A method of testing the electrical conductivity of a gas in a gas-solid composite insulation system and related apparatus

Abstract

The application discloses a kind of test method and related equipment to gas-solid composite insulation system gas conductance, method includes: obtaining target gas at target air pressure and target temperature gas-solid interface intrinsic response signal and target electric field different time space charge signal and bulk charge density signal;According to bulk charge density signal and intrinsic response signal, the surface charge density signal of gas-solid interface is determined, according to time window and surface charge density signal, average interface charge change rate, gas side time average equivalent electric field and solid side time average equivalent electric field are determined;The conductivity of solid insulating material at target temperature and target electric field is obtained, and the equivalent conductivity of gas in time window is calculated according to conductivity, average interface charge change rate, gas side time average equivalent electric field and solid side time average equivalent electric field.The application embodiment can improve the accuracy of gas-solid composite insulation system gas conductance test.The application can be widely applied in electrical testing technical field.

Description

Technical Field

[0001] This application relates to the field of electrical testing technology, and in particular to a method and related equipment for testing the gas conductivity in a gas-solid composite insulation system. Background Technology

[0002] High-voltage direct current (HVDC) transmission is a crucial technology for achieving long-distance, high-capacity power transmission and inter-regional power grid interconnection. Compared to traditional overhead transmission lines, gas-insulated direct current (GIL) lines offer advantages such as large transmission capacity, small footprint, less susceptibility to external environmental influences, and high operational reliability. They show promising application prospects in offshore wind power grid connection, high-density urban power transmission, and power transmission in complex environments.

[0003] The insulation system of a DC GIL (Gas Insulator) typically consists of a gaseous insulating medium and solid insulating components, forming a gas-solid composite insulation structure. Under DC voltage, the electric field distribution within the insulation system is primarily controlled by the conductivity of the dielectric. The conductivity of both the gaseous medium and the solid insulating material is affected by factors such as electric field strength, temperature, and gas pressure, exhibiting significant nonlinear characteristics. When there is a difference in conductivity between the gaseous medium and the solid insulating material, charge carriers tend to be blocked and accumulate at the gas-solid interface, forming interface charges and causing local electric field distortion.

[0004] In actual operation, DC GILs may be in complex multi-physics coupled environments. For example, the external environment of the equipment may be subjected to low temperatures such as high latitudes and high altitudes, while the internal central conductor will generate significant heat during heavy load operation, thus creating a temperature gradient within the insulation system. Simultaneously, to ensure insulation strength, the GIL typically requires a certain pressure of insulating gas, typically ranging from 0.4 MPa to 0.8 MPa. The combined effects of temperature, electric field, and gas pressure further influence the conductivity characteristics of the gaseous medium and the solid insulating material, making the charge accumulation behavior at the gas-solid interface more complex.

[0005] The accumulation of charge at the gas-solid interface can cause distortion of the electric field near the interface, which in severe cases may induce surface discharge or surface flashover in solid insulators, leading to insulation failure. Therefore, obtaining the nonlinear conductivity parameters of the gas medium under different temperatures, pressures, and electric fields is of great significance for studying the charge transport laws, interface charge accumulation mechanisms, and insulation structure optimization in DC GIL gas-solid composite insulation systems.

[0006] However, existing gas conductivity testing methods are often insufficient to evaluate the nonlinear conductivity parameters of gases under complex conditions such as wide temperature ranges, high gas pressures, and high DC field strengths, taking into account the dynamic charge behavior at the gas-solid interface. Especially in gas-solid composite insulation systems, gas conductivity is coupled with the conductivity of the solid insulating material, interfacial charge accumulation, and applied voltage boundary conditions, making it difficult for traditional testing methods to accurately reflect the conductivity characteristics of the gas medium under complex operating conditions. Summary of the Invention

[0007] The main objective of this application is to provide a method and related equipment for testing the gas conductivity in a gas-solid composite insulation system, aiming to improve the accuracy of gas conductivity testing in such systems.

