaxial cable analog signal line 2 30, coaxial cable analog signal line 3 31, oscilloscope 32, digital signal line 1 33, digital signal line 2 34, comprehensive data acquisition host computer 35, atmosphere setting system 36, gas collection system 42, calibration pulse generator 57. Among them, the closed discharge chamber 8 includes: organic glass upper cover 9, organic glass lower chamber 10, precision slide 11, upper electrode rod 12, upper electrode disk 13, upper sample 14, lower sample 15, lower electrode disk 16, lower electrode rod 17, optical sensor 18, aviation plug conversion joint 1 19, coaxial cable interface 2 20, ambient air pressure, temperature and humidity multi-in-one sensor 21, aviation plug conversion joint 2 22, charging and discharging gas quick plug valve interface 23. The discharge detection branch 24 includes: coupling capacitor 25, RLC detection impedance 26, coaxial cable interface 2 27. The atmosphere setting system 36 includes: gas cylinder 37, vacuum pump 1 38, three-way quick plug connector 1 39, air pipe 1 40, air pipe 2 41, air pipe 3 42, air pipe valve 1 43, air pipe valve 2 44. The gas collection system 45 includes: a small vacuum pump 46, a negative pressure box 47, an air bag 48, a second vacuum pump 49, a second three-way quick-connect connector 50, a fourth trachea 51, a fifth trachea 52, a sixth trachea 53, a seventh trachea 54, a third trachea valve 55, and a fourth trachea valve 56.

[0044] When in such Figure 1 In the discharge test state shown, the power supply 1 is connected to the grounding device 2 and is also connected to the input of the isolation filter transformer 3. The output of the isolation filter transformer 3 is connected to the input of the no partial discharge test transformer 4. The probe end of the high-voltage probe 5 is mounted on the high-voltage end of the no partial discharge test transformer 4, and the ground end of the high-voltage probe 5 is connected to the ground end of the no partial discharge test transformer 4, and finally connected to the grounding device 28. The signal output of the high-voltage probe 5 is connected to the channel 1 CH1 of the oscilloscope 32 through the coaxial cable analog signal line 29. The high-voltage end of the no partial discharge test transformer 4 is connected to the head end of the current limiting resistor 7, and the ground end of the no partial discharge test transformer 4 is connected to the grounding device 28.

[0045] When in such Figure 1In the discharge experimental state shown, the upper electrode rod 12 of the sealed discharge chamber 8 is connected to the tail end of the current limiting resistor 7, and the lower electrode rod 17 of the sealed discharge chamber 8 is connected to the grounding device 28. In the sealed discharge chamber 8, the precision slide 11 is mechanically connected to the upper electrode rod 12. When the handle of the precision slide 11 is adjusted, the upper electrode rod 12 can move up and down, and the height value of the electrode rod relative to the lower surface of the organic glass upper cover 9 is displayed on the reading window of the precision slide 11. The upper electrode rod 12 is connected to the organic glass upper cover 9 by a cylinder to ensure the sealing. The organic glass upper cover 9 is connected to the organic glass lower chamber 10 by a flange structure, and a rubber sealing ring is provided to ensure the sealing of the sealed discharge chamber 8. The upper electrode rod 12 and the upper electrode disk 13 are connected by threads, and the lower electrode rod 17 and the lower electrode disk 16 are also connected by threads. The edges of the upper electrode disk 13 and the lower electrode disk 16 are both rounded to prevent arcing and avoid direct discharge between metal plates instead of discharge between insulating materials. In order to prevent the strong oxidizing substances generated by the discharge from reacting with the components in the closed discharge chamber 8 and being consumed, thereby causing inaccurate product statistics, the upper electrode rod 12, the upper electrode disk 13, the lower electrode disk 16 and the lower electrode rod 17 are all titanium-plated to ensure chemical stability. In addition, the lower surface of the organic glass upper cover 9 and the inner surface of the organic glass lower chamber 10 are covered with inorganic glass to increase chemical stability. The upper sample 14 is processed, and its inner diameter is the same as the outer diameter of the upper electrode disk 13. The two are fixedly connected in a tight fit manner. The lower sample 15 and the lower electrode disk 16 are also fixedly connected in a tight fit manner to avoid the use of glue and other materials to introduce additional impurities. During the discharge experiment, discharge will occur in the air gap between the upper sample 14 and the lower sample 15, simulating the actual partial discharge phenomenon. By adjusting the handle of the precision slide 11, the air gap spacing between the upper sample 14 and the lower sample 15 can be accurately controlled to simulate the different defect sizes in the high-voltage insulation equipment under the operating conditions. Inside the closed discharge chamber 8, facing the discharge gap, a light sensor 18 is installed to monitor the light intensity of the plasma channel during the discharge process. The light sensor 18 is connected to the oscilloscope 32 channel 2 CH2 through the aviation plug conversion connector 1 19, the coaxial cable interface 2 20 and the coaxial cable analog signal line 2 30 in turn. The closed discharge chamber 8 is also provided with an ambient air pressure, temperature and humidity multi-in-one sensor 21, and the signal is transmitted to the comprehensive data acquisition host computer 35 through the aviation plug conversion connector 2 22 and the digital signal line 1 33. The aviation plug conversion connector 1 19, the aviation plug conversion connector 2 22 and the charging and discharging quick plug valve interface 23 are all embedded and installed in the organic glass cover 9 to ensure the sealing of the closed discharge chamber 8.

