A5033519367- High voltage insulation and dielectric phenomena
- Electrical Fault Detection and Protection
- ZnO doping and properties
- Dielectric materials and actuators
- Electrostatic Discharge in Electronics
- Lightning and Electromagnetic Phenomena
- Thin-Film Transistor Technologies
- Gas Sensing Nanomaterials and Sensors
- Thermal Analysis in Power Transmission
- Power Transformer Diagnostics and Insulation
- High-Voltage Power Transmission Systems
- Advanced Sensor and Energy Harvesting Materials
- Ga2O3 and related materials
- Power Systems Fault Detection
- Integrated Circuits and Semiconductor Failure Analysis
- Aerosol Filtration and Electrostatic Precipitation
- Electromagnetic Compatibility and Noise Suppression
- Engineering and Test Systems
- Concrete Corrosion and Durability
- Structural Health Monitoring Techniques
- Magneto-Optical Properties and Applications
- Plant-Microbe Interactions and Immunity
- Legume Nitrogen Fixing Symbiosis
- Ultrasonics and Acoustic Wave Propagation
- Air Traffic Management and Optimization
Sichuan University
2020-2025
Southern University of Science and Technology
2024
Lanzhou Jiaotong University
2024
Tsinghua University
2016-2022
Rensselaer Polytechnic Institute
2016
Grafting modification is an effective method to enhance the electrical characteristics of polymeric materials by establishing deep traps that prevent carriers from being injected and transmitted. However, grafted polymers for insulation suffer large leakage current at elevated temperatures, limiting their application in harsh environments. We report itaconic anhydride polypropylene synthesized solution grafting preserves excellent insulating properties up 120 °C. It demonstrated restrains...
Polypropylene has been regarded as a potential recyclable insulation material for HVDC cable, which is beneficial to improve the working temperature and transmission capacity of cables. However, electrical properties polymeric materials exhibit apparent dependent characteristics. Temperature influences generation migration charge carriers, thereby affecting properties. This paper focuses on polypropylene nanocomposites at different temperatures, including volume resistivity, space DC...
Partial discharge (PD) measurements under repetitive impulse voltages are critical for the qualification of inverter-fed motor insulation systems. Severe electromagnetic interference due to high frequency switching from power electronic devices can cause traditional PD detection techniques sinusoidal voltage unfeasible. This article presents design an Archimedes spiral antenna that work effectively fast rise time voltages. The structure is optimized by a media superstrate with dielectric...
This paper proposes a cable defect location method based on the power spectral density (PSD) to improve accuracy of existing frequency domain reflection (FDR) method. The principle proposed is that empirical mode decomposition (EMD) used decompose envelope coefficient into intrinsic function (IMF) each insulation point and real part IMF signal windowed. Then, according characteristics random with definite auto-correlation function, PSD analysis performed limited power. In theory, spectrum...
A frequency domain reflection (FDR) method has been widely used to locate cable defects. Generally, the performance of FDR can be enhanced by extending sweeping range signal. However, with increase in signal frequency, misdiagnosis easily occur owing attenuation and noise. Thus, this paper's authors propose upper (UF) selection improve accuracy defect location. First, cable's three-dimensional location spectrum, including spatial information, is obtained at a wide based on short-time Fourier...
Drought is one of the most serious abiotic stresses, and emerging evidence suggest plant microbiome affects drought tolerance. However, there a lack genetic regarding whether how plants orchestrate dynamic assembly upon drought. By utilizing mutants with enhanced or decreased root hair densities, we find that regulators also affect induced changes. Rhizobiaceae key biomarker taxa affected by related mutants. We isolated sequenced 1479 associated microbes, confirmed several Rhizobium strains...
Electrostatic discharge is a fatal threat to variety of electronic products. Here we report on polymer nanocomposite composed dielectric embedded with aligned core–shell structured nanowires for highly efficient distributed electrostatic protection. The capable self-adaptive charge release, stemming from the nonlinear interface built in Bi/Co oxide coated ZnO that leads "hand-in-hand" double-Schottky barrier. ultralow filler concentration (e.g., 0.5 vol %) endows low permittivity (close...
