Electric Field Characteristics Research Articles

Discharge Modes Evolution Characteristics of Metal Particle on the Spacer Surface in AC Gas Insulated Switchgear

Abstract Flashover faults on gas insulated switchgear (GIS) insulators induced by metal particles occur frequently. Previous studies have obtained the characteristics of partial discharges (PDs) induced by metal particles on spacer surfaces, but these characteristics cannot explain the detection failure of ultra-high frequency (UHF) online monitoring. To enable further study of the PD characteristics induced by surface metal particles, the space electric field and a very-high-sensitivity pulse current (PC) measurement system were established. The electric field and PC characteristics of a PD induced by metal particle on the spacer surface of a 126 kV GIS were obtained. Two PD modes were found to be induced by surface metal particles. In addition to the typical pulse discharge (TP), there is a micro-discharge group (MG) mode with low apparent charge and long duration. The average apparent charge of the MG mode is approximately one-tenth of that of the TP at 0.4 pC. Its duration may extend to the millisecond level, causing significant distortion of the spatial electric field while hardly producing UHF signals. Moreover, increasing the applied voltage will increase the proportion of the MG within the total discharge, where this proportion can reach more than 90% before flashover, and the proportion of the discharge pulses that generates UHF signals is as low as 1%. The MG generation mechanism is analysed, the ion group stranded on the spacer surface by the TP changes the local electric field at the tip of the metal particle, which reduces the development length and apparent charge of the MG. Low apparent charge is cleared easily by the background electric field and thus the discharge interval is very short. This paper can provide an important basis for revealing the mechanism of GIS spacer surface discharge induced by metal particles and solving the effectiveness of PD monitoring devices.

Unveiling Spatial and Temporal Dynamics of Plasmon-Enhanced Localized Fields in Metallic Nanoframes through Ultrafast Electron Microscopy.

Plasmonic nanomaterials, particularly noble metal nanoframes (NFs), are important for applications such as catalysis, biosensing, and energy harvesting due to their ability to enhance localized electric fields and atomic efficiency via localized surface plasmon resonance (LSPR). Yet the fundamental structure-function relationships and plasmonic dynamics of the NFS are difficult to study experimentally and thus far rely predominately on computational methodologies, limiting their utilization. This study leverages the capabilities of ultrafast electron microscopy (UEM), specifically photon-induced near-field electron microscopy (PINEM), to probe the light-matter interactions within plasmonic NF structures. The effects of shape, size, and plasmonic coupling of Pt@Au core-shell NFs on spatial and temporal characteristics of plasmon-enhanced localized electric fields are explored. Importantly, time-resolved PINEM analysis reveals that the plasmonic fields around hexagonal NF prisms exhibit a spatially dependent excitation and decay rate, indicating a nuanced interplay between the spatial geometry of the NF and the temporal evolution of the localized electric field. These results and observations uncover nanophotonic energy transfer dynamics in NFs and highlight their potential for applications in biosensing and photocatalysis.

Electric Field Features and Charge Behavior in Oil-Pressboard Composite Insulation under Impulse Voltage

Oil-pressboard/paper insulation materials are essential in transformers for ensuring their safe and stable operation, primarily due to their roles in spatial electric field distribution and charge migration mechanisms. Current spatial distribution analyses rely on computational methods that lack empirical validation, particularly for oil-pressboard/paper composites. This study leverages the principles of the Kerr electro-optic effect to develop a rapid measurement platform for electric fields within oil-pressboard/paper insulation under impulse voltage conditions, which measures the spatial electric field characteristics using Cu-Cu and Al-Al electrodes under various scenarios: with asymmetric and symmetric pressboard coverage and different numbers of insulating paper layers. Findings indicated: (1) In asymmetric pressboard models, Cu-Cu electrodes exhibit a consistent peak electric field of approximately 16 kV/mm, while Al-Al electrodes show peak values of 18.13 kV/mm and −14.98 kV/mm. Charge density patterns are similar, with Cu-Cu at about 68 μC/m2 and Al-Al at 11.2 μC/m2 and −124.8 μC/m2. (2) Symmetric models present consistent peak electric fields and charge densities for both polarities. (3) Increasing insulating paper layers elevates electric field strengths. Both electrodes show the similar peak field of about 17 kV/mm with differing paper layers due to higher charge injection from the Al electrode. (4) Utilizing the Schottky effect and field emission principles, the study clarifies charge generation and migration mechanisms. These insights could provide a theoretical foundation for designing and verifying oil-pressboard/paper insulation structures in transformers.

