Electro-acoustic pulse measurement system and method for gas-solid interface charge of solid insulating materials

Abstract

The application discloses a kind of electroacoustic pulse measurement system and method of solid insulation material gas-solid interface charge, it is related to high voltage and insulation technical field.The system includes external circuit unit, electrode unit and signal acquisition unit;Electrode unit includes working electrode, epoxy board, shielding shell, epoxy pad, flat plate sample and lower electrode;Working electrode is discharge electrode or test electrode;External circuit unit is detachably connected with working electrode, and working electrode is detachably embedded in epoxy board, and epoxy board and shielding shell are connected and fixed, and working electrode, epoxy board and shielding shell are concentric, and the lowermost end of working electrode is at the same horizontal plane with the lowermost end of shielding shell;Discharge electrode is an electrode with uniformly distributed needle tips, and test electrode is a flat plate electrode;Epoxy pad is clamped between shielding shell and flat plate sample;Flat plate sample is attached to lower electrode, lower electrode is grounded, and is connected with signal acquisition unit.The system can accurately measure the gas-solid interface charge of solid insulation material.

Description

Technical Field

[0001] This invention relates to the field of high voltage and insulation technology, and in particular to an electroacoustic pulse measurement system and method for the gas-solid interface charge of solid insulating materials. Background Technology

[0002] High-voltage direct current (HVDC) transmission is a crucial means for major power-producing countries worldwide to solve long-distance, high-capacity power transmission and grid interconnection issues. It promotes the clean and efficient development and utilization of various energy sources and facilitates the optimal allocation of energy resources over a wider area. Compared to traditional overhead lines, gas-insulated metal-enclosed transmission lines (GILs) offer advantages such as large transmission capacity, small footprint, less susceptibility to external environmental influences, and high operational stability, making them an important supplementary method for future integration of new energy sources like offshore wind power and energy transmission in urbanization. With the advocacy and implementation of green, low-carbon, and sustainable development initiatives, the development of high-voltage electrical equipment faces new opportunities and challenges. Environmentally friendly gas-insulated substations (GIS) / GILs and DC interruptors are emerging as new development directions.

[0003] Under DC voltage, due to the long-term effect of a unipolar electric field, charged particles in sulfur hexafluoride (SF6) gas and charge carriers in the insulating material gradually transfer to the gas-solid interface, leading to significant interfacial charge accumulation on the surface of the insulator in the gas-solid interface. This causes distortion of the electric field at the gas-solid interface, easily inducing surface flashover of the insulator, and seriously affecting the safe and stable operation of the DC system. However, insulators in DC GILs also face the combined effects of multiple operating conditions such as temperature gradients, metal particles, and polarity voltage reversal, making their surface charge accumulation behavior and electric field distribution characteristics extremely complex.

[0004] Therefore, how to accurately measure the gas-solid interface charge of solid insulating materials has become a key technical challenge in this field. Summary of the Invention

[0005] Therefore, it is necessary to provide an electroacoustic pulse measurement system and method for the gas-solid interface charge of solid insulating materials to address the above-mentioned technical problems. This system can achieve accurate measurement of the gas-solid interface charge of solid insulating materials.

[0006] The present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides an electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials. The system includes: an external circuit unit, an electrode unit, and a signal acquisition unit; the electrode unit includes a working electrode, an epoxy plate, a shielding shell, an epoxy pad, a flat sample, and a lower electrode.

[0008] The external circuit unit is detachably connected to the working electrode, which is detachably embedded in the epoxy board. The epoxy board and the shielding shell are connected and fixed. The working electrode, epoxy board, and shielding shell are concentric, and the lowest point of the working electrode and the lowest point of the shielding shell are on the same horizontal plane. The epoxy pad is sandwiched between the shielding shell and the flat plate sample. The thickness of the epoxy pad is the height of the air gap between the working electrode and the flat plate sample. The flat plate sample is attached to the lower electrode, which is grounded and connected to the signal acquisition unit.

[0009] The external circuit unit is used to simultaneously apply pulse excitation and DC excitation to the discharge electrode or the test electrode, respectively.

[0010] The working electrode is used to transmit a voltage signal after being excited and to apply the voltage signal to the plate sample;

[0011] The signal acquisition unit is used to acquire the acoustic signal generated when a voltage is applied to the flat plate sample, and to obtain the charge distribution at the gas-solid interface of the insulating material based on the acoustic signal.

