Article
Engineering, Electrical & Electronic
Jin Li, Yuhuai Wang, Xiaohui Duan, Jianwei Wei, Yaxiang Wang, Hucheng Liang, Boxue Du
Summary: In this article, the surface charge distribution and flashover characteristics of epoxy basin insulators in a down-sized dc-gas-insulated switchgear were studied under ac-dc composite voltage. The results indicated that higher composite voltage amplitude led to more heteropolar charges on the surface of the insulator, which tended to diffuse towards the central high-voltage electrode. Higher prestressing resulted in a decline in the ac component but an increase in the absolute amplitude of the flashover voltage. Direct ramp voltage stressing showed higher flashover voltage compared to prestressing. The surface modification of the insulators through direct fluorination improved the surface charge distribution and flashover voltage.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Energy & Fuels
Xin Wang, Zhimin Wang, Jieyuan Chen, Xiaofei Shi, Xiaolong Li
Summary: This paper investigates the substitutability of SF6/CF4 mixture in surface flashover property. The results show that the flashover voltage in the mixture achieves more than 70% of SF6 voltage at the same pressure. The mixture exhibits considerable synergy and different tendencies under different electrode systems due to the influence of surface accumulated charge.
Article
Polymer Science
Qi Hu, Qingmin Li, Zhipeng Liu, Naifan Xue, Hanwen Ren, Manu Haddad
Summary: This paper investigates the influence of metal contaminants on the surface charge accumulation and flashover of tri-post epoxy insulators under the superimposed DC and lightning impulse voltage. Experimental results show that metal particles can significantly increase the surface charge density of the insulator and cause polarity reversal of adjacent surface charges. Moreover, the presence of metal dust leads to a greater reduction in the surface flashover voltage compared to attached metal particles. The research findings provide insights for the insulation test method and optimal design of DC tri-post epoxy insulators.
Article
Engineering, Electrical & Electronic
Bo Qi, Zhuodong Yang, Xiao Yang, Chunjia Gao, Licheng Lu, Yi Zhang, Li Li, Caixin Sun, Chengrong Li
Summary: This article investigates the flashover characteristics of epoxy samples in SF6 gas in DC wall bushing and analyzes the flashover process through surface charge distribution measurement and electric field computation.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Physics, Applied
Pu Han, Zijun Pan, Shiyi Mao, Yuhan Ye, Ju Tang, Cheng Pan
Summary: Charge accumulation at the insulator surface can significantly change the electric field distribution and cause unpredictable flashover under DC voltage. This study proposed a method to judge the moment approaching flashover and investigated the dynamic distributions of surface charges, including the charge distribution approaching flashover occurrence. The analysis of flashover on insulators coated in SiC/epoxy revealed a reversal of charge polarity during voltage rising and a relationship between charge distribution approaching flashover and flashover voltage, where an increase in SiC content resulted in greater charge accumulation and enhanced flashover voltage through weakening the electric field.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Physics, Applied
Chuanyang Li, Yujie Zhu, Jun Hu, Qi Li, Bo Zhang, Jinliang He
Summary: This paper reports an unpredictable insulation surface flashover phenomenon triggered by surface charge clusters under DC electric field. The mechanism of flashover and the influence of dust phase transition on the evolution of charge clusters are illustrated. This unpredictable phenomenon has significant implications for HVDC power transmission systems and fields such as microelectronics.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Chuyu Sun, Shengchang Ji, Linshen Xie, Haiyang Wang, Kaisheng Mei
Summary: Surface flashover of dielectric materials can cause significant damage to pulse power devices. This is particularly challenging as higher operating voltages are demanded. To address this issue, the flashover voltage and streamer development characteristics were studied in pressured SF6 gas under positive and negative nanosecond impulses. The results demonstrated that the negative flashover voltage was higher than the positive one. The study also examined the evolving process of streamers using a high-speed camera and analyzed the surface morphology change after flashover. Possible mechanisms for polarity and pressure effects were proposed.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Review
Engineering, Electrical & Electronic
Jixing Sun, Sibo Song, Jingquan Zheng, Zongze Li, Jindong Huo, Yifei Wang, Peng Xiao, Shakeel Akram, Dehao Qin
Summary: This article reviews the history and key issues of surface flashover of insulators at dc voltage in compressed gas and vacuum, discusses influencing factors, summarizes theoretical models, concludes related problems, and prospects for future work.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Review
Nanoscience & Nanotechnology
Zhousheng Zhang, Zheming Wang, Gilbert Teyssedre, Tohid Shahsavarian, Mohamadreza Arab Baferani, Geng Chen, Chuanjie Lin, Bo Zhang, Uwe Riechert, Zhipeng Lei, Yang Cao, Chuanyang Li
Summary: This paper classifies and reviews surface charge tailoring techniques, comparing technical solutions and discussing potential approaches to suppress charge accumulation based on industrial considerations. It serves as a guide for engineers and researchers and aims to promote the industrial application of charge-free insulators in HVDC GIL/GIS.