[0046] When in such Figure 1In the discharge experimental state shown, the head end of the discharge detection branch 24 is connected to the upper electrode rod 12 of the closed discharge chamber 8, and the tail end of the discharge detection branch 24 is connected to the grounding device 28. Specifically, the head end of the coupling capacitor 25 in the discharge detection branch 24 is connected to the upper electrode rod 12 of the closed discharge chamber 8, the tail end of the coupling capacitor 25 is connected to the head end of the RLC detection impedance 26, and the tail end of the RLC detection impedance 26 is connected to the grounding device 28. The output signal of the RLC detection impedance 26 outputs a voltage signal through the internal mutual inductance coil, and the voltage signal is transmitted to the channel 3 CH3 of the oscilloscope 32 through the coaxial cable interface 27 and the coaxial cable analog signal line 31. The oscilloscope 32 transmits the signal to the comprehensive data acquisition host computer 35 through the digital signal line 2 34.

[0047] When in such Figure 2 In the atmosphere setting state shown, the gas charging and discharging quick-plug valve interface 23 installed on the organic glass upper cover 9 in the closed discharge chamber 8 is connected to the atmosphere setting system 36. Specifically, the interface of the gas cylinder 37 is connected to the first joint of the three-way quick-plug connector 39 through the air pipe 1 40 and the air pipe valve 1 43, the interface of the vacuum pump 1 38 is connected to the second joint of the three-way quick-plug connector 39 through the air pipe 2 41 and the air pipe valve 2 44, and the gas charging and discharging quick-plug valve interface 23 is connected to the third joint of the three-way quick-plug connector 39 through the air pipe 3 42.

[0048] When in such Figure 3 In the gas collection state shown, the quick-discharge valve interface 23 installed on the organic glass upper cover 9 in the closed discharge chamber 8 is connected to the gas collection system 45. Specifically, the small vacuum pump 46 is connected to the first joint of the negative pressure box 47 to extract the air in the negative pressure box 47 to create a negative pressure environment. The air bag 48 placed inside the negative pressure box 47 is connected to the second joint of the negative pressure box 47 through the air pipe 4 51, and the second joint of the negative pressure box 47 is connected to the first joint of the three-way quick-discharge connector 2 50 through the air pipe 5 52 and the air pipe valve 3 55. The vacuum pump 2 49 is connected to the second joint of the three-way quick-discharge connector 2 50 through the air pipe 6 53 and the air pipe valve 4 56. The quick-discharge valve interface 23 is connected to the third joint of the three-way quick-discharge connector 2 50 through the air pipe 7 54.