[0012] The working electrode is either a discharge electrode or a test electrode; the discharge electrode is an electrode with uniformly distributed needle tips, and the test electrode is a flat plate electrode. The discharge electrode and the test electrode are identical in all other dimensions and materials.

[0013] When measuring the charge distribution at the gas-solid interface of insulating materials, the discharge electrode is used as the working electrode. After the signal acquisition unit acquires the acoustic signal generated by the discharge electrode, it replaces the discharge electrode with the test electrode. The signal acquisition unit then acquires the acoustic signal generated by the test electrode and obtains the charge distribution at the gas-solid interface of the insulating material based on the two acquired acoustic signals.

[0014] In one embodiment, the external circuit unit includes a pulse source, a capacitor, a coupling resistor, a protection resistor, and a DC source; one end of the pulse source is connected to one end of the coupling resistor and one end of the capacitor, the other end of the pulse source is grounded, the other end of the coupling resistor is grounded, one end of the DC source is connected to one end of the protection resistor, the other end of the DC source is grounded, and the other ends of the capacitor and the protection resistor are both connected to a discharge electrode or a test electrode.

[0015] In one embodiment, the signal acquisition unit includes a piezoelectric sensor, a signal amplifier, an oscilloscope, and a computer; the piezoelectric sensor is connected to the oscilloscope via the signal amplifier, and the oscilloscope is connected to the computer.

[0016] The piezoelectric sensor converts the acoustic signal generated when a voltage is applied to the flat plate sample into a voltage signal. The voltage signal is then amplified by a signal amplifier and displayed on an oscilloscope. The oscilloscope then transmits the display data to a computer. The computer collects and processes the received data to obtain the charge distribution at the gas-solid interface of the insulating material.

[0017] In one embodiment, the electrode unit is placed in a sealed environment.

[0018] In one embodiment, the diameters of both the discharge electrode and the test electrode are smaller than the inner diameter of the epoxy mat.

[0019] In one embodiment, the flat plate sample is an epoxy resin or other polymer film.

[0020] In one embodiment, the pulse source is a nanosecond pulse source; the coupling resistor is 50Ω, and the protection resistor is greater than 5MΩ.

[0021] In a second aspect, the present invention provides an electroacoustic pulse measurement method for the gas-solid interface charge of a solid insulating material, the method being applied to the system described in any embodiment of the first aspect above, the method comprising:

[0022] The external circuit unit simultaneously applies pulse excitation and DC excitation to the discharge electrode so that the voltage generated after the discharge electrode is excited is applied to the plate sample.

[0023] The first space charge waveform signal is determined by acquiring the acoustic signal generated after a voltage is applied to the flat plate sample using the signal acquisition unit.

[0024] The discharge electrode is replaced with the test electrode, and the same excitation as that used during the discharge electrode test is applied to the test electrode through the external circuit unit;

[0025] The second space charge waveform distribution is determined based on the acoustic signal generated by the flat plate sample under the corresponding test electrode acquired by the signal acquisition unit.

[0026] The charge distribution at the gas-solid interface of the insulating material is obtained by calibrating the second space charge waveform signal using the first space charge waveform signal.

[0027] In one embodiment, the charge distribution at the gas-solid interface of the insulating material is obtained by calibrating a second space charge waveform signal using a first space charge waveform signal, including:

[0028] Based on the initial electric field applied to the plate sample when acquiring the first space charge waveform signal, the amplitude of the first space charge waveform signal, and the amplitude of the second space charge waveform signal, the initial electric field applied to the plate sample when acquiring the second space charge waveform signal is determined.

[0029] The amplitude of the second space charge waveform signal during signal processing is calibrated based on the initial electric field applied to the flat plate sample when the second space charge waveform signal is acquired.

[0030] The charge distribution at the gas-solid interface of the insulating material is obtained based on the amplitude of the calibrated second space charge waveform signal.

[0031] Optionally, the method for obtaining the initial electric field applied to the flat plate sample when acquiring the first space charge waveform signal includes:

[0032] The ratio of the voltage applied to the discharge electrode to the thickness of the plate sample is determined as the initial electric field applied to the plate sample when acquiring the first space charge waveform signal.

[0033] Thirdly, the present invention provides an electroacoustic pulse measurement device for the gas-solid interface charge of a solid insulating material, which is applied to the system described in any embodiment of the first aspect above, and the device includes:

[0034] The first excitation module is used to simultaneously apply pulse excitation and DC excitation to the discharge electrode through the external circuit unit, so that the voltage generated after the discharge electrode is excited is applied to the plate sample.

