Solid insulators applying functionally graded material (d-FGM) have spatially non-uniform dielectric properties. The d-FGM insulator is effective on insulation performance improvement without complicating the structure; however, fabrication of such remains a challenge. To investigate feasibility 3D printing technology d-FGM, we designed and fabricated conductivity tested its surface flashover characteristics. First, modified genetic algorithm employed to design distribution in insulator....

Dielectrics with functionally graded material (d-FGM), which have spatially nonuniform dielectric properties, is effective to improve the insulation performance without complicating structure. In application of d-FGM, searching optimal distribution properties (permittivity or conductivity) most important goal, however difficult for conventional design approaches. this paper, topology optimization technique introduced a truncated cone insulator permittivity FGM, relieve local electric field...

Abstract Vacuum‐dielectric interface is the most vulnerable part of vacuum insulation systems where surface electrical breakdown prone to happen, hence severely restricts development advanced electro‐vacuum devices with large capacity and its miniaturisation. Generally, a direct effective way improve alleviate initiation multipactor phenomena. Inspired by this approach, authors report 3D‐printed structure designed millimetre‐scale cavity covered periodic through‐pore array via...

Epoxy/alumina composite materials are widely used in support insulators air/SF6 switchgear. However, epoxy resin is difficult to be recycled or repro- cessed because of its cross-linked structure. With the worldwide promotion net-zero strategy, it necess- ary investigate suitable replacement for resin. For this purpose, article investigates applicability several thermoplastic alternatives and selects an optimal material future research. The first study comparison basic electrical mechanical...

The presence of a macroscopic interface between ceramic insulators and vacuum inevitably leads to multipactor under high electric fields, which is significant threat various electronic electrical devices, as it typically regarded precursor breakdown. In this study, we report strategy using functionally graded lattice structures (FGLS) manipulate the surface. First, particle-in-cell simulations were conducted study secondary electron avalanche process. Simulation results indicated that...

High-voltage and high-power devices are indispensable in spacecraft for outer space explorations, whose operations require aerospace materials with adequate vacuum surface insulation performance. Despite persistent attempts to fabricate such materials, current efforts restricted trial-and-error methods a universal design guideline is missing. The present work proposes improve the by tailoring trap state density energy level of metal oxides varied bandgaps, using coating on polyimide (PI)...

The atmospheric pressure pulsed microwave He plasma jet has the advantages of high electron density and abundant active particles, but its shrinking on discharge electrode morphology limits application range. In order to modulate a with longer plume study ionization development characteristics, we constructed dual-channel coaxial device. air were, respectively, injected into inner outer gas channels resonator generate double-layer plume. It is observed that bifurcation stratified will occur...

A facile method using a nanocomposite coating is proposed to suppress surface charge accumulation and enhance the breakdown strength of polymeric insulating materials like epoxy resin by covering thin modified alumina flake/UV curable coating.

Dielectrically graded insulation (DGI) with spatially inhomogeneous dielectric parameter distribution can provide extraordinary performance for high-voltage power equipment. The most crucial objective in the application of DGI is to identify optimal parameters. However, calculation efficiency and electric field optimization results existing methods are poor under complex structures. Also, loss calculated by these relatively large. In this work, an efficient method was developed. First, a...

Abstract Spacecraft charging and electrostatic discharging (ESD) are prone to occur in harsh space environments. In particular, the case of coupling strong electromagnetic field (EMF), ESD damages may at a low potential, posing serious threat on-orbit spacecraft missions. To investigate mechanism pertinent suppression method for vacuum surface discharge induced by EMF, specially-designed platform EMF-induced was set up. Surface structures with various spatial scales were created separately...

Abstract The flashover in vacuum is a rapid interfacial discharge across the insulator surface when subjected to high applied voltage. Here theoretical model covering above‐surface processes introduced. calculates threshold vacuum, with revised secondary electron emission avalanche theory and improved desorbed neutral transport model. serves as first part of an integrated model, aiming for consistent treatment both subsurface during entire development. obtained by combining pressure at given...

Dielectrically graded insulation (DGI) serving as an embodiment of functionally materials in electrical field displays extraordinary strength compared with conventional uniform composite materials. In recent years, the design and fabrication DGI toward industrial applications have become urgent issues. Here, we reported a construction strategy for gas-insulated equipment. A topology optimization method was applied to optimize electric ( <inline-formula...

Due to the increase in voltage levels and line lengths of power cables, commonly used alternating current resonance (ACR) is challenging meet growth rate capacitance ultrahigh-voltage cables for on-site partial discharge (PD) tests. PD research on power–frequency-like voltages, such as damped (DAC) voltage, very low-frequency sine wave (VLF-Sine) cosine rectangular (VLF-CR) has important engineering value evaluating cable insulation conditions. In this article, a test measurement system...

Surface flashover across insulator in vacuum is a destructive plasma discharge which undermines the behaviors of range applications electrical engineering, particle physics, space etc. This phenomenon widely modeled by particle-in-cell (PIC) simulation, here continuum and kinetic simulation method first proposed implemented as an alternative solution for modeling, aiming prevention unfavorable noises PIC models. The 1D2V (one dimension space, two dimensions velocity) model constructed....

Surface hydroxylation of crude Al2O3 (c-Al2O3) nanoparticles by H2O2 was conducted to tailor the electrical properties UV-cured resin. The hydroxyl groups on particles were designed establish hydrogen bonding between and carboxyl groups, which favors enhancement interfacial strength fillers resin matrix. effect investigated. Owing improved strength, it can be conjectured that a larger volume interaction zone exists in resin/hydroxylated (UV/h-Al2O3) composites. As consequence, number deeper...

To prepare high-permittivity composite materials for dielectrically functional gradient (d-FGMs) by the stereolithographic 3D-printing technique, three ceramic powders (i.e., alumina, barium titanate, and strontium titanate) are selected as fillers a UV-curable resin matrix. The viscosity UV curing depth of uncured slurry tested feasibility 3D printing. Comprehensive electrical properties, including volume resistivity, permittivity, dielectric loss, breakdown strength cured composites...

Anhydride-cured epoxy resin (ACER) has excellent performance and is commonly employed as insulation material in power equipment. However, it difficult to decompose recycle owing its 3-D network structure, conventional waste disposal processes would damage the environment. It therefore necessary degrade or even by other techniques. In this article, chemical degradation of ACER alcoholysis reaction realized under mild conditions within a short time, degraded (DER) utilized replace part...

3D printing technology is a rapid prototyping which in the process of fast development. It has advantages no mold requirement, high precision and shape controllability. To apply field electric engineering, it necessary to understand insulating properties microstructure parts. In this paper, several commonly used techniques are taken into consideration, including stereolithography apparatus (SLA), fused deposition modeling (FDM), selective laser sintering (SLS). Representative materials for...