[0008] To achieve the above objectives, one aspect of this application proposes a method for testing the gas conductivity in a gas-solid composite insulation system, the method comprising the following steps: The intrinsic response signal of the gas-solid interface of the target gas at the target pressure and target temperature and the space charge signal of the target electric field at different times are obtained, and the space charge signal is preprocessed to obtain the volume charge density signal. The surface charge density signal of the gas-solid interface is determined based on the volume charge density signal and the intrinsic response signal. A time window is determined based on the surface charge density signal. The average interfacial charge change rate, the time-averaged equivalent electric field on the gas side, and the time-averaged equivalent electric field on the solid side are determined based on the time window and the surface charge density signal. Obtain the conductivity of the solid insulating material at the target temperature and target electric field, and calculate the gas equivalent conductivity within the time window based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side, and the time-averaged equivalent electric field on the solid side.

[0009] In some embodiments, determining the surface charge density signal of the gas-solid interface based on the volume charge density signal and the intrinsic response signal includes: The region where the gas-solid interface peak is located is determined based on the volume charge density signal. The difference between the volume charge density signal and the intrinsic response signal is integrated in the region where the gas-solid interface peak is located to obtain the surface charge density signal of the gas-solid interface.

[0010] In some embodiments, determining the time window based on the surface charge density signal includes: The time window is determined based on the evolution characteristics of the surface charge density signal; the evolution characteristics include a rapid accumulation stage of interface charge, a slow stabilization stage, or a quasi-steady state stage.

[0011] In some embodiments, the average rate of change of interfacial charge is determined by the following method: The surface charge density at the start time and the surface charge density at the end time are determined based on the time window and the surface charge density signal. The average rate of change of interface charge is determined based on the surface charge density at the start time, the surface charge density at the end time, and the time window.

[0012] In some embodiments, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side are determined by the following method: The equivalent average electric field on the gas side and the equivalent average electric field on the solid side are determined based on the surface charge density signal, voltage boundary conditions, and gas-solid interface electric displacement boundary conditions. The time-averaged equivalent electric field on the gas side is determined based on the time window and the equivalent average electric field on the gas side; The time-averaged electric field on the solid side is determined based on the time window and the equivalent average electric field on the solid side.

[0013] In some embodiments, the method further includes: Obtain the gas equivalent conductivity and gas-side time-averaged equivalent electric field for different target gas pressures, temperatures, and electric fields; By fitting the gas equivalent conductivity and the time-averaged equivalent electric field on the gas side for different target gas pressures, target temperatures, and target electric fields, the nonlinear conductivity characteristics of the gas in the gas-solid composite insulation system are obtained.

[0014] To achieve the above objectives, another aspect of this application provides a testing device for the gas conductivity of a gas-solid composite insulation system, the device comprising: The first module is used to acquire the intrinsic response signal of the gas-solid interface of the target gas at the target pressure and target temperature and the space charge signal of the target electric field at different times, and to preprocess the space charge signal to obtain the volume charge density signal. The second module is used to determine the surface charge density signal of the gas-solid interface based on the volume charge density signal and the intrinsic response signal, determine the time window based on the surface charge density signal, and determine the average interface charge change rate, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side based on the time window and the surface charge density signal. The third module is used to obtain the conductivity of the solid insulating material at the target temperature and the target electric field, and to calculate the gas equivalent conductivity within the time window based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side.