[0035] The first acquisition module is used to acquire the acoustic signal generated after the plate sample is subjected to voltage by the signal acquisition unit, and to determine the first space charge waveform signal.

[0036] The second excitation module is used to replace the discharge electrode with the test electrode and apply the same excitation to the test electrode as when testing the discharge electrode through the external circuit unit;

[0037] The second acquisition module is used to determine the second space charge waveform distribution based on the acoustic signal generated by the flat plate sample under the corresponding test electrode acquired by the signal acquisition unit.

[0038] The calibration module is used to calibrate the second space charge waveform signal using the first space charge waveform signal to obtain the charge distribution at the gas-solid interface of the insulating material.

[0039] The present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for measuring the electroacoustic pulse charge at the gas-solid interface of a solid insulating material.

[0040] The present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-mentioned method for measuring the electroacoustic pulse charge at the gas-solid interface of solid insulating materials.

[0041] The above-mentioned at least one technical solution adopted in this invention can achieve the following beneficial effects:

[0042] The working electrode, epoxy plate, and shielding shell are concentric, with the lowest point of the working electrode and the lowest point of the shielding shell at the same horizontal plane. This design ensures the symmetry of the electric field distribution. When an external circuit unit applies excitation, the symmetrical electric field structure makes the injection and distribution of charge at the gas-solid interface more uniform and predictable. Furthermore, the epoxy plate fixes and insulates the working electrode, while the shielding shell and lower electrode provide excellent electromagnetic shielding, effectively reducing the impact of external electromagnetic interference on the measurement system. The epoxy padding layer creates an air gap between the working electrode and the flat sample and allows for adjustment of the air gap height, enabling precise control of the gap size. The working electrode can be either a discharge electrode or a test electrode. The discharge electrode uses an electrode with uniformly distributed needle tips, while the test electrode is a flat electrode, with all other dimensions and materials identical. This design facilitates comparison and calibration. During measurement, voltage can be injected using the discharge electrode first, followed by switching to the test electrode for measurement. Due to the identical size and material, the influence of factors other than differences in electrode shape on the measurement can be mutually canceled out. For example, using the same material ensures consistent electrode conductivity, preventing variations in charge injection amount and rate due to differences in the material itself, thus improving measurement accuracy. Therefore, this system can accurately measure the charge at the gas-solid interface of solid insulating materials. Attached Figure Description

[0043] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0044] Figure 1 A schematic diagram of the structure of an electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials provided by the present invention;

[0045] Figure 2 A schematic diagram of the structure of another electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials provided by the present invention;

[0046] Figure 3 A schematic diagram of the structure of another electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials provided by the present invention;

[0047] Figure 4 A schematic diagram of the structure of another electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials provided by the present invention;

[0048] Figure 5 A schematic flowchart of an electroacoustic pulse measurement method for the gas-solid interface charge of a solid insulating material provided by the present invention;

[0049] Figure 6A schematic diagram of an electroacoustic pulse measuring device for the gas-solid interface charge of solid insulating materials provided by the present invention.

[0050] Figure 7 This is a schematic diagram of a computer device for measuring the electroacoustic pulse charge at the gas-solid interface of a solid insulating material, as provided by the present invention.

[0051] Explanation of reference numerals in the attached figures:

[0052] 101. External circuit unit; 102. Electrode unit; 103. Signal acquisition unit; 104. Discharge electrode; 105. Epoxy board; 106. Shielding shell; 107. Epoxy pad; 108. Flat plate sample; 109. Lower electrode;

[0053] 301. Test electrode;

[0054] 301. Pulse source; 302. Capacitor; 303. Coupling resistor; 304. Protective resistor; 305. DC source; 306. Piezoelectric sensor; 307. Signal amplifier; 308. Oscilloscope; 309. Computer. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0056] Studying the accumulation and dissipation characteristics of gas-solid interfaces in insulating materials and understanding the mechanism of surface flashover at gas-solid interfaces is of great significance for the reliable operation of gas-solid insulation systems (GILs).