Is short-offset frequency-domain controlled-source electromagnetic survey using an equatorial configuration a good choice on land?

The frequency-domain controlled-source electromagnetic (FD-CSEM) method can be used to collect data in both the large-offset plane-wave zones and the short-offset zone using an axial configuration within conductive marine environments. In contrast, the equatorial configuration is more commonly adopted for field surveys on land. However, selecting a suitable offset using an equatorial configuration on land remains a challenge. Therefore, the primary objective of this study was to choose a reasonable offset using an equatorial configuration on land. To this end, we compared the distribution and decay characteristics of the horizontal electric field. Additionally, we analyzed the detectability of the horizontal electric field to targets based on the root mean square (RMS) misfit and three-dimensional (3D) simulation at different offsets. The 3D simulation results show that the maximum normalized response at different offsets is similar, indicating that electric fields at different offsets share similar resolution limits. However, the horizontal electric field at small offsets (less than 3 times the target depth) only have the detectability for the target resistivity and are unable to make more precise distinctions on the target thickness. The detectability for the target thickness at very small offsets (about one time the target depth) is limited, as frequency sounding cannot be effectively established. A larger offset distance (larger than 4 to 6 times the target depth) is required when observing the vertical magnetic field compared to the horizontal electric field. Finally, we observed the electric field data at different offsets in the Kalatongke nickel–copper deposit in Xinjiang, China, which verifies our theoretical analysis.

Evolution of Characteristics of Vertical Electric Current and Magnetic Field in Active Regions of the Sun and their Relation to Powerful Flares

The study of evolution of magnetic field and electric currents in active regions of the Sun over a long-time interval is of interest for understanding the processes of accumulation and release of energy in them, leading to various phenomena that affect space weather. In this work, based on the photospheric vector magnetograms of the Helioseismic and Magnetic Imager instrument aboard the Solar Dynamics Observatory, an analysis was made of the evolution of a number of characteristics of the magnetic field and vertical electric current in three active regions 11158, 11675, and 12673 that produced class M and X flares, during the time from their origin in the Eastern hemisphere, during the passage through the solar disk, and until the disappearance near the Western limb with a step of 2 hours. The characteristics under consideration included: the power-law exponent of the probability density function of the absolute value of the vertical electric current density, the maximum of the absolute value of the vertical current density, the signed and unsigned total vertical currents and the unsigned total vertical and horizontal magnetic fluxes, the energy of the nonlinear force-free and potential magnetic fields, the free magnetic energy, and the number of islands with strong vertical current. Some regularities in the behaviour of the characteristics under consideration are found, in particular regarding the occurrence of solar flares. The correlation coefficients between pairs of these characteristics are calculated. Additionally, M. Aschwanden’s approach is shown to be promising for predicting the maximum X-ray class of a flare based on the calculation of the energy of the potential magnetic field in active regions. The results obtained can be used to predict powerful solar flares.

A Novel 5G Multi-mode Resonator and Filter with Symmetric Transmission Zeros

5G construction is becoming increasingly important. This paper introduces the theoretical basis of multi-mode filter, and on the basis of theoretical calculation and analysis, a novel 5G cavity multi-mode resonator and filter is designed by using ads/HFSS simulation software. The electric field characteristic of resonator is analyzed, and the mutual coupling between modes is realized by the way of screw perturbation. The electric field distributions of the mode is changed by adding tuning screws, two coupled degenerate modes act as two coupled resonators, so that the numbers of resonator can be reduced while keeping the resonance loop unchanged. For example, the characteristics of 3N section filter can be realized in the physical space of a traditional n-section filter by using three modes of a resonator, thus greatly reducing the volume of the filter. The results show that in the pass-band (3.5 GHz ~ 3.6 GHz): return loss > 17.9 dB, standing wave ratio < 1.29, insertion loss < 0.31 dB, a transmission zero point is introduced at 4 GHz on the right side of the pass-band, which makes the right side out of band attenuation rapidly. The filter has the advantages of small insertion loss, small size and good rejection of out of band, which can be applied to 5G band wireless communication system for better reliability.

