Article
Materials Science, Multidisciplinary
Yiwen Shi, Xiangrong Chen, Fan-Bo Meng, Zelin Hong, Muhammad Awais, Ashish Paramane
Summary: This study investigates the influence of three different voltage stabilizers on the insulation properties of cross-linked polyethylene (XLPE). The results show that the addition of the voltage stabilizers enhances the DC resistivity and DC breakdown strength of the XLPE, which also inhibits the accumulation of space charges in the XLPE.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Polymer Science
Jun-Guo Gao, Hong-Shuo Liu, Ting-Tai Lee, Uwe Schachtely, Hitoshi Kobayashi, Li-Li Li
Summary: This paper investigates the impact mechanism of nanosized hydrophilic and hydrophobic fumed titania on the electrical properties of polypropylene. The results show that hydrophilic TiO2 decreases the space charge suppression ability of the nanocomposite, while hydrophobic TiO2 improves the AC/DC breakdown strength.
Article
Engineering, Electrical & Electronic
Hyungjin Yoon, George Chen, Ian L. Hosier
Summary: Mineral oil is commonly used as a dielectric liquid in HVDC converter transformers due to its excellent electrical insulation and cooling properties. However, the low biodegradability and high fire risk of mineral oil have sparked interest in natural ester oil as a potential alternative. This article investigates the impact of thermal aging on the space charge characteristics of natural ester oil-impregnated paper compared to mineral oil-impregnated paper. The results show that although natural ester oil leads to increased charge accumulation, it exhibits a higher dc breakdown voltage compared to mineral oil.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Construction & Building Technology
Marcio Goncalves, Nuno Simoes, Catarina Serra, Ines Flores-Colen
Summary: The study proposes a novel laboratory test method to evaluate the hygrothermal performance of an external vacuum-insulation composite system. The system was found to be resistant to hygrothermal cycles but sensitive to solar radiation conditions and finishing coat colors, potentially leading to anomalies such as microcracking.
ENERGY AND BUILDINGS
(2022)
Article
Engineering, Electrical & Electronic
Yang Wu, Kai Wu, Chuanhui Cheng, Rui Su, Zepeng Lv, Shuangzan Ren, Jingfeng Wu, Hao Wu
Summary: This paper proposes a method of distinguishing the contributions of ionized and injected charges to the charge transport in oil immersed paper in triple-layer and double-layer samples. By comparing the accumulated charge density in double-layer and triple-layer samples, it is found that ionization charges mainly contribute to interface charge under low electric field, while injected charges play a more important role at higher electric field.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Engineering, Electrical & Electronic
Dongxin He, Haoxin Guo, Wenjie Gong, Zhe Xu, Qingquan Li, Shijie Xie
Summary: In this study, a test pulse matching circuit was developed to accurately match the test pulse with the polarity reversal polarization voltage and perform a multi-point rapid test of the space charge transient characteristics during polarity reversal. The influence of polarity reversal time on the charge residence characteristics of oil-paper insulation was compared and analyzed. The study of the charge residence characteristics and the dynamic charge behavior during the polarity inversion process has important guiding significance for clarifying the deterioration mechanism of the converter transformer oil-paper insulation under polarity-reversal electric field.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Engineering, Electrical & Electronic
Fan Yang, Kai Zhou, Shakeel Akram, Muhammad Tariq Nazir
Summary: This paper introduces a new method for testing PDC in high-voltage wire, which can efficiently eliminate interference and accurately measure PDC in an industrial environment. The method uses an equipotential picoammeter connected in series with the high-voltage wire, and a device with automatic switching function.
Article
Energy & Fuels
Zhenpeng Zhang, You Wu, Chao Fu, Shaoxin Meng, Chao Peng, Zhonglei Li, Boxue Du
Summary: This study focused on the effect of pre-crosslinking on the electrical properties of XLPE insulation for HVDC cables. The results show that pre-crosslinking leads to increased electric field distortion, space charge accumulation, and decreased DC breakdown strength in XLPE samples.
Article
Engineering, Electrical & Electronic
Hyungjin Yoon, George Chen
Summary: This article investigates the impact of moisture on the space charge characteristics of natural ester oil-impregnated paper compared to mineral oil-impregnated paper. It is found that the hydrophilic characteristic of natural ester oil results in a slower process of heterocharge formation in the paper, whereas the hydrophobic characteristic of mineral oil leads to faster heterocharge formation.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Engineering, Electrical & Electronic
Tohid Shahsavarian, Xin Wu, Charles Lents, Di Zhang, Chuanyang Li, Yang Cao
Summary: This study investigates the surface discharge behavior of two commonly used high-temperature insulation materials, ETFE and PEEK, at different temperatures under ramp and DC voltages. It is found that ETFE exhibits higher intensity PDs at high temperatures above 100 degrees C, with a higher possibility of surface discharge due to its lower permittivity. The study provides a basis for the selection of high-temperature PD suppressing materials in DC voltage applications.
Article
Polymer Science
Yanhui Wei, Wang Han, Guochang Li, Xiaojian Liang, Zhenlu Gu, Kai Hu
Summary: This study investigated the aging characteristics and mechanism of oil-impregnated insulation paper under thermal stress, and determined the trap energy levels at different aging stages through experiments and simulations.
Article
Chemistry, Analytical
Conner C. Harper, Veena S. Avadhani, Emeline Hanozin, Zachary M. Miller, Evan R. Williams
Summary: Ion-ion interactions between simultaneously trapped ions have been studied in detail using a dynamic measurement method. The results show that these interactions have negligible effects on mass accuracy.
ANALYTICAL CHEMISTRY
(2023)
Article
Polymer Science
Yiwei Long, Jian Gao, Zhuolin Cheng, Daoyuan Chen, Kangning Wu, Jianying Li, Fusheng Zhou
Summary: The study revealed that the skin-core structure of thermally aged epoxy resin consists of the aged surface-layer and the unaged inner-layer, with a thickness of up to 0.09 mm, primarily formed due to thermal oxidation and re-crosslinking processes. The relaxation process of aged epoxy resin displayed higher relaxation time and strength, with a significant increase in trap densities.
POLYMER DEGRADATION AND STABILITY
(2021)
Article
Engineering, Electrical & Electronic
Meng Huang, Weiguang You, Yanyu Wu, Lei Zhang, Yiran Li, Chunjia Gao, Bo Qi
Summary: In this article, a pulsed electric-acoustic (PEA) - Kerr combined measurement method is proposed to measure the distribution of space charge and electric field of oil-paper composite insulation. The PEA-Kerr combined measurement system is built by integrating and optimizing the system structure and signal processing methods of PEA and Kerr measurement. The test results show good linearity and accuracy of the system.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Computer Science, Information Systems
Xiaozhen He, Paolo Seri, Ilkka Rytoluoto, Rafal Anyszka, Amirhossein Mahtabani, Hadi Naderiallaf, Minna Niittymaki, Eetta Saarimaki, Christelle Mazel, Gabriele Perego, Kari Lahti, Mika Paajanen, Wilma Dierkes, Anke Blume
Summary: This study compares the suitability of two polymer-nanofiller blends for HVDC cable application, indicating that the comprehensive performance of the PP/PP-HI composite is better than the one of the PP/EOC composite. The addition of nanosilica improves thermal stability and dielectric properties, but slightly increases conductivity.