[0057] Currently, the measurement of charge distribution at the gas-solid interface is generally divided into qualitative and quantitative measurements. Qualitative measurements are typically used to corroborate quantitative measurement results and do not meet research needs. Quantitative measurements are further divided into invasive and in-situ methods. Commonly used methods include dust mapping (qualitative), the Pockels effect method (invasive), and the electrostatic probe method (invasive). The dust mapping method cannot quantitatively characterize the surface charge density, and the sprayed dust can affect the original charge distribution. The Pockels effect transmission method can achieve online real-time measurement, but it can only measure transparent thin film materials. The Pockels effect reflection method can be used for opaque insulating materials, but it has limitations on material thickness and electrode materials, and is mainly used for dielectric barrier discharge, thus limiting its application. The electrostatic probe method's measurement probe can affect the charge distribution at the gas-solid interface and cannot measure in real time. In-situ measurement methods measure the electric field distribution at the gas-solid interface, but cannot directly obtain the charge distribution at the gas-solid interface, and the testing systems are expensive.

[0058] Pulsed Electro-Acoustic (PEA) is a non-destructive measurement method for the space charge of solid insulating materials. Its testing principle involves applying a pulse excitation to the solid insulating material, causing the internal charges to vibrate and generate sound waves. These sound waves propagate in two opposite directions within the medium, and their amplitude is linearly related to the charge density at the location where the sound waves are generated. The acoustic signal transmitted to a piezoelectric sensor near the electrode is converted into an electrical signal, which is then analyzed (waveform recovery) to obtain the space charge distribution inside the sample. The PEA method has advantages such as strong anti-interference capability, low cost, high sensitivity, and continued usability even in the presence of corona discharge. Improving the electrode system of the PEA method to achieve accurate measurement of the gas-solid interface charge of insulating materials holds great promise for future applications.

[0059] Based on this, the present invention provides an electroacoustic pulse measurement system for the charge distribution at the gas-solid interface of solid insulating materials based on PEA, which can accurately measure the real-time charge distribution at the gas-solid interface of insulating materials under different test conditions.

[0060] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0061] This invention provides an electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials, such as... Figure 1 and Figure 2 As shown, the system includes: an external circuit unit 101, an electrode unit 102, and a signal acquisition unit 103; the electrode unit 102 includes a working electrode, an epoxy plate 105, a shielding shell 106, an epoxy pad 107, a flat sample 108, and a lower electrode 109.

[0062] The external circuit unit 101 is detachably connected to the working electrode, which is detachably embedded in the epoxy plate 105. The epoxy plate 105 and the shielding shell 106 are connected and fixed. The working electrode, epoxy plate 105 and shielding shell 106 are concentric, and the lowest end of the working electrode and the lowest end of the shielding shell 106 are on the same horizontal plane. The epoxy pad 107 is sandwiched between the shielding shell 106 and the flat plate sample 108. The thickness of the epoxy pad 107 is the height of the air gap between the working electrode and the flat plate sample 108. The flat plate sample 108 is attached to the lower electrode 109, which is grounded and connected to the signal acquisition unit.

[0063] The thickness of the epoxy pad 107 is adjustable, and the height of the air gap between the working electrode and the flat sample 108 can be controlled by changing the thickness of the epoxy pad 107. The shielding shell 107 and the lower electrode 109 can provide good electromagnetic shielding, preventing the signal from being interfered with by the environment during testing.

[0064] The external circuit unit 101 is used to detachably connect to the working electrode and simultaneously apply pulse excitation and DC excitation; the working electrode is used to apply the voltage signal generated after the excitation is applied to the flat plate sample 108; the signal acquisition unit 103 is used to acquire the acoustic signal generated after the voltage is applied to the flat plate sample 108, and obtain the charge distribution of the gas-solid interface of the insulating material based on the acoustic signal.

[0065] The epoxy plate 105 is used to fix the working electrode and provide insulation, the shielding shell 106 is used to fix the epoxy plate 105 and provide electromagnetic shielding, the epoxy pad 107 is used to create an air gap and adjust the air gap height, and the lower electrode 109 is used to make close contact with the lower surface of the flat plate sample 108 and transmit acoustic signals.

[0066] The working electrode is either the discharge electrode 104 or the test electrode 201. The discharge electrode 104 and the test electrode 201 can be freely disassembled and replaced. It should be noted that... Figure 1 This is a schematic diagram showing that the working electrode is the discharge electrode 104. Figure 2 This is a schematic diagram of the working electrode and the test electrode 201. The discharge electrode 104 is an electrode with uniformly distributed needle tips, and the test electrode 201 is a flat plate electrode. The discharge electrode 104 and the test electrode 201 are identical in other dimensions and materials.