Study of three-dimensional spatial diffuse discharge in contact electrode structure applied to air purification

In this work, based on the role of pre-ionization of the non-uniform electric field and its effect of reducing the collisional ionization coefficient, a diffuse dielectric barrier discharge plasma is formed in the open space outside the electrode structure at a lower voltage by constructing a three-dimensional non-uniform spatial electric field using a contact electrode structure. The air purification study is also carried out. Firstly, a contact electrode structure is constructed using a three-dimensional wire electrode. The distribution characteristics of the spatial electric field formed by this electrode structure are analyzed, and the effects of the non-uniform electric field and the different angles of the vertical wire on the generation of three-dimensional spatial diffuse discharge are investigated. Secondly, the copper foam contact electrode structure is constructed using copper foam material, and the effects of different mesh sizes on the electric field distribution are analyzed. The results show that as the mesh size of the copper foam becomes larger, a strong electric field region exists not only on the surface of the insulating layer, but also on the surface of the vertical wires inside the copper foam, i.e., the strong electric field region shows a three-dimensional distribution. Besides, as the mesh size increases, the area of the vertical strong electric field also increases. However, the electric field strength on the surface of the insulating layer gradually decreases. Therefore, the appropriate mesh size can effectively increase the discharge area, which is conducive to improving the air purification efficiency. Finally, a highly permeable stacked electrode structure of multilayer wire-copper foam is designed. In combination with an ozone treatment catalyst, an air purification device is fabricated, and the air purification experiment is carried out.

Enhanced peroxymonosulfate activation for emerging contaminant degradation via defect-engineered interfacial electric field in FeNC

Peroxymonosulfate (PMS) activation technology has important application value in treating emerging contaminant (ECs), but it still faces challenges in achieving efficient electron transfer and metal valence cycling. In this study, the interfacial electric field characteristics of FeNC catalysts were adjusted by introducing NC defects to affect the electron transfer process, thereby enhancing the catalytic performance of PMS. It is found that in the FeNC structure, the shift of the charge generates an interfacial electric field, which can promote the directional transfer of electrons. Through quantitative structure–activity relationship (QSAR) analysis, it was confirmed that the defect played a decisive role in regulating the interfacial electric field and improving the catalytic reaction efficiency. The interfacial electric field-mediated superexchange interaction realizes the electron donor effect of organic pollutants and the effective electron transfer between the Fe site, accelerates the electron cycling of the Fe site, and realizes the rapid and stable catalysis of PMS. The increase of the occupancy state distribution of d orbitals near the Fermi level provides favorable conditions for electron transitions and catalytic activation of PMS. ECs can be converted into environmentally friendly, non-toxic and harmless substances through. This defect-controlled interface electric field strategy realizes rapid electron directional transfer, which provides a new solution for improving the catalytic efficiency of PMS and the safe treatment of ECs in water.

Effect of High-Voltage Electrostatic Precipitator Dust Collection Plate Structure on Collection Efficiency.

To investigate the effect of changes in the dust collector structure on the flow field and electric field distribution resulting from the secondary flow generated by the corona discharge in the collector coupled with the main flow and to improve the dust collection efficiency of the ESP, a folding plate design has been adopted. A multiphysics-coupled corona discharge and flow field numerical model was analyzed to analyze the internal flow and electric field characteristics of linear flat plates and folded plates with three different pole configurations. The study indicates that the dust collecting plate's structure significantly affects the dust collector's internal flow field and electric field distribution within the dust collector. The near-plate electric field and flow field inside the folded plate type are superior to those of the linear flat electrostatic precipitator. With the augmentation of the inlet velocity, the ionic wind disturbance on the flow field inside the electrostatic precipitator channel gradually decreases. Additionally, the folding plate has a certain inhibitory effect on the influence of the ionic wind. At an inlet velocity of 0.5 m/s, the speed near the folding plate is approximately 20% lower than that of the traditional linear flat plate. The folding plate can effectively reduce the flow velocity near the dust collection plate, thereby reducing the occurrence of particle re-entrainment and improving dust removal efficiency. By comparing the speed at the center line of the plate and near the plate, it is obvious that the speed of model B decreases significantly, and as the number of discharge electrodes increases, the speed decreases more obviously. At the same time, when the dust collection efficiency of the two models was compared, it was found that the working efficiency of the B model has been significantly improved, among which the B3 model has the best dust collection effect.