[0015] To achieve the above objectives, another aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0016] To achieve the above objectives, another aspect of the embodiments of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0017] To achieve the above objectives, another aspect of this application provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0018] The embodiments of this application include at least the following beneficial effects: This application provides a method, apparatus, electronic device, storage medium, and program product for testing the gas conductivity in a gas-solid composite insulation system. This method acquires the intrinsic response signal of the gas-solid interface and the space charge signal of the target electric field at different times under target gas pressure and target temperature. The space charge signal is preprocessed to obtain a volume charge density signal. The surface charge density signal of the gas-solid interface is determined based on the volume charge density signal and the intrinsic response signal. A time window is determined based on the surface charge density signal. The average interface charge change rate and the gas-side time average are determined based on the time window and the surface charge density signal. The equivalent electric field and the time-averaged equivalent electric field on the solid side are obtained. The conductivity of the solid insulating material at the target temperature and target electric field is obtained. Based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side, the equivalent conductivity of the gas within the time window is calculated. By measuring the dynamic change of surface charge density at the gas-solid interface in situ, and combining the surface charge conservation equation, the calculation model of the equivalent average electric field on both sides of the gas and solid, and the conductivity measurement results of the solid insulating material, the equivalent conductivity and nonlinear conductivity parameters of the gas medium under different temperatures, pressures and electric field intensities are obtained by inverse solving, thereby improving the accuracy of gas conductivity testing in gas-solid composite insulation systems. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the gas-solid interface charge (PEA) measurement system provided in the embodiments of this application; Figure 2 This is a flowchart of a method for testing the gas conductivity in a gas-solid composite insulation system, provided in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of the three-electrode conductivity testing system provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the device for testing the gas conductivity in a gas-solid composite insulation system provided in the embodiments of this application; Figure 5 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0021] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0022] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0024] Pulsed Electro-Acoustic Method (PEA) is a non-destructive space charge measurement technique widely used to evaluate charge accumulation and transport behavior within insulating materials, particularly dielectrics in high-voltage DC equipment. The basic principle is as follows: A high-voltage electric pulse (nanosecond level) is applied across the sample and superimposed on a DC bias field. This pulsed electric field exerts an instantaneous mechanical force (Coulomb force) on the space charge accumulated within the sample, causing these charges to undergo minute displacements and thus emit stress acoustic waves outwards. The propagation speed of the acoustic waves within the sample is position-dependent. By receiving the signal through a piezoelectric sensor at the end and converting it into a voltage waveform, the charge density distribution curve as a function of thickness can be derived.

[0025] In related technologies, the gas conductivity measurement method typically employs the direct current measurement method based on Ohm's law. This method calculates the gas conductivity by applying a DC voltage across the gas gap and measuring the conduction current flowing through the gas. However, when the gas is not discharged or has a low degree of ionization, its conduction current is usually in the picoampere to nanoampere range, resulting in extremely low signal amplitude. This makes it susceptible to the influence of factors such as stray capacitance charging and discharging in the test circuit, electrode polarization, leakage current from the insulation support, and external electromagnetic interference. Consequently, the directly measured current cannot accurately reflect the bulk conduction characteristics of the gas medium itself.

[0026] Meanwhile, in DC gas-solid composite insulation systems, the gaseous medium, solid insulating material, and the gas-solid interface charge accumulation process are mutually coupled. Traditional direct current measurement methods often struggle to distinguish the contributions of different physical processes such as gas conduction, solid leakage current, and dynamic accumulation of interface charges, and are difficult to accurately obtain the nonlinear conductivity parameters of the gaseous medium under complex conditions such as wide temperature ranges, varying gas pressures, and high DC field strengths. Therefore, existing technologies are insufficient to meet the requirements for insulation characteristic analysis and structural optimization of DC GIL and other gas-solid composite insulation equipment under complex operating conditions.

[0027] The purpose of this invention is to overcome the problems in existing technologies, such as the difficulty in accurately measuring weak gas conduction current, the difficulty in decoupling multiple physical processes in gas-solid composite insulation systems, and the difficulty in obtaining nonlinear conductivity parameters of gases under complex temperature and pressure environments. This invention provides a gas conductivity testing method based on a gas-solid interface (PEA) measurement system for insulating materials under high temperature and high pressure. This method involves in-situ measurement of the dynamic change in surface charge density at the gas-solid interface, combined with the interface charge dynamics equation, the equivalent average electric field calculation model on both sides of the gas and solid surfaces, and the conductivity measurement results of the solid insulating material. The equivalent conductivity and nonlinear conductivity parameters of the gas medium under different temperatures, pressures, and electric field intensities are obtained through inverse solving.