[0067] When measuring the charge distribution at the gas-solid interface of insulating materials, the discharge electrode is used as the working electrode (see [reference]). Figure 1 After acquiring the acoustic signal generated by the discharge electrode, the signal acquisition unit replaces the discharge electrode with a test electrode (see [link]). Figure 2 The signal acquisition unit acquires the acoustic signal generated by the test electrode and obtains the charge distribution at the gas-solid interface of the insulating material based on the two acquired acoustic signals.

[0068] In one embodiment, the electrode unit 102 is placed in a closed environment. For example, the electrode unit 102 may be placed in air or other closed environments for testing, and the air pressure and gas type may be adjusted according to experimental requirements.

[0069] In one embodiment, the diameters of the discharge electrode 104 and the test electrode 201 are smaller than the inner diameter of the epoxy pad 107. The diameters of the discharge electrode 104 and the test electrode 201 should be significantly smaller than the inner diameter of the epoxy pad 107 to prevent voltage from being applied to the epoxy pad 107 and affecting the test results; for example, the inner diameter of the epoxy pad 107 should be larger than a predetermined difference between the diameters of the discharge electrode 104 and the test electrode 201.

[0070] In one embodiment, the flat plate sample 108 is an epoxy resin or other polymer film.

[0071] like Figure 3 As shown, the external circuit unit includes a pulse source 301, a capacitor 302, a coupling resistor 303, a protection resistor 304, and a DC source 305. One end of the pulse source 301 is connected to one end of the coupling resistor 303 and one end of the capacitor 302, respectively. The other end of the pulse source 301 is grounded, and the other end of the coupling resistor 303 is grounded. One end of the DC source 305 is connected to one end of the protection resistor 304, and the other end of the DC source 305 is grounded. The other ends of the capacitor 302 and the other ends of the protection resistor 304 are both connected to the discharge electrode 104 or the test electrode 201.

[0072] The pulse source 301 is connected to the coupling resistor 303 and the capacitor 302, with the other end of the coupling resistor 303 grounded. The DC source 305 is connected to the protection resistor 304. The other ends of the capacitor 302 and the protection resistor 304 are both connected to the discharge electrode 104 or the test electrode 201, forming a closed loop. This allows the pulse excitation and the DC excitation to be applied simultaneously to the discharge electrode 104 or the test electrode 201. The pulse excitation causes the charge inside the flat plate sample 108 to vibrate, generating an acoustic signal that propagates in opposite directions within the flat plate sample 108.

[0073] The signal acquisition unit 103 includes a piezoelectric sensor 306, a signal amplifier 307, an oscilloscope 308, and a computer 309; the piezoelectric sensor 306 is connected to the oscilloscope 308 via the signal amplifier 307, and the oscilloscope 308 is connected to the computer 309.

[0074] The piezoelectric sensor 306 converts the acoustic signal generated when the plate sample 108 is subjected to voltage into a voltage signal. The voltage signal is amplified by the signal amplifier 307 and displayed on the oscilloscope 308. The oscilloscope 308 then transmits the display data to the computer 309. The computer 309 collects and processes the received data to obtain the charge distribution at the gas-solid interface of the insulating material.

[0075] Specifically, the piezoelectric sensor 306 is used to convert the acoustic signal into a voltage signal, the signal amplifier 307 is used to amplify the voltage signal, the oscilloscope 308 is used to display the voltage signal waveform, and the computer 309 is used for data acquisition and processing, outputting the real-time charge distribution of the gas-solid interface.

[0076] In one embodiment, the pulse source is a nanosecond pulse source; the coupling resistor is 50Ω, and the protection resistor is greater than 5MΩ. The pulse power and pulse width of the pulse source can be adjusted according to experimental requirements. For example, the pulse source can output a pulse voltage signal with a pulse width of 5–20ns and an amplitude of 200–1kV. The DC source can output a DC voltage signal of 0–10kV.

[0077] Among them, such as Figure 4 As shown, Figure 4 This is a structural diagram of an electroacoustic pulse measurement system for the gas-solid interface charge of a solid insulating material when the test electrodes are placed.

[0078] The amplitude of the space charge waveform is proportional to the electric field applied to the plate sample. When testing with only the test electrode, the initial electric field applied to the plate sample is unknown, making it impossible to calibrate the amplitude of the test waveform and affecting subsequent analysis and research. Therefore, it is necessary to use a discharge electrode in conjunction to obtain the initial electric field applied to the plate sample during testing.

