A5014075490- High voltage insulation and dielectric phenomena
- Power Transformer Diagnostics and Insulation
- Lightning and Electromagnetic Phenomena
- Aerosol Filtration and Electrostatic Precipitation
- Advanced Sensor and Energy Harvesting Materials
- Thermal Analysis in Power Transmission
- Dielectric materials and actuators
- Plasma Diagnostics and Applications
- 3D IC and TSV technologies
- Electrical Fault Detection and Protection
- Electrostatic Discharge in Electronics
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Surface Polishing Techniques
- Plasma Applications and Diagnostics
- Semiconductor materials and devices
- Surface Modification and Superhydrophobicity
- Electronic Packaging and Soldering Technologies
- Nanofabrication and Lithography Techniques
- Electrohydrodynamics and Fluid Dynamics
- Vacuum and Plasma Arcs
- Polymer Nanocomposites and Properties
- Neural Networks and Applications
- High-Voltage Power Transmission Systems
- Chaos control and synchronization
- Advancements in Photolithography Techniques
Hefei University of Technology
2021-2023
Xi'an Jiaotong University
2005-2021
State Key Laboratory of Electrical Insulation and Power Equipment
2016
Cisco Systems (United States)
2010-2012
The accumulated charges on the insulator surface become a key factor to incur flashover. charge accumulation process is closely related condition. This research investigates effects of roughness behavior and flashover performance alumina-filled epoxy resin spacers in SF6/N2 mixtures under DC voltage. prepared with only half subjected rough treatment. are distributed two regions. Considerable homo-charges located near high voltage (HV) electrode few hetero-charges grounded (GND) (region I)....
The construction of the future energy structure China under 2050 carbon-neutral vision requires compact direct current (DC) gas-insulation equipment as important nodes and solutions to support electric power transmission distribution long-distance large-capacity. This paper reviews China's 10-year progress in DC gas-insulated equipment. Important progresses basic research industry perspective are presented, with related scientific issues technical bottlenecks being discussed. worldwide...
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....
Interfaces between different materials, for instance, electrode–dielectrics and vacuum/air/SF6-insulators oilpaper, are universal in high-voltage insulation systems. Targeted tailoring of the interfacial properties, e.g. chemical structures, micro-/nanoscale morphology, charge injection barrier, trap states, surface conductivity, is thought to be an effective approach improve properties such as breakdown flashover strength, corona/tracking resistance, wettability. In this article, authors...
An investigation is conducted regarding the influence of surface roughness on flashover strength an insulator in vacuum. A series experiments first presented, showing relationship between and voltage, combined with measurement potential distribution. It found that charging a roughened dielectric suppressed remarkably; also voltage threshold depicts rise-and-fall trend increasing, exhibiting summit at certain value. In addition, optical observation implemented to draw parallel electron...
In this study, we used simulation technique to analyze the thermal behaviors and investigate issues of a designed system in package (SiP) for network application that based on three dimensional integrated circuit (3D IC) structure. The 3D IC SiP has an interposer which with regularly embedded through-silicon vias (TSVs); there are one CPU chip two DRAM chips planted top side bottom interposer, respectively. is bonded BT substrate; substrate PCB; metallic heat spreader placed glued chip's...
Partial discharge (PD) measurement and interpretation have become a powerful tool for condition monitoring failure risk assessment of high voltage power equipment insulation. The occurrence multiple sources affects accuracy. This paper presents PD signal separation algorithm using cumulative energy (CE) function parameters clustering technique. waveform signals are acquired by digital detection instruments with sampling rate. Cumulative functions in time domain (TCE) frequency (FCE)...
Surface charge accumulation on insulator surface can have great influence flashover performance. An experimental system is established to investigate and decay characteristics of Al2O3-filled epoxy resin insulators in 0.1 MPa SF6 under DC voltages. potential recorded by a Kelvin vibrating probe connected an electrostatic voltmeter. By pre-depositing charges surface, the performance studied. The results reveal that distribution appearance combined effect electrode injection, back discharge...
Surface flashover properties of alumina/epoxy spacers, involving a surface charge accumulation process, are critical for the safe and reliable operation high-voltage direct-current (HVDC) gas-insulated transmission line (GIL). This study reports charging behavior performance spacers with different conductivity graded coating (SCGC) schemes in SF6/N2 mixtures under DC stress. Four kinds SCGC schemes, i.e. localized near high voltage (HV-coating), grounded electrode (GND-coating), at middle...