[0028] The method of this invention can reduce the influence of stray capacitance, electromagnetic interference and leakage current on the test results in traditional direct measurement of weak current. It can more reasonably characterize the equivalent conduction characteristics of gas medium in gas-solid composite insulation structure under actual DC operating conditions, and provide test basis and parameter support for the analysis of space charge accumulation law at gas-solid interface, the optimized design of composite insulation structure and the assessment of surface flashover risk.

[0029] The gas conductivity testing method provided in this application relates to the field of information technology. The gas conductivity testing method provided in this application can be applied to a terminal, a server, or software running on a terminal or server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, smart speaker, smartwatch, or vehicle terminal, but is not limited to these. The server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network. The software can be an application implementing the gas conductivity testing method, but is not limited to the above forms.

[0030] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0031] This application provides a method for testing the gas conductivity under high temperature and high pressure based on a gas-solid interface (PEA) measurement system for insulating materials. The basic principle is: when a DC high voltage is applied to a gas-solid medium composite system, the conductivity of the gas and solid... ) and dielectric constant ( There are differences, and charge carriers will be blocked and accumulate at the gas-solid interface.

[0032] According to the law of conservation of charge, the equation for continuity of current... Integrating at the gas-solid interface, we can obtain the kinetic equation for the surface charge density σ at the interface:

[0033] in, and For the normal components of the current density on the gas side and the solid side; The net increase or decrease in interfacial charge due to lateral migration is due to the surface conductivity of the insulating dielectric. Extremely low, and the applied electric field of the present invention is perpendicular to the interface, with the interface tangential electric field. Therefore, this item can usually be ignored.

[0034] Therefore, the rate of change of surface charge density σ(t) depends on the difference between the conduction current density in the air gap and the solid medium:

[0035] in, and Let be the equivalent average electric field strength on the gas side and the solid side at time t, respectively. This represents the equivalent conductivity of a gas. Within the same temperature and a relatively narrow electric field range, the conductivity of a solid can be... It can be approximated as a constant; if the conductivity of the solid changes significantly with the electric field or temperature, it should be obtained in advance using the three-electrode method. The relationship is established, and the solid conductivity under the corresponding conditions is substituted into the inversion process. .

[0036] See Figure 1 The space charge testing system used in this invention is a gas-solid interface charge (PEA) measurement system. The test structure consists of a power supply module (high voltage DC source 1-4, current limiting resistor 1-3, nanopulse 1-2, coupling capacitor 1-1), a gas gap, a solid insulating sample, upper and lower electrodes, an acoustic coupling layer, a piezoelectric sensor, and a signal acquisition system (preamplifier 1-5).

[0037] The gas gap thickness is adjusted using insulating gaskets. Solid insulating samples can be made of insulating materials such as epoxy resin, polyethylene, polypropylene, polyimide, and silicone rubber. The gas medium can be air, nitrogen, carbon dioxide, sulfur hexafluoride substitute gas, dry air, or other engineering insulating gases. The test chamber has temperature, pressure, and humidity control capabilities, enabling testing over a wide temperature range, at different pressures, and with different gas compositions.

[0038] The PEA pulse voltage induces transient acoustic responses at the gas-solid interface, electrode interface, and space charge within the solid. The acoustic waves primarily propagate to the piezoelectric sensor via the solid side. Since the acoustic impedance of the gas is much lower than that of the solid, acoustic signals from the gas cannot effectively penetrate the interface; therefore, this scheme uses the gas-solid interface charge as the primary measurable object.

[0039] The volume charge density of a medium can be measured using a gas-solid interface PEA space charge measurement system. With the grounding electrode at x=0, the direction points towards the high-voltage electrode along the thickness; the thickness of the solid dielectric is d. s The gas gap thickness is dg, and the applied voltage is V.

[0040] See Figure 2 This application provides a method for testing the gas conductivity in a gas-solid composite insulation system, the method including the following steps S101 to S103.