[0049] When in such Figure 4 In the calibration state shown, based on the wiring method of the discharge experiment state, the power supply 1 is disconnected from the circuit at the same time, and the calibration pulse generator 57 is connected to both ends of the test object. Specifically, the positive output terminal of the calibration pulse generator 57 is connected to the upper electrode rod 12 of the sealed discharge chamber 8, and the negative output terminal of the calibration pulse generator 57 is connected to the lower electrode rod 17 of the sealed discharge chamber 8. The remaining wiring methods remain unchanged from the wiring methods of the discharge experiment state.

[0050] An experimental method for studying the partial discharge aging mechanism of insulating materials is implemented, comprising the following steps:

[0051] S1. Determine the basic pyrolysis reaction mechanism of anhydride-cured bisphenol A epoxy resin under the action of discharge thermal effect. PY-GC-MS transient thermal analysis was carried out on anhydride-cured bisphenol A epoxy resin to analyze its thermal degradation reaction products and mechanism under the transient high temperature effect of partial discharge. Based on this research, further research on the degradation reaction mechanism of the comprehensive discharge effect is planned.

[0052] S2. Process two samples of bisphenol A epoxy resin material cured by anhydride to be analyzed so that they can completely cover the surface and side areas of the electrode disk. Install the upper sample 14 and the lower sample 15 tightly on the upper electrode disk 13 and the lower electrode disk 16 respectively. Fix the upper electrode disk 13 and the lower electrode disk 16 on the upper electrode rod 12 and the lower electrode rod 17 respectively by threaded connection. Then, connect the organic glass upper cover 9 to the organic glass lower chamber 10 by flange and fix them with bolts to ensure the sealing of the closed discharge chamber 8.

[0053] S3. According to the specific research objectives, set the atmosphere in the closed discharge chamber 8. Complete the following steps according to the description of the experimental device: Figure 2 The gas pipeline connection shown. First, close the valve of the gas cylinder 37, open the valve of the trachea valve 1 43, the trachea valve 2 44 and the valve of the quick-plug valve interface 23 for charging and discharging. Start the vacuum pump 1 38 to extract the air in the trachea 1 40, the trachea 2 41, the trachea 3 42 and the closed discharge chamber 8. Observe the air pressure reading of the ambient air pressure, temperature and humidity all-in-one sensor 21 through the comprehensive data acquisition host computer 35. When the air pressure drops to a stable value, close the trachea valve 2 44 and stop the vacuum pump 1 38. Then, open the valve of the gas cylinder 37, fill the required gas into the closed discharge chamber 8 according to the set amount or air pressure ratio, and adjust the required humidity environment according to the experimental purpose. Three different sets of humidity environment tests were designed. ① A dry environment with a relative humidity close to 0% RH was created by placing silica gel desiccant and molecular sieve in the closed discharge chamber 8. ② An inorganic glass culture dish containing different types of saturated ion solutions was placed to create a semi-humid environment with different relative humidity. ③ An inorganic glass culture dish containing deionized water was placed to create a humid environment with a relative humidity close to 100%. Finally, the valve of the quick-plug valve interface 23 of the gas charging and discharging valve was closed, the valve of the gas cylinder 37 was closed, and the connection between the gas pipe 3 42 and the quick-plug valve interface 23 of the gas charging and discharging valve was disconnected to complete the atmosphere environment setting in the closed discharge chamber 8.

[0054] S4, calibrate the proportional relationship between the output voltage of the RLC detection impedance 26 and the discharge amount. Complete the following steps according to the description of the test device: Figure 4The connection of the high voltage circuit and the signal detection circuit is shown. Start the calibration pulse generator 57, output the pulse signal, and inject a certain amount of charge into the circuit where the sample is located. Set the output calibration charge amount to q c (pC), record the pulse voltage amplitude u of oscilloscope 32 channel 3 CH3 c (mV), for example, the output calibration charge is set to 50pC, 100pC, and 500pC respectively, and the pulse voltage amplitudes of CH3 of oscilloscope 32 channel 3 are observed to be 50mV, 100mV, and 500mV respectively, so the calibration coefficient K = u c / q c ≈1. When the discharge experiment is carried out formally, the pulse voltage amplitude u of channel 3 CH3 of oscilloscope 32 is detected and recorded. m (mV), divided by the calibration coefficient K, the discharge amount q of each discharge can be obtained m (pC).