New Charged Interfaces for Energy Conversion and Catalysis

Charged interfaces are key areas for charge transfer and chemical reactions. Studying these interfaces at the microscopic level, especially in constructing and characterizing specific structures, understanding charge transfer, and managing chemical reactions, is crucial but challenging. Our work focuses on three innovative interface structures: solid/solid triboelectric, liquid/gas electrified, and solid/ultrathin heterojunction interfaces. We have achieved significant insights into the charge transfer mechanisms within these electrified systems and effectively controlled catalytic reactions at these interfaces.Key findings include: Development of new concepts for contact electrification and electrostatic-induced coupling at solid/solid interfaces, leading to novel applications in energy conversion and catalysis. We introduced the concept of mechanical-electric-catalytic reactions based on triboelectric interfaces and achieved direct synthesis of hydrogen peroxide through friction-catalysis under normal conditions.Effective control of reaction kinetics and selectivity in charged microdroplet liquid/gas electrified interfaces by adjusting parameters like droplet evaporation rates and electric field characteristics. This approach led to efficient production of hydrogen peroxide and selective conversion of carbon dioxide.Precise atomic-level construction and sub-nanometer characterization of solid/ultrathin heterojunction interfaces, exemplified by gold/graphene interfaces. This included the development of a gold/ultrathin palladium/single-layer ruthenium structure, enabling in-depth study of hydroxylation reactions and the influence of palladium interlayers on ruthenium's catalytic efficiency.

Space Charge and Electric Field Characteristics in XLPE-Insulated Extrusion Molded Joint for HVDC Submarine Cables: Experiment and Simulation

Space Charge and Electric Field Characteristics in XLPE-Insulated Extrusion Molded Joint for HVDC Submarine Cables: Experiment and Simulation

Simulation Modeling of the Characteristics of the Primary Electric Field at the Boundaries of a Liquid Metal Object Treated by Passing an Electric Current

Simulation Modeling of the Characteristics of the Primary Electric Field at the Boundaries of a Liquid Metal Object Treated by Passing an Electric Current

Modeling and Sensitivity Estimation of a Dual Cavity Source Pocket-Based Charge Plasma Tunneling FET for Label-Free Biological Molecule Detection

A dual-source cavity charge plasma tunneling FET (DSC-SP-CPTFET) with SiGe Pocket is proposed, and its effectiveness as a biological sensor for label-free detection is explored. The fabrication complexity and cost have been reduced by using the charge-plasma concept. For improved sensing, an etched nanocavity is added to the upper and lower of the source metal section. The high-k (HfO2) gate oxide and minimal energy gap (Si0.6Ge0.4) alloy with a 40% mole fraction improve the current sensitivity by enhancing the drain current gradient. The sensitivity of the suggested biological sensor is assessed here for several neutral biological molecules, such as Gelatin, Keratin, Biotin, and 3-Aminopropyl-Triethoxysilane (APTES). Deoxyribonucleic acid (DNA), a charged biological molecule, is also considered with varying positive and negative charge densities. The suggested biological sensor shows a (SIDS)max of 2.21 × 1010 and a Sratio of 3.11 × 109 for biological molecules with higher dielectric constant at room temperature. Different electrostatic performances are estimated in the ON state, including energy band, electron (e-) BTBT rate, electrical field, and IDS-VGS characteristics. In addition, the proposed biological sensor provides a much superior drain current sensitivity (SIDS), current ratio sensitivity (Sratio), and average SS sensitivity (SSS) performance in the presence of both charged and neutral biological molecules.

Analysis of Electric Breakup Characteristics of Emulsion Droplets Based on Dissipative Particle Dynamics Method

Crude oil desalination and dehydration are necessary for storage, transportation, and processing procedures. However, the behaviour of fine emulsion droplets under an electric field has always been questioned. This paper modified the dissipative particle dynamics method (DPD) to study the deformation process of fine emulsion droplets under a high-strength electric field. Compared with the literature data, the reliability of the DPD method is confirmed. The influence of the crude oil properties and the electric field characteristics on the behaviour of the emulsion droplet was analysed, and the effect factors included electric field intensity, electric field frequency, emulsion droplet size, centre distance ratio, conservative force intensity, dissipative strength, and crude oil density. The relationship between critical electric field intensity and emulsion droplet deformation was formulated based on the simulational dates.