[0041] Step S101: Obtain the intrinsic response signal of the gas-solid interface of the target gas at the target pressure and target temperature and the space charge signal of the target electric field at different times, and preprocess the space charge signal to obtain the volume charge density signal. Step S102: Determine the surface charge density signal of the gas-solid interface based on the volume charge density signal and the intrinsic response signal; determine the time window based on the surface charge density signal; and determine the average interface charge change rate, the time-averaged equivalent electric field on the gas side, and the time-averaged equivalent electric field on the solid side based on the time window and the surface charge density signal. Step S103: Obtain the conductivity of the solid insulating material at the target temperature and target electric field, and calculate the gas equivalent conductivity within the time window based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side, and the time-averaged equivalent electric field on the solid side.

[0042] Before calculating the surface charge density signal at the gas-solid interface, the initial interface response of the gas-solid composite structure should be calibrated and subtracted. Due to significant differences in dielectric constant, acoustic impedance, sound velocity, and sound attenuation characteristics between the gaseous medium and the solid insulating material, a certain amplitude interface response may still appear in the PEA measurement waveform even before significant free charge accumulation occurs at the gas-solid interface. This initial interface response does not entirely originate from actual interface free charge, but may be caused by the electric field distribution resulting from the difference in dielectric constant between the gas and solid media, the polarization response under the action of a pulsed electric field, the sound wave reflection and transmission caused by the abrupt change in acoustic impedance at the gas-solid interface, and the pulse response of the test system itself.

[0043] Before the formal pressurization measurement, this invention first acquires the initial PEA waveform of the gas-solid interface under conditions of low field and short-term pressurization, where no significant charge migration occurs, and records it as... This initial intrinsic response signal was then used as the intrinsic response signal of the gas-solid interface in the initial state. Subsequently, this initial intrinsic response signal was removed from the PEA waveforms obtained at different pressurization times to avoid misinterpreting interface peaks caused by dielectric voltage division, acoustic reflection, system response, or initial polarization as actual interface charge accumulation.

[0044] After the pressure test, the collected signal is deconvolved, acoustic attenuation compensated, and the initial state interface intrinsic response signal is subtracted. Then, the corrected volume charge density distribution signal was obtained. .in, Represents time t, x The corrected volume charge density at the location.

[0045] See Figure 3 The three-electrode conductivity testing system includes a high-voltage electrode 3-1, a measuring electrode 3-2, a protective electrode 3-3, a test sample 3-4, a protective resistor 3-5, a test power supply, an oscilloscope, etc. This invention uses the three-electrode method to measure the conductivity of solid insulating materials: a DC voltage is applied to the insulating material... U Then, the electrode current was collected and measured. I S According to the formula: The conductivity of solid insulating materials can be obtained. In the formula, d For the sample thickness, U To apply voltage, S This represents the effective area of ​​the test electrode.

[0046] The specific testing procedure for the gas conductivity in a gas-solid composite insulation system is as follows: Step 1: Build a gas-solid interface (PEA) measurement system, including an external circuit unit, an electrode unit, a signal acquisition unit, and a high and low pressure test chamber.

[0047] Step 2: Fill the high and low pressure test chamber with the target gas, set the required gas pressure environment and temperature, and keep it at that temperature for at least one hour to allow the test chamber, gas medium and solid insulation sample to reach a stable state.

[0048] Step 3: Acquire the initial PEA waveform under low-field or short-time pressurization conditions to obtain the intrinsic response signal of the gas-solid interface. .

[0049] Step 4: Perform continuous PEA measurement under the target DC voltage, and collect space charge waveforms at set time intervals to obtain space charge signals.

[0050] Step 5: Perform denoising, time correction, deconvolution, acoustic attenuation compensation, and initial interface response subtraction on the space charge signal to obtain the corrected volume charge density. .

[0051] Step 6: Integrate the window containing the gas-solid interface peak to obtain the interfacial surface charge density σ(t), and obtain the curve of σ(t) changing with time.