Surface charges accumulated on solid insulating materials in electrical apparatuses and electronic devices could distort the initial electric field severely damage insulation performance. Accurate transient surface charge measurement is critical to determine mechanisms of transport flashover occurrence, estimate strength under high voltage. The technique based Pockels electro-optic effect considered as only approach for 2-D dynamic distribution behaviour so far, it has good capability avoid...
Abstract Surface charge accumulation is the potential criminal for surface insulation failure on spacers under direct current (DC) voltages. The existence of thermal gradient posing difficulty regulation. This study proposes a temperature‐dependent adaptive conductivity coating technique surppressing electro‐thermal coupling field. A two‐dimensional axis‐symmetrical simulation model regrading computation established. effects gradients and electric field distribution are investigated. results...
The backward discharge induced by residual charge has attracted considerable attention, but the complex mechanism requires further investigation. This article analyzes surface and accumulation characteristics in atmospheric air under a positive impulse. photographic figure method, dust electrostatic probe method are employed, allowing distribution to be quantitatively determined. One main forward is observed at impulse front several subsequent discharges tail. propagation length of streamer...
Surface charge accumulation on spacer is an important factor to cause surface flashover. An experimental set‐up established measure potential over a truncated cone‐type under DC voltage in SF 6 gas at atmospheric pressure using Kelvin vibrating electrostatic probe. The density calibrated based multipoint measurement technique, which takes the influence of probe into account. results show that distribution patterns can be divided three classes including centrosymmetric distribution, spot‐like...
The vacuum discharge along the dielectric surface, also called surface flashover, brings significant damages to vacuum-solid insulation system. Here authors implement shape-flexible, complex groove microstructures on mitigate initiation of flashover. A particle-in-cell simulation is employed reveal real-time development considering blockage multipactor propagation as well space field distortion in presence specific microstructures. Electron trajectories within barriers are theoretically...
In this study, a simulation model is established to study the effect of surface conductivity on accumulation charge. The shows that hetero-charges increase areas away from high voltage electrode and electric field distribution along becomes more uniform with increased conductivity. dominant charging mechanism changes conduction through bulk insulation When ranges 1×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-15</sup> 5×10...
Ultra‐high‐frequency (UHF) method is regarded as an effective approach for partial discharge (PD) detection in gas insulated substation (GIS). The feature parameters representing UHF signal characteristics can be extracted from its waveform, and applied to PD source classification mixed signals separation. In this study, extraction algorithm based on cumulative energy (CE) technique proposed. CE functions time domain (TCE) frequency (FCE) are calculated waveforms their fast Fourier transform...
Partial discharge (PD) measurement is an effective tool for insulation condition assessment of high-voltage power equipment. The occurrence multiple PD sources causes great difficulty on pattern recognition and failure risk assessment. This paper presents a self-adaptive separation algorithm based optimized feature extraction cumulative energy (CE) function. CE functions in time domain (TCE) frequency (FCE) are calculated from waveforms their FFT spectrums, respectively. By using oblique...
Abstract To investigate how the multiphase structures affect electrical conductivity in semi‐crystalline polymer composites, herein, an accurate content calculation method is proposed and verified, which combines amorphous phase information broadband dielectric spectroscopy crystalline differential scanning calorimetry. Taken aluminium hydroxide (ATH) filled silicone rubber as example, it found that rigid fraction (RAF) corresponding to chains constrained by crystals (RAF cry ) not linearly...
When metal particle is attached on spacer surface, it will distort surface electric field and may reduce insulation level. Therefore, important to research the relationship between attachment flashover property. In this study, effect of materials performance alumina-filled epoxy resin spacers in SF6/N2 mixtures investigated. Three kinds including copper, iron aluminum are considered. The results reveal that, at low gas pressure or field, material has no obvious voltage. At high voltage...
In high-voltage power equipment, insulation defects are probably generated during the production, assembly, and operation processes, which degrade materials even cause failure under electrical stresses. As a result, various detection diagnosis methods for status have been developed to discover potential in but extra testing devices usually required. Insulation with special stimulus–response performance, as an example, luminescence stimulation of intensified electric field or temperature...