Constructing interfacial chemical interaction of dual-carbon protected cobalt diselenide anode for sodium storage

Transition metal selenides are attracting enormous attention due to their high theoretical capacity and appropriate working potential for sodium storage, while their intrinsic low electronic conductivity and large volume expansion during the cycling processes inevitably result in inadequate rate performance and inferior cycling stability. Herein, cobalt diselenide-based hollow sugarloaf-like self-supporting fiber membranes with strong interfacial chemical (Co-C) bonds have been reported for sodium-ion batteries (SIBs) via the dual-carbon protection strategy. Based on X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) combined with density functional theory (DFT), A built-in electric field is generated at the interface between CoSe2/C and CNFs, which provides a strong driving force for electron transfer and ion migration, making the optimal CoSe2/C−0.3@CNFs anode over 67.8 % of capacity retention from 0.1 to 5 A/g and maintained about 269.5 mAh/g of discharge capacity at 5 A/g. The strong interfacial Co-C bonds in CoSe2/C@CNFs enhance the interfacial affinity between CoSe2/C and CNFs, making it easier for CoSe2/C to trap sodium ions and effectively resist the volume expansion during cycling, thus showing excellent cyclic stability with a reversible capacity of 247.6 mA h g−1 at 1.0 A/g after 2600 cycles. The sodium storage mechanism of CoSe2/C−0.3@CNFs electrode in SIBs is systematically analyzed via in-situ XRD and in-situ Raman spectra. This study provides an effective approach to constructing heterostructured composites with strong chemical bonds and built-in electric field characteristics for high-rate capability and long-cycle stability SIBs. Moreover, the sodium ion diffusion kinetics in the CoSe2/C−0.3@CNFs anode is also revealed.

Development of a MATLAB‐based graphical user interface to illustrate Coulomb's law and Gauss's law

AbstractCoulomb's law and Gauss's law are two fundamental laws in electrostatics that involve electric charges and electric fields. These concepts that are not visible physically in real life can be challenging for students to understand, especially when it involves complex charge distributions. This paper presents a MATLAB‐based graphical user interface (GUI) to visualise the concept of Coulomb's law and Gauss's law as well as a serious snake game to reinforce users' knowledge. This MATLAB GUI features a diverse range of 3‐dimensional (3D) visualisations illustrating electric field attributes such as electric force, charge distribution and electric flux. These visualisations dynamically adapt to user‐defined parameters, offering a rich and varied exploration of the electric field's characteristics without confining the scope to a specific count of models. In Coulomb's law section, the GUI plots the electric forces in 3‐D for dipole, three‐point charges, and unlimited charge. The Gauss's law section consists of windows for illustration of the fundamentals of Gauss's law for the electric field, and the illustration for the application of Gauss's law in finding the electric field for a point charge, infinite line charge and infinite plane charge. The serious snake game developed in this work allows students to engage in quizzes related to Coulomb's law and Gauss's law to serve as a tool for reinforcing their learning outcomes. The MATLAB‐based GUI was chosen as the platform due to its excellent visualisation capabilities, ease of programming and capability to act as a powerful tool to enhance the learning of Coulomb's law and Gauss's law for students.

Enhancing photoelectrochemical properties of α-Fe2O3 using Zr-doped HfO2 ferroelectric nanoparticles

Hematite (α-Fe2O3) as a semiconductor photoanode for photoelectrochemical (PEC) water splitting is a promising candidate material. However, its PEC performance is limited by the slow charge transfer kinetics at the α-Fe2O3/electrolyte interface. Ferroelectric materials can be used as a tool for carrier separation in photoelectrochemical water splitting due to their spontaneous polarization electric field characteristics. Here, we deposited Hf0.5Zr0.5O2 (HZO) ferroelectric nanoparticles on the surface of α-Fe2O3 and use the spontaneous polarization field of ferroelectric HZO to promote the separation of photogenerated carriers, promote the charge transfer from α-Fe2O3 to the electrolyte, and enhance the PEC of hematite. After depositing the HZO nanoparticles, the photogenerated holes are efficiently extracted from α-Fe2O3 and then directed into the electrolyte to participate in water oxidation reaction at α-Fe2O3/HZO interfaces, which enhanced the charge separation efficiency by 58 % compared to that of pure α-Fe2O3. Consequently, the α-Fe2O3/HZO photoanode exhibits a 65 % boost in photocurrent density, reaching up to 0.28 mA cm−2 at 1.23 V versus the reversible hydrogen electrode (VRHE) compared to that of pure α-Fe2O3. This study introduces a method to engineer the photoanode/ferroelectric interface, enhancing carrier separation and thereby optimizing PEC water splitting performance.