[0052] Step 7: Select a time window based on the characteristics of interface charge evolution. t 1 ,t 2).

[0053] Step 8: Calculate the average rate of change of interface charge within the time window based on the interface surface charge densities σ(t1) and σ(t2) at the start and end times of the time window. .

[0054] Step 9: Substitute σ(t) at each sampling time within the time window into the applied voltage boundary condition and the gas-solid interface electric displacement boundary condition to calculate the equivalent average electric field on the gas side at the corresponding time. Equivalent average electric field on the solid side .

[0055] Step 10: Within the time window and Time averaging is performed to obtain the time-averaged equivalent electric field on the gas side. and solid-side time-averaged equivalent electric field .

[0056] Step 11: Measure the conductivity of the solid insulating material under corresponding temperature and electric field conditions using the three-electrode method. If the conductivity of a solid changes significantly with electric field strength or temperature, then... .

[0057] Step 12: Calculate the average rate of change of interfacial charge. Gas-side time-averaged equivalent electric field Solid-side time-averaged equivalent electric field and solid conductivity Substitute into the above inversion formula to calculate the gas equivalent conductivity within this time window. .

[0058] The average electric field strength on both sides of the interface is obtained by combining the applied voltage boundary conditions. and The conductivity γ of the solid insulating material was measured using the three-electrode method. s Substitute into the equation We can obtain:

[0059] In some embodiments, determining the surface charge density signal of the gas-solid interface based on the volume charge density signal and the intrinsic response signal includes: The region where the gas-solid interface peak is located is determined based on the volume charge density signal; The surface charge density signal of the gas-solid interface is obtained by integrating the difference between the volume charge density signal and the intrinsic response signal in the region where the gas-solid interface peak is located.

[0060] The surface charge at the gas-solid interface appears as a sharp peak of a certain width on the volume charge distribution curve. Integrating along the thickness direction over the region containing the peak at the gas-solid interface yields the surface charge density at the gas-solid interface at a given moment. :

[0061] in, x s It is the integral boundary on the solid side of the interface peak. x g It is the integral boundary on the gas side of the interface peak, and both are located at the gas-solid interface. x =d s nearby.

[0062] In some embodiments, determining a time window based on a surface charge density signal includes: The time window is determined based on the evolution characteristics of the surface charge density signal; the evolution characteristics include the rapid accumulation stage of interface charge, the slow stabilization stage, or the quasi-steady state stage.

[0063] The time window can correspond to the rapid accumulation stage, slow stabilization stage, or quasi-steady state stage of interface charge. To ensure comparability of results under different test conditions, the same time window should be used as much as possible under different voltage, temperature, or air pressure conditions, or the time window corresponding to the same normalized charge stage should be used.

[0064] In some embodiments, the average rate of change of interfacial charge is determined by the following method: The surface charge density at the start and end times are determined based on the time window and the surface charge density signal. The average rate of change of interfacial charge is determined based on the surface charge density at the start time, the surface charge density at the end time, and the time window.

[0065] The interfacial surface charge density σ(t) obtained from PEA measurement is used to calculate the average rate of change of interfacial charge within the time window [t1, t2].

[0066] Where σ(t1) represents the surface charge density at the beginning and σ(t2) represents the surface charge density at the end. This represents the average rate of change of the surface charge density at the gas-solid interface within that time window.

[0067] In some embodiments, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side are determined by the following method: The equivalent average electric field on the gas side and the equivalent average electric field on the solid side are determined based on the surface charge density signal, voltage boundary conditions, and electric displacement boundary conditions at the gas-solid interface. The time-averaged equivalent electric field on the gas side is determined based on the time window and the equivalent average electric field on the gas side. The time-averaged equivalent electric field on the solid side is determined based on the time window and the equivalent average electric field on the solid side.