[0079] The following describes the measurement method corresponding to the electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials through a specific embodiment. Figure 5 As shown, Figure 5 This is a schematic diagram of the electroacoustic pulse measurement method for the gas-solid interface charge of a solid insulating material according to the present invention, which specifically includes the following steps:

[0080] S501, pulse excitation and DC excitation are applied to the discharge electrode simultaneously through the external circuit unit so that the voltage generated after the discharge electrode is excited is applied to the plate sample. The first space charge waveform signal is determined by acquiring the acoustic signal generated after the plate sample is energized by the signal acquisition unit.

[0081] Before the formal test, a discharge electrode test is performed to fully discharge the gas between the discharge electrode and the plate sample. At this time, it can be assumed that the voltage applied to the discharge electrode is fully applied to the plate sample. The space charge waveform signal collected at this time is the first space charge waveform signal, which can be used as the calibration waveform.

[0082] S502, the discharge electrode is replaced with a test electrode, and the same excitation as that used during the discharge electrode test is applied to the test electrode through the external circuit unit. The second space charge waveform distribution is determined based on the acoustic signal generated by the flat plate sample under the corresponding test electrode acquired by the signal acquisition unit.

[0083] Replace the discharge electrode with the test electrode and apply the same voltage as when testing the discharge electrode. Collect the space charge waveform signal at this time as the second space charge waveform distribution, and use the second space charge waveform distribution as the test waveform.

[0084] It should be noted that the voltage generated after the test electrode is excited is applied not only to the plate sample, but also to the gas between the test electrode and the plate sample. The collected acoustic signal is the acoustic signal generated by the gas and the plate sample after the voltage is applied.

[0085] S503, the second space charge waveform signal is calibrated by the first space charge waveform signal to obtain the charge distribution at the gas-solid interface of the insulating material.

[0086] The insulating materials include solid insulation (plate sample) and gas insulation, and the gas-solid interface charge distribution of the insulating materials includes the interface charge distribution of the plate sample and the gas insulation.

[0087] In one embodiment, calibrating a second space charge waveform signal using a first space charge waveform signal to obtain the charge distribution at the gas-solid interface of the insulating material includes: determining the initial electric field applied to the flat plate sample when acquiring the second space charge waveform signal based on the initial electric field applied to the flat plate sample when acquiring the first space charge waveform signal, the amplitude of the first space charge waveform signal, and the amplitude of the second space charge waveform signal; calibrating the amplitude of the second space charge waveform signal during signal processing based on the initial electric field applied to the flat plate sample when acquiring the second space charge waveform signal; and obtaining the charge distribution at the gas-solid interface of the insulating material based on the calibrated amplitude of the second space charge waveform signal.

[0088] Specifically, when acquiring the first space charge waveform signal, the initial electric field applied to the plate sample is known, denoted as E0, and the amplitude of the first space charge waveform signal is denoted as P0. When acquiring the second space charge waveform signal, the initial electric field applied to the plate sample is denoted as E1, and the amplitude of the second space charge waveform signal is known, denoted as P1. Then, E1 = (E0·P1) / P0. After obtaining the initial electric field during the test electrode test, the amplitude of the second space charge waveform signal can be calibrated during signal processing, and the accurate space charge distribution at the interface between the plate sample and the air gap can be obtained.

[0089] The method for obtaining the initial electric field applied to the plate sample when acquiring the first space charge waveform signal includes: determining the ratio of the voltage applied to the discharge electrode to the thickness of the plate sample as the initial electric field applied to the plate sample when acquiring the first space charge waveform signal.

[0090] In one embodiment, the present invention also provides a method for measuring the electroacoustic pulse charge at the gas-solid interface of a solid insulating material, the method comprising the following steps:

[0091] S601, Construct an electroacoustic pulse measurement system for the gas-solid interface charge of solid insulating materials, including an external circuit unit, an electrode unit, and a signal acquisition unit. Among them, the electrode unit first selects a discharge electrode for testing.

[0092] S602: Place the electrode unit in the gas environment required for the test, connect the circuit, and turn on the oscilloscope and computer.

[0093] S603, turn on the pulse source and DC source, and adjust the specific voltage parameters according to the test requirements.

[0094] S604, adjust the oscilloscope to find the space charge waveform signal, and use the computer to collect the signal at this time as the calibration waveform.