Experimental and Simulation Studies on Stable Polarity Reversal in Aged HVDC Mass-Impregnated Cables

Mass-impregnated (MI) cables have been used for many years as cables in high-voltage direct current (HVDC) systems. In line commutated converter (LCC) HVDC systems, polarity reversal for power flow control can induce significant electrical stress on MI cables. Furthermore, the mass oil and kraft paper comprising the impregnated insulation have significantly different coefficients of thermal expansion. Load fluctuations in the cable lead to expansion and contraction of the mass, creating pressure within the insulation and causing redistribution of the impregnant. During this process, shrinkage cavities can form within the butt gaps. Since the dielectric strength of the cavities is lower than that of the surrounding impregnation, cavitation phenomena in impregnated paper insulation are considered a factor in degrading insulation performance. Consequently, this study analyzes the electrical conductivity of thermally aged materials and investigates the transient electric field characteristics within the cable. Additionally, it closely analyzes the formation and dissolution of cavities in MI cables during polarity reversal based on a numerical model of pressure behavior in porous media. The conductivity of the impregnated paper indicates that it has excellent resistance to thermal degradation. Simulation results for various load conditions highlight that the interval of load-off time and the magnitude of internal pressure significantly influence the cavitation phenomenon. Lastly, the study proposes stable system operation methods to prevent cavitation in MI cables.

Upgraded Low-Frequency 3D Lightning Mapping System in North China and Observations on Lightning Initiation Processes

The three-dimensional (3D) low-frequency lightning mapping system (LF-LMS) in north China has been updated. The lightning electric field derivative (dE/dt) sensor and continuous acquisition mode has been newly designed to ensure a capability of entire lightning processes detection, especially weak discharges during lightning the initiation process. The twice cross-correlation delay estimation and the grid iteration nested optimization location algorithm are used to realize the 3D location of the discharge channel, and the location resolution and calculation speed are balanced consequently. The location results of the rocket-triggered lightning demonstrated that the system achieved a high-resolution mapping of lightning discharge channels, which coincided well with the optical images. The horizontal and vertical location error for rocket triggered lightning was less than 40 m in both horizontal and vertical. Intracloud (IC) lightning flashes were observed to be initiated by three different discharge processes, initial breakdown pulse (IBP), narrow bipolar event (NBE), and initial E-change (IEC). The corresponding initial height was 10.5 km, 6.9 km, and 9.2 km, respectively. The upward negative leader was initially located, followed by scatter radiation sources and negative recoil leaders in the lower negative charge region for all cases. The electric field characteristics of the IEC and subsequent IBPs indicated that they are different discharge processes with the same current direction. The IEC process might correspond to the discharge process with continuous current and less noticeable current changes.

Photodetector array for measuring the spatial–temporal distribution characteristics of electric field in oil–pressboard insulation based on the Kerr electro‐optic effect

AbstractAccurate measurement and effective analysis of the space electric field and charge characteristics within the oil–pressboard insulation structure of converter transformer are essential for achieving precise insulation structure design. Presently, most electric field measurement methods relying on the Kerr electro‐optical effect are limited to single‐point measurements. Given the complexity of converter transformer insulation structures, including their large scale and the use of various materials, existing technologies and findings struggle to provide comprehensive electric field observations within the oil–pressboard region. After leveraging the Kerr electro‐optic effect, a high‐precision 32‐unit photodetector array has been developed to achieve regional measurements of spatial‐temporal electric field in oil–pressboard insulation. The array boasts a measurement spatial resolution of 1.4 mm2 and a sensitivity of 0.15 kV/mm, ensuring measurement accuracy exceeding 96.50%. Through practical measurements of the spatial electric field distribution within the oil–pressboard insulation under direct current voltage, the non‐uniform distribution of the electric field is effectively captured in oil. Notably, the maximum deviation in field strength at different positions within the transformer oil can reach 18.5%. Moreover, as the applied voltage increases, the unevenness coefficient of the field strength gradually rises, peaking at 1.19, which signifies a progressive expansion in the area affected by electric field distortion. By conducting tests to assess the dispersion of volume resistivity in samples from various positions within large sheets of pressboard, the variation in volume resistivity of materials is posited as one of the contributing factors to the non‐uniform distribution of electric field within the oil. The detailed accomplishments aim to provide essential technical and theoretical support for optimising insulation structure design of converter transformers.