Due to the spurious peaks caused by multi-reflection and randomness of cable transfer function, frequency domain reflection (FDR) method based on Fourier transform (FT) is inaccurate, even resulting in misjudging soft faults cable. Thus, this paper, a sweep location multiple signal classification (MUSIC) pseudospectrum proposed accurately diagnose locate faults. The idea extend function into an array estimate MUSIC-pseudospectrum which can analysis uncertain signals deterministic functions....
Condition assessment is significant to the maintenance management of high-voltage (HV) cross-linked polyethylene (XLPE) power cables. This article presents a condition method for corrugated aluminum sheathed cables based on evolved gas analysis (EGA). First, simultaneous thermogravimetric (TG) and mass spectrometric analyses pyrolysis each cable material were conducted characterize generation caused by thermal faults. Simulated experiments designed investigate electrical The results show...
The potential recyclable thermoplastic materials represent the future trend of HVDC cable insulation material to replace crosslinked polyethylene (XLPE). Polypropylene block copolymer (PPB) and polypropylene random (PPR) with different weight-averaged molecular weight (Mw) were used investigate influence structure on their properties. morphology, thermal, mechanical electrical properties PP copolymers comprehensively studied. results show that PPB has good thermal properties, but its poor...
Silicone grease (SG) is used for lubrication during cable accessory installation and can penetrate into the silicone rubber (SiR), leading to properties deterioration of SiR. In this study, effects SG on breakdown characteristics cross-linked polyethylene (XLPE)–SiR interface are investigated. First, variation XLPE–SiR voltage with coating time experimentally explored. The significantly increases after applied, remains stable times up approximately 144 h then rapidly decreases; minimum lower...
The steady-state electrical conduction current for single and multilayer polyimide (PI) nanocomposite films was observed at the low high electric field different temperatures. Experimental data were fitted to models investigate dominant mechanism in these films. In most films, space charge limited (SCLC) Poole–Frenkel displayed conduction. At a field, ohmic replaced by current–voltage dependency. Higher lower temperature, but it declined higher temperature. PI showed huge reduction fields...
This work investigates the electrical tree growth of epoxy resins. Repetitive bipolar square wave voltage is applied to resins and different parameters rise time, frequency, duty cycle are studied. The frequency range repetitive ranges from 50 Hz 20 kHz, time 70 ns 620 ns, 5 90%. results reveal that initiation more rapid under influence high having a shorter time. Moreover, faster impact with greater than 10%. mainly affects process trees. In comparison, primary on its attributed applied.
This paper presents the surface modification and charge transportation mechanism of thin polyimide films. Here, we demonstrate that these films, by using fluorine gas-phase, improves charges mitigation and, thereafter, suppress space charges. The experimental results indicate thermal step current for coated films reduce significantly in comparison to pure layer coating helps release charge, injection from electrode, provide hindrance penetrate into bulk higher degree disappearing growth.
The phase of the reflected wave at defect can characterize change type defect. frequency domain reflection (FDR) method be used to locate cable defects based on from waves, but cannot determine sign a wave. In this article, judgment for is proposed analyze First, fast Fourier transform (FFT) interpolation algorithm Hanning self-convolution window Then, deviations are corrected eliminate effect limited starting FDR method. Also, frequency-dependent velocity revised according location. value...
Microvaristor ceramics blended with insulation polymers can function as nonlinear dielectrics, which possess self-adaptive electrical parameters varying the applied field. Broadening switching (electric) field of dielectrics for their applications in various apparatus and voltage class is an important issue. This paper prepared ZnO microvaristor different grain size through controlling sintering temperature, well ceramic/polymer composites (MCPC) filler concentration, diameter, size. The V-I...
Partial discharge (PD) test has been widely used in condition assessment for power cables. However, extinguish phenomenon occurred PD detection hinders the effective of potential defects cable accessories. For this reason, a novel method based on thermal excitation is proposed article to eliminate and detect earlier stage. First, physical processes activity reasons extinguishing are introduced. Then, principle mechanism described analyzed respectively, that by external heating break dynamic...