[0095] S605, replace the discharge electrode with the test electrode, repeat steps S602 to S604, and use a computer to collect the signal at this time as the test waveform.

[0096] S606 performs corresponding calibration and waveform recovery processing on the computer to obtain the real-time charge distribution at the gas-solid interface of the insulating material.

[0097] This invention is based on the principle of measuring space charge in solid materials using the PEA method. By improving the electrode structure and data correction, it enables the measurement of gas-solid interface charge in insulating materials under different conditions. This helps to study the characteristics and influence of charge accumulation at the gas-solid interface, elucidates the surface discharge mechanism at the gas-solid interface, and further guides the selection and optimization of GIL insulator materials. It provides a new method for future research on the surface flashover process and insulation characteristics of insulators in high-voltage gas-insulated equipment. It has the advantages of simple structure, low cost, and high sensitivity.

[0098] When applying the electroacoustic pulse measurement method for the gas-solid interface charge of solid insulating materials provided by this invention, it is not necessary to consider... Figure 5 The steps shown are executed in sequence. The specific execution order of each step can be determined as needed, and this invention does not impose any restrictions on it.

[0099] The above describes one or more embodiments of the electroacoustic pulse measurement method for the gas-solid interface charge of solid insulating materials. Based on the same idea, the present invention also provides a corresponding electroacoustic pulse measurement device for the gas-solid interface charge of solid insulating materials, such as... Figure 6 As shown.

[0100] Figure 6 This is a schematic diagram of an electroacoustic pulse measurement device for the gas-solid interface charge of a solid insulating material provided by the present invention. The device 600 includes:

[0101] The first excitation module 601 is used to simultaneously apply pulse excitation and DC excitation to the discharge electrode through the external circuit unit, so that the voltage generated after the discharge electrode is excited is applied to the plate sample.

[0102] The first acquisition module 602 is used to acquire the acoustic signal generated after the plate sample is subjected to voltage by the signal acquisition unit, and determine the first space charge waveform signal.

[0103] The second excitation module 603 is used to replace the discharge electrode with the test electrode and apply the same excitation to the test electrode as when testing the discharge electrode through the external circuit unit;

[0104] The second acquisition module 604 is used to determine the second space charge waveform distribution based on the acoustic signal generated by the flat plate sample under the corresponding test electrode acquired by the signal acquisition unit.

[0105] The calibration module 605 is used to calibrate the second space charge waveform signal through the first space charge waveform signal to obtain the charge distribution at the gas-solid interface of the insulating material.

[0106] For specific limitations on the electroacoustic pulse measurement device for the gas-solid interface charge of solid insulating materials, please refer to the limitations on the electroacoustic pulse measurement method for the gas-solid interface charge of solid insulating materials mentioned above, which will not be repeated here.

[0107] The present invention also provides a computer-readable storage medium storing a computer program that can be used to execute the above-described... Figure 5 A method for measuring the electroacoustic pulse charge at the gas-solid interface of solid insulating materials is provided.

[0108] The present invention also provides Figure 7 The schematic diagram of the computer device shown is as follows: Figure 7 As shown, at the hardware level, this computer device includes a processor, internal bus, network interface, memory, and non-volatile memory, and may also include other hardware required for business operations. The processor reads the corresponding computer program from the non-volatile memory into memory and then executes it to achieve the above. Figure 5 A method for measuring the electroacoustic pulse charge at the gas-solid interface of solid insulating materials is provided.

[0109] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0110] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this invention.

Claims

1. An electroacoustic pulse measurement system for the gas-solid interface charge of a solid insulating material, characterized in that, include: The system comprises an external circuit unit, an electrode unit, and a signal acquisition unit; the electrode unit includes a working electrode, an epoxy plate, a shielding shell, an epoxy pad, a flat sample, and a lower electrode. The external circuit unit is detachably connected to the working electrode, which is detachably embedded in the epoxy board. The epoxy board and the shielding shell are connected and fixed. The working electrode, epoxy board, and shielding shell are concentric, and the lowest point of the working electrode and the lowest point of the shielding shell are on the same horizontal plane. The epoxy pad is sandwiched between the shielding shell and the flat plate sample, and the thickness of the epoxy pad is the height of the air gap between the working electrode and the flat plate sample. The flat plate sample is attached to the lower electrode, which is grounded and connected to the signal acquisition unit. The working electrode is a discharge electrode or a test electrode. The discharge electrode is an electrode with uniformly distributed needle tips, and the test electrode is a flat plate electrode. The discharge electrode and the test electrode are identical in all other dimensions and materials. The external circuit unit is used to simultaneously apply pulse excitation and DC excitation to the discharge electrode or the test electrode, respectively. The working electrode is used to transmit a voltage signal after being excited and to apply the voltage signal to the plate sample; The signal acquisition unit is used to acquire the acoustic signal generated when the plate sample is subjected to voltage, and to obtain the charge distribution at the gas-solid interface of the insulating material based on the acoustic signal. When measuring the charge distribution at the gas-solid interface of insulating materials, the discharge electrode is used as the working electrode. After the signal acquisition unit acquires the acoustic signal generated by the discharge electrode, it replaces the discharge electrode with the test electrode. The signal acquisition unit then acquires the acoustic signal generated by the test electrode and obtains the charge distribution at the gas-solid interface of the insulating material based on the two acquired acoustic signals.