[0055] S5. Apply high voltage to the insulating material in the closed discharge chamber 8 to formally carry out the discharge experiment. Adjust the console knob of the non-partial discharge test transformer 4, and observe the voltage average value of channel 1 (CH1) of the oscilloscope 32 until the required set value is reached. Start the comprehensive data acquisition host computer 35, and regularly record the analog signals output by the high-voltage probe 5, the optical sensor 18, and the RLC detection impedance 26 read by the oscilloscope 32, as well as the digital signals directly output by the ambient air pressure, temperature and humidity all-in-one sensor 21. The analog signal includes the transformer output voltage output by the high-voltage probe 5, the discharge light pulse intensity output by the optical sensor 18, and the discharge pulse voltage signal output by the RLC detection impedance 26. Based on the discharge pulse voltage signal waveform output by the RLC detection impedance 26, the discharge amount q of each discharge can be calculated. m (pC), calculated as q m =u c On this basis, based on the transformer output voltage effective value u output by the high voltage probe 5 i , the discharge energy W of each discharge can be calculated, the calculation formula is W = 1 / 2*q m *u i The digital signal includes environmental parameters such as temperature, humidity, and air pressure in the sealed discharge chamber 8 .

[0056] S5. After the experiment, the discharge gas products, liquid products and solid residues are collected in sequence.

[0057] First, collect the discharge gas products. Follow the steps in step 1 to complete the following steps: Figure 3The gas pipeline connection shown. Keep the valve of the deflation quick-insert valve interface 23 in the closed state, start the small vacuum pump 46, and extract the air in the negative pressure box 47 to form a negative pressure environment. After completion, stop the small vacuum pump 46. Open the trachea valve three 55 and the trachea valve four 56, start the vacuum pump two 49, and extract the air in the air bag 48, the trachea four 51, the trachea five 52, the trachea six 53, and the trachea seven 54 to avoid the interference of air on the gas product. Then, close the trachea valve four 56, stop the vacuum pump two 49, open the deflation quick-insert valve interface 23, and allow the gas in the closed discharge chamber 8 to enter the air bag 48. When the air bag 48 is full of gas, close the deflation quick-insert valve interface 23, disconnect the small vacuum pump 46 from the negative pressure box 47, open the negative pressure box 47, and take out the air bag 48.

[0058] Secondly, collect the discharge liquid product. First, use a dropper to absorb 1 mL of chromatographic pure methanol and drop it on the surface of upper sample 4 and lower sample 15 to dissolve the liquid product on the surface. Then, use a dropper again to absorb the solution on the surface and drop it into a glass centrifuge tube to complete the collection of the liquid product.

[0059] Finally, the solid residue after discharge is collected. The upper sample 14 and the lower sample 15 are removed from the upper electrode disk 13 and the lower electrode disk 16 respectively, and cleaned, thereby completing the collection of the solid residue.

[0060] S6. Detect the discharge gas products, liquid products and solid residues, and comprehensively analyze the degradation reaction mechanism of the insulating material under the comprehensive effect of discharge. Specifically, the discharge gas products are detected by gas chromatography-mass spectrometry (GC-MS), and the components are qualitatively analyzed by deconvolution of the GC-MS results, and the relative yield is quantitatively analyzed by peak area. The liquid products are comprehensively detected, and gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) techniques are used to obtain liquid products with different molecular weights and polarity characteristics and their relative contents. The surface of the solid residue is detected using Fourier transform infrared spectroscopy (FTIR) technology and X-ray photoelectron spectroscopy (XPS) technology to analyze the changes in surface functional groups and elements. Based on the above analysis results, combined with the thermal degradation reaction products and mechanisms of the insulating material under the transient high temperature effect of partial discharge in S1, the influence of discharge free radicals in the atmosphere on the degradation reaction mechanism of the insulating material is further analyzed, thereby revealing the degradation reaction mechanism of the insulating material under the comprehensive effect of discharge in a high field strength and complex operating environment.