[0068] Under the one-dimensional approximation, the gas-side and solid-side potentials satisfy:

[0069] Using electric displacement vector boundary conditions:

[0070] Therefore, the electric field of the gas can be calculated as follows:

[0071] Solid electric field strength:

[0072] To reduce the impact of PEA measurement noise and numerical differentiation errors on the conductivity inversion results, this invention does not directly use the instantaneous electric field at a single moment for inversion. Instead, it calculates the time-averaged equivalent electric fields on the gas and solid sides within a selected time window [t1, t2], denoted as […]. and :

[0073]

[0074] The time window [t1, t2] can be selected according to the stage of interface charge evolution, such as the rapid accumulation stage, the slow stabilization stage, or the quasi-steady-state stage. To ensure comparability of results under different conditions, the same time window should be used as much as possible under different voltage, temperature, or air pressure conditions, or the time window corresponding to the same normalized charge stage should be used.

[0075] In some embodiments, the method further includes: Obtain the gas equivalent conductivity and gas-side time-averaged equivalent electric field for different target gas pressures, temperatures, and electric fields; By fitting the gas equivalent conductivity and the time-averaged equivalent electric field on the gas side for different target gas pressures, target temperatures, and target electric fields, the nonlinear conductivity characteristics of the gas in the gas-solid composite insulation system are obtained.

[0076] The method for testing the gas conductivity in a gas-solid composite insulation system also includes the following steps: Step 13: Change the applied voltage, temperature, gas pressure, or gas composition, and repeat the above test and inversion process to obtain results under different conditions. The correspondence between electric field strength, temperature, and air pressure.

[0077] Step 14: Based on the results obtained under different applied voltages and The data were fitted to obtain the nonlinear conductivity characteristics of the gas under specific temperature, pressure and gas composition conditions.

[0078] The embodiments of this application include at least the following beneficial effects: This application provides a method, apparatus, electronic device, storage medium, and program product for testing the gas conductivity in a gas-solid composite insulation system. This method acquires the intrinsic response signal of the gas-solid interface and the space charge signal of the target electric field at different times under target gas pressure and target temperature. The space charge signal is preprocessed to obtain a volume charge density signal. The surface charge density signal of the gas-solid interface is determined based on the volume charge density signal and the intrinsic response signal. A time window is determined based on the surface charge density signal. The average interface charge change rate and the gas-side time average are determined based on the time window and the surface charge density signal. The equivalent electric field and the time-averaged equivalent electric field on the solid side are obtained. The conductivity of the solid insulating material at the target temperature and target electric field is obtained. Based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side, the equivalent conductivity of the gas within the time window is calculated. By measuring the dynamic change of the surface charge density at the gas-solid interface in situ, and combining the interface charge dynamics equation, the calculation model of the equivalent average electric field on both sides of the gas and solid, and the conductivity measurement results of the solid insulating material, the equivalent conductivity and nonlinear conductivity parameters of the gas medium under different temperatures, pressures and electric field strengths are obtained by inverse solving, thereby improving the accuracy of gas conductivity testing in gas-solid composite insulation systems.

[0079] Please see Figure 4 This application also provides a testing device for the gas conductivity in a gas-solid composite insulation system, the device comprising: The first module is used to acquire the intrinsic response signal of the gas-solid interface of the target gas at the target pressure and target temperature and the space charge signal of the target electric field at different times, and to preprocess the space charge signal to obtain the volume charge density signal. The second module is used to determine the surface charge density signal of the gas-solid interface based on the volume charge density signal and the intrinsic response signal, determine the time window based on the surface charge density signal, and determine the average interface charge change rate, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side based on the time window and the surface charge density signal. The third module is used to obtain the conductivity of the solid insulating material at the target temperature and target electric field, and to calculate the gas equivalent conductivity within the time window based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side.

[0080] It is understood that the content of the above method embodiments is applicable to the present device embodiments. The specific functions implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0081] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0082] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0083] Please see Figure 5 , Figure 5 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes: The processor 501 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application. The memory 502 can be implemented as a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 502 can store the operating system and other applications. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 502 and is called and executed by the processor 501 using the methods described in the embodiments of this application. The input / output interface 503 is used to implement information input and output; The communication interface 504 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 505 transmits information between various components of the device (e.g., processor 501, memory 502, input / output interface 503, and communication interface 504); The processor 501, memory 502, input / output interface 503, and communication interface 504 are connected to each other within the device via bus 505.