2. The system according to claim 1, characterized in that, The external circuit unit includes a pulse source, a capacitor, a coupling resistor, a protection resistor, and a DC source; one end of the pulse source is connected to one end of the coupling resistor and one end of the capacitor, the other end of the pulse source is grounded, the other end of the coupling resistor is grounded, one end of the DC source is connected to one end of the protection resistor, the other end of the DC source is grounded, and the other end of the capacitor and the other end of the protection resistor are both connected to the discharge electrode or the test electrode.

3. The system according to claim 1, characterized in that, The signal acquisition unit includes a piezoelectric sensor, a signal amplifier, an oscilloscope, and a computer; the piezoelectric sensor is connected to the oscilloscope via the signal amplifier, and the oscilloscope is connected to the computer. The piezoelectric sensor converts the acoustic signal generated when the plate sample is subjected to voltage into a voltage signal. The voltage signal is amplified by the signal amplifier and displayed on the oscilloscope. The oscilloscope then transmits the display data to the computer. The computer collects and processes the received data to obtain the charge distribution at the gas-solid interface of the insulating material.

4. The system according to claim 1, characterized in that, The electrode unit is placed in a sealed environment.

5. The system according to claim 1, characterized in that, The diameters of the discharge electrode and the test electrode are both smaller than the inner diameter of the epoxy mat layer.

6. The system according to claim 1, characterized in that, The flat plate sample is an epoxy resin or other polymer film.

7. The system according to claim 1, characterized in that, The pulse source is a nanosecond pulse source; the coupling resistor is 50Ω, and the protection resistor is greater than 5MΩ.

8. A method for measuring the electroacoustic pulse charge at the gas-solid interface of a solid insulating material, characterized in that, The method is applied to the system according to any one of claims 1-7; the method includes: The external circuit unit simultaneously applies pulse excitation and DC excitation to the discharge electrode so that the voltage generated after the discharge electrode is excited is applied to the plate sample. The first space charge waveform signal is determined by acquiring the acoustic signal generated after the plate sample is subjected to voltage by the signal acquisition unit; The discharge electrode is replaced with a test electrode, and the same excitation as that used when testing the discharge electrode is applied to the test electrode through the external circuit unit; The second space charge waveform distribution is determined based on the acoustic signal generated by the flat plate sample under the corresponding test electrode acquired by the signal acquisition unit. The charge distribution at the gas-solid interface of the insulating material is obtained by calibrating the second space charge waveform signal using the first space charge waveform signal.

9. The method according to claim 8, characterized in that, The step of calibrating the second space charge waveform signal using the first space charge waveform signal to obtain the charge distribution at the gas-solid interface of the insulating material includes: The initial electric field applied to the flat plate sample when acquiring the first space charge waveform signal is determined based on the initial electric field applied to the flat plate sample when acquiring the second space charge waveform signal, the amplitude of the first space charge waveform signal, and the amplitude of the second space charge waveform signal. The amplitude of the second space charge waveform signal during signal processing is calibrated based on the initial electric field applied to the flat plate sample when the second space charge waveform signal is acquired. The charge distribution at the gas-solid interface of the insulating material is obtained based on the amplitude of the calibrated second space charge waveform signal.

10. The method according to claim 9, characterized in that, The method for obtaining the initial electric field applied to the flat plate sample when acquiring the first space charge waveform signal includes: The ratio of the voltage applied to the discharge electrode to the thickness of the plate sample is determined as the initial electric field applied to the plate sample when acquiring the first space charge waveform signal.

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