Claims

1. An experimental device for studying the partial discharge aging mechanism of insulating materials, characterized in that: It comprises a power source (1), a sealed discharge chamber (8) and a discharge quantity detection branch (24); The power supply (1) is connected to a grounding device 1 (2) and is also connected to the input of an isolation filter transformer (3); the output of the isolation filter transformer (3) is connected to the input of a non-partial discharge test transformer (4); the probe end of the high-voltage probe (5) is mounted on the high-voltage end of the non-partial discharge test transformer (4), the ground end of the high-voltage probe (5) is connected to the ground end of the non-partial discharge test transformer (4), and is finally connected to a grounding device 2 (28); the signal output of the high-voltage probe (5) is connected to a channel 1 CH1 of an oscilloscope (32) via a coaxial cable analog signal line 1 (29); the high-voltage end of the non-partial discharge test transformer (4) is connected to the head end of a current limiting resistor (7), and the ground end of the non-partial discharge test transformer (4) is connected to a grounding device 2 (28); The sealed discharge chamber (8) comprises an organic glass upper cover (9), an organic glass lower chamber (10), an upper electrode rod (12) and a lower electrode rod (17); the organic glass upper cover (9) and the organic glass lower chamber (10) are sealed and connected via a flange structure; the upper electrode rod (12) is connected to the tail end of the current limiting resistor (7), and the lower electrode rod (17) is connected to a second grounding device (28); in the sealed discharge chamber (8), a precision slide (11) is mechanically connected to the upper electrode rod (12), and when the handle of the precision slide (11) is adjusted, the upper electrode rod (12) can move up and down. The height value of the upper electrode rod (12) relative to the lower surface of the organic glass upper cover (9) is displayed on the reading window of the precision slide (11); the upper electrode rod (12) and the organic glass upper cover (9) are connected by a cylinder seal; the upper electrode rod (12) and the upper electrode disk (13) are fixedly connected, and the lower electrode rod (17) and the lower electrode disk (16) are fixedly connected; the upper electrode disk (13) and the lower electrode disk (16) are arranged opposite to each other, the upper sample (14) and the upper electrode disk (13) are fixedly connected in a tight fit manner, and the lower sample (15) and the lower electrode disk (16) are also fixedly connected in a tight fit manner. The upper sample (14) and the lower sample (15) are fixedly connected in a manner such that during the discharge experiment, discharge will occur in the air gap between the upper sample (14) and the lower sample (15), simulating the actual partial discharge phenomenon. By adjusting the handle of the precision slide (11), the air gap distance between the upper sample (14) and the lower sample (15) is controlled to simulate the different sizes of defects that occur in the high-voltage insulation equipment under the operating conditions; inside the closed discharge chamber (8), facing the position of the discharge gap, an optical sensor (18) is installed to monitor the light intensity of the plasma channel during the discharge process; the optical sensor (18) is sequentially connected to the air gap through the aviation plug conversion connector (11) 9), the coaxial cable interface 2 (20) and the coaxial cable analog signal line 2 (30) are connected to the oscilloscope (32) channel 2 CH2; the closed discharge chamber (8) is also provided with an ambient air pressure, temperature and humidity multi-in-one sensor (21), and the signal is transmitted to the comprehensive data acquisition host computer (35) through the aviation plug conversion connector 2 (22) and the digital signal line 1 (33); the aviation plug conversion connector 1 (19), the aviation plug conversion connector 2 (22) and the charging and discharging quick plug valve interface (23) are all embedded and installed in the organic glass upper cover (9) to ensure the sealing of the closed discharge chamber (8); The head end of the discharge amount detection branch (24) is connected to the upper electrode rod (12) of the sealed discharge chamber (8), and the tail end of the discharge amount detection branch (24) is connected to the second grounding device (28); It also includes an atmosphere setting system (36). When in the atmosphere setting state, the gas charging and discharging quick-plug valve interface (23) installed on the organic glass upper cover (9) in the closed discharge chamber (8) is connected to the atmosphere setting system (36); It also includes a gas collection system (45). When in a gas collection state, a gas charging and discharging quick-plug valve interface (23) installed on the organic glass upper cover (9) in the closed discharge chamber (8) is connected to the gas collection system (45); It also includes a calibration pulse generator (57). Based on the wiring method of the discharge test state, the power supply (1) is disconnected from the circuit at the same time, and the calibration pulse generator (57) is connected to the two ends of the test object.