Article
Engineering, Electrical & Electronic
Yushuang He, Feipeng Wang, Li He, Qiang Wang, Jian Li, Yihua Qian, Reimund Gerhard, Ronald Plath
Summary: This study investigates the effect of nano-Al2O3 on the surface charge and dc flashover performance of epoxy resin. The results show that nano-Al2O3 can reduce the size of the equipotential zone and improve the high resistance of epoxy resin to multiple flashovers.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Engineering, Electrical & Electronic
Lu Fan, Yi Yin, Yalin Wang
Summary: An online surface potential measurement method is proposed and verified in this article to explore the dc flashover characteristics and evaluate the dc flashover resistance of epoxy resin. The results show that positive and negative flashover exhibit different surface potential evolution characteristics, with positive flashover being more severe than negative flashover.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Physics, Applied
Fang-cheng Lu, Pin Lu, Hao-ou Ruan, Shuang-shuang Wang, Shuai-tao Mao, Sheng-hui Wang, Qing Xie
Summary: The paper explores enhancing the flashover voltage of disc insulators in gas insulated transmission lines by adjusting the surface conductivity distribution. Through plasma fluorination and the addition of different ring polytetrafluoroethylene baffles, gradient distribution of surface conductivity is achieved to decrease electric field intensity and increase flashover voltage.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Physics, Applied
Bo Qi, Zhuodong Yang, Xiao Yang, Meng Huang, Chunjia Gao, Yi Zhang, Yuan Luo, Licheng Lu, Chengrong Li
Summary: Epoxy post-insulator is a crucial component in SF6 gas-insulated DC wall bushing and plays an irreplaceable role in high voltage direct current transmission projects. Flashovers occur frequently on the post-insulators due to the presence of numerous tiny metal particles, which alter the insulation state of the surface. However, the relationship between the microstructure of the material and the macroscopic electrical properties during flashovers remains controversial. To investigate the impact of particles on flashover characteristics, particles generated from wear of the spring in the DC wall bushing were selected. The study measured the surface potential decay and the DC flashover voltage of epoxy attached with particles.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Zhenlian An, Jingpeng Sun, Yong Yang, Fang Liu, Xuguang Liu
Summary: The direct fluorination process significantly improves the dc flashover performance of gas insulated switchgear (GIS) by increasing the flashover voltage and reducing voltage dispersion. The fluorination temperature has a significant impact on the enhancement of the flashover voltage. The improvement in flashover performance is mainly attributed to the increase in surface conduction, which suppresses surface charge accumulation.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Materials Science, Composites
Zimin Luo, Yushun Zhao, Jinhui Bai, Kerong Yang, Yufan Xu, Lijian Ding, Bin Du
Summary: This study presents a new approach to enhance the surface-insulating performance of epoxy composites by constructing peak-type charge barriers using nanodiamonds (NDs). The constructed barriers alter the charge migration behavior and improve the charge dissipation rate, surface flashover voltage, and arc resistance duration of the ND/epoxy composite.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)