个人信息Personal Information
教授
博士生导师
硕士生导师
性别:男
毕业院校:大连理工大学
学位:博士
所在单位:电气工程学院
学科:电机与电器. 高电压与绝缘技术. 电力电子与电力传动
办公地点:大连理工大学电气工程学院电力电子研究所407
联系方式:mfliao@dlut.edu.cn
电子邮箱:mfliao@dlut.edu.cn
Statistical analysis of switching overvoltages in UHV transmission lines with a controlled switching
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论文类型:期刊论文
发表时间:2019-11-05
发表刊物:IET GENERATION TRANSMISSION & DISTRIBUTION
收录刊物:EI、SCIE
卷号:13
期号:21
页面范围:4998-5004
ISSN号:1751-8687
关键字:overvoltage protection; arcs (electric); power engineering computing; power transmission lines; electric breakdown; electric strength; circuit breakers; statistical analysis; switching overvoltages; UHV transmission lines; precisely controlled switching strategy; electric field variation; arc-extinguish chamber; RDDS; controlled closing; overvoltage simulations; ultrahigh voltage transmission line closing; prebreakdown instants; statistical analysis
摘要:The objective of this work is to present a more precisely controlled switching strategy to reduce overvoltages due to ultra-high voltage (UHV) transmission line closing. Essentially the switching strategy is to find a suitable circuit breaker (CB) optimal instant of closing. The electric field variation in the arc-extinguish chamber has great effect on rate of decrease of dielectric strength (RDDS), when calculating optimal instant of closing with pre-breakdown between the contacts. The relative value k of a CB is defined as the ratio of RDDS to the rate of voltage approaching the zero cross. In this calculation, the electric field E should be as a variation due to the uneven medium of SF6. Consequently equations were derived from calculating the pre-breakdown instants. The ATP model of controlled closing UHV transmission line was built for switching overvoltage simulations considering RDDS and mechanical dispersion. The simulation results show that switching overvoltages are more accurate and closer to reality when regarding the electric field E as a variation. Contrarily, assuming E as a constant will increase the risk of failure via controlled switching. Furthermore, the simulation results demonstrate that k value can change the effect of the mechanical dispersion on switching overvoltages.