2. The experimental device for studying the partial discharge aging mechanism of insulating materials according to claim 1 is characterized in that: The edges of the upper electrode disk (13) and the lower electrode disk (16) are both designed with rounded corners; the upper electrode rod (12), the upper electrode disk (13), the lower electrode disk (16) and the lower electrode rod (17) are all titanium-plated; and the lower surface of the organic glass upper cover (9) and the inner surface of the organic glass lower cavity (10) are both covered with inorganic glass.

3. The experimental device for studying the partial discharge aging mechanism of insulating materials according to claim 1 is characterized in that: The discharge amount detection branch (24) comprises: a coupling capacitor (25) and an RLC detection impedance (26); the head end of the coupling capacitor (25) is connected to the upper electrode rod (12) of the sealed discharge chamber (8); the tail end of the coupling capacitor (25) is connected to the head end of the RLC detection impedance (26); the tail end of the RLC detection impedance (26) is connected to a second grounding device (28); the output signal of the RLC detection impedance (26) outputs a voltage signal through an internal mutual inductance coil; the voltage signal is transmitted to a third channel CH3 of an oscilloscope (32) through a second coaxial cable interface (27) and a third coaxial cable analog signal line (31); the oscilloscope (32) transmits the signal to a comprehensive data acquisition host computer (35) through a second digital signal line (34).

4. The experimental device for studying the partial discharge aging mechanism of insulating materials according to claim 1 is characterized in that: The atmosphere setting system (36) comprises: a gas cylinder (37), the interface of the gas cylinder (37) is connected to the first joint of the three-way quick-connection connector (39) through an air pipe (40) and an air pipe valve (43), the interface of the vacuum pump (38) is connected to the second joint of the three-way quick-connection connector (39) through an air pipe (41) and an air pipe valve (44), and the interface of the charging and discharging quick-connection valve (23) is connected to the third joint of the three-way quick-connection connector (39) through an air pipe (42).

5. The experimental device for studying the partial discharge aging mechanism of insulating materials according to claim 1 is characterized in that: The gas collection system (45) comprises: a small vacuum pump (46), a negative pressure box (47), and an air bag (48); the small vacuum pump (46) is connected to the first joint of the negative pressure box (47) to extract the air in the negative pressure box (47) to create a negative pressure environment; the air bag (48) placed inside the negative pressure box (47) is connected to the second joint of the negative pressure box (47) through the air pipe four (51), and the second joint of the negative pressure box (47) is connected to the first joint of the three-way quick plug connector two (50) through the air pipe five (52) and the air pipe valve three (55); the vacuum pump two (49) is connected to the second joint of the three-way quick plug connector two (50) through the air pipe six (53) and the air pipe valve four (56); the charging and discharging quick plug valve interface (23) is connected to the third joint of the three-way quick plug connector two (50) through the air pipe seven (54).

6. The experimental device for studying the partial discharge aging mechanism of insulating materials according to claim 1 is characterized in that: When in the calibration discharge state, the positive output terminal of the calibration pulse generator (57) is connected to the upper electrode rod (12) of the sealed discharge chamber (8), and the negative output terminal of the calibration pulse generator (57) is connected to the lower electrode rod (17) of the sealed discharge chamber (8).