[0084] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0085] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0086] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0087] It is understood that the content of the above method embodiments is applicable to the embodiments of this program product. The specific functions implemented by the embodiments of this program product are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0088] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0089] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0090] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0091] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0092] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0093] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0094] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0095] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0096] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0097] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0098] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0099] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for testing the gas conductivity in a gas-solid composite insulation system, characterized in that, The method includes the following steps: The intrinsic response signal of the gas-solid interface of the target gas at the target pressure and target temperature and the space charge signal of the target electric field at different times are obtained, and the space charge signal is preprocessed to obtain the volume charge density signal. The surface charge density signal of the gas-solid interface is determined based on the volume charge density signal and the intrinsic response signal. A time window is determined based on the surface charge density signal. The average interfacial charge change rate, the time-averaged equivalent electric field on the gas side, and the time-averaged equivalent electric field on the solid side are determined based on the time window and the surface charge density signal. Obtain the conductivity of the solid insulating material at the target temperature and target electric field, and calculate the gas equivalent conductivity within the time window based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side, and the time-averaged equivalent electric field on the solid side.

2. The method according to claim 1, characterized in that, Determining the surface charge density signal of the gas-solid interface based on the volume charge density signal and the intrinsic response signal includes: The region where the gas-solid interface peak is located is determined based on the volume charge density signal. The difference between the volume charge density signal and the intrinsic response signal is integrated in the region where the gas-solid interface peak is located to obtain the surface charge density signal of the gas-solid interface.

3. The method according to claim 1, characterized in that, Determining the time window based on the surface charge density signal includes: The time window is determined based on the evolution characteristics of the surface charge density signal; the evolution characteristics include a rapid accumulation stage of interface charge, a slow stabilization stage, or a quasi-steady state stage.

4. The method according to claim 1, characterized in that, The average rate of change of interfacial charge is determined by the following method: The surface charge density at the start time and the surface charge density at the end time are determined based on the time window and the surface charge density signal. The average rate of change of interface charge is determined based on the surface charge density at the start time, the surface charge density at the end time, and the time window.

5. The method according to claim 1, characterized in that, The time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side are determined by the following method: The equivalent average electric field on the gas side and the equivalent average electric field on the solid side are determined based on the surface charge density signal, voltage boundary conditions, and gas-solid interface electric displacement boundary conditions. The time-averaged equivalent electric field on the gas side is determined based on the time window and the equivalent average electric field on the gas side; The time-averaged electric field on the solid side is determined based on the time window and the equivalent average electric field on the solid side.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: Obtain the gas equivalent conductivity and gas-side time-averaged equivalent electric field for different target gas pressures, temperatures, and electric fields; By fitting the gas equivalent conductivity and the time-averaged equivalent electric field on the gas side for different target gas pressures, target temperatures, and target electric fields, the nonlinear conductivity characteristics of the gas in the gas-solid composite insulation system are obtained.

7. A testing device for the gas conductivity in a gas-solid composite insulation system, characterized in that, The device includes: The first module is used to acquire the intrinsic response signal of the gas-solid interface of the target gas at the target pressure and target temperature and the space charge signal of the target electric field at different times, and to preprocess the space charge signal to obtain the volume charge density signal. The second module is used to determine the surface charge density signal of the gas-solid interface based on the volume charge density signal and the intrinsic response signal, determine the time window based on the surface charge density signal, and determine the average interface charge change rate, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side based on the time window and the surface charge density signal. The third module is used to obtain the conductivity of the solid insulating material at the target temperature and the target electric field, and to calculate the gas equivalent conductivity within the time window based on the conductivity, the average rate of change of interface charge, the time-averaged equivalent electric field on the gas side and the time-averaged equivalent electric field on the solid side.

8. An electronic device, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

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