7. An experimental method for studying the partial discharge aging mechanism of insulating materials, characterized in that: An experimental device for studying the partial discharge aging mechanism of insulating materials according to any one of claims 1 to 6; The method comprises the following steps: S1. Determine the basic pyrolysis reaction mechanism of the insulating material under the action of discharge thermal effect; conduct PY-GC-MS transient thermal analysis on the high-voltage insulating material to be analyzed to analyze its thermal degradation reaction products and mechanism under the transient high temperature effect of partial discharge; on the basis of this research, further study on the degradation reaction mechanism of the comprehensive discharge effect is prepared; S2. Process two insulating material samples to be analyzed so that they can completely cover the surface and side areas of the electrode disk; tightly install the upper sample (14) and the lower sample (15) on the upper electrode disk (13) and the lower electrode disk (16) respectively; fix the upper electrode disk (13) and the lower electrode disk (16) on the upper electrode rod (12) and the lower electrode rod (17) respectively by threaded connection; then, connect the organic glass upper cover (9) and the organic glass lower chamber (10) by flange, and fix them with bolts to ensure the sealing of the closed discharge chamber (8); S3. According to the research objectives, the atmosphere environment in the sealed discharge chamber (8) is set; the gas pipeline connection is completed; first, the air in the sealed discharge chamber (8) is extracted through the atmosphere setting system (36), and then the required gas is filled into the sealed discharge chamber (8) according to the set amount or gas pressure ratio, and the required humidity environment is adjusted according to the experimental purpose; S4, calibrate the proportional relationship between the output voltage of the discharge detection branch (24) and the discharge amount; complete the connection between the high-voltage circuit and the signal detection circuit; start the calibration pulse generator (57), output a pulse signal, and inject a certain amount of charge into the circuit where the sample is located; set the output calibration charge amount to q c (pC), record the pulse voltage amplitude u of the oscilloscope (32) c (mV), and obtain the calibration coefficient K = u c / q c When the discharge experiment is carried out formally, the pulse voltage amplitude u is detected and recorded by the oscilloscope (32). m (mV), divided by the calibration coefficient K, that is, the discharge amount q of each discharge is obtained m (pC); S5, applying high voltage to the insulating material in the sealed discharge chamber (8) to formally carry out the discharge experiment; adjusting the control knob of the non-partial discharge test transformer (4) to observe the voltage average value of the oscilloscope (32) until the required set value is reached; starting the comprehensive data acquisition host computer (35) to regularly record the analog signals output by the high-voltage probe (5), the optical sensor (18), and the discharge amount detection branch (24) read by the oscilloscope (32), as well as the digital signals directly output by the ambient air pressure, temperature and humidity multi-in-one sensor (21); the analog signals include the transformer output voltage output by the high-voltage probe (5), the discharge light pulse intensity output by the optical sensor (18) and the discharge pulse voltage signal output by the discharge amount detection branch (24); based on the discharge pulse voltage signal waveform output by the discharge amount detection branch (24), the discharge amount q of each discharge is calculated. m (pC), calculated as q m =u c / K; On this basis, the transformer output voltage effective value u based on the output of the high voltage probe (5) i , calculate the discharge energy W of each discharge, the calculation formula is W = 1 / 2*q m *u i ; The digital signal includes the temperature, humidity and air pressure environmental parameters in the sealed discharge chamber (8); S5. After the experiment, the discharge gas product, liquid product and solid residue are collected in sequence; S6. Detect discharge gas products, liquid products and solid residues, and comprehensively analyze the degradation reaction mechanism of insulating materials under the comprehensive effect of discharge.

8. An experimental method for studying the partial discharge aging mechanism of insulating materials according to claim 7, characterized in that: The specific method of S6 is: The discharge gas products were detected by gas chromatography-mass spectrometry (GC-MS), and their components were qualitatively analyzed by deconvolution of the GC-MS results, and the relative yield was quantitatively analyzed by peak area. The liquid products were comprehensively detected, and gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) were used to obtain liquid products with different molecular weights and polarity characteristics and their relative contents. The surface of the solid residues was detected by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) to analyze the changes in surface functional groups and elements. The above analysis results were combined with the thermal degradation reaction products and mechanisms of the insulating materials under the transient high temperature effect of local discharge, and the influence of discharge free radicals in the atmosphere on the degradation reaction mechanism of the insulating materials was further analyzed, thereby revealing the degradation reaction mechanism of the insulating materials under the comprehensive effect of discharge in a high field strength and complex operating environment.

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