摘要
提出一种基于铁氧体磁环和RC阻容吸收器的方法来抑制海上风电场高频暂态过电压。由于海上风电场电缆集电系统中的行波折射和反射现象,在真空断路器分合闸发生重燃和预击穿时,在机端变压器高压侧产生高幅值、高陡度的暂态过电压,该过电压会对变压器匝间的绝缘产生严重损害。因此,首先通过电磁暂态仿真软件ATP-EMTP搭建海上风电场集电系统中电缆、变压器、真空断路器仿真模型,然后按照实际海上风电场搭建完整的集电系统。研究真空断路器触头分离速度、合闸相位、电缆长度对高频暂态过电压的影响,并提出在真空断路器附近或机端变压器高压侧安装RC阻容吸收器、铁氧体磁环以抑制高频暂态过电压的方法。研究表明:真空断路器在分闸时,在电压峰值即相位角为90°时的过电压幅值最小,在电压零点位置即相位角为180°时的过电压幅值最大;暂态过电压随着电缆的长度的增加而减小;相比RC阻容吸收器,装设铁氧体磁环过电压保护装置抑制海上风电场产生极高频暂态过电压的效果更显著。
A method based on ferrite magnetic ring and RC absorber is proposed to suppress high-frequency transient overvoltage in offshore wind farms.Due to the phenomenon of traveling wave refraction and reflection in the cable collecting system of offshore wind farm,the transient overvoltage with high amplitude and high gradient will be generated on the high voltage side of the transformer when the vacuum circuit breaker is re-burning or pre-breakdown during the opening and closing.Therefore,in this paper,the simulation model of cable,transformer and vacuum circuit breaker in the collecting system of offshore wind farm is first built on ATP-EMTP,and then a complete collecting system is built according to the actual offshore wind farm.The effects of contact separation speed,closing phase and cable length on high frequency transient overvoltage of vacuum circuit breaker are studied,and a method to restrain high frequency transient overvoltage is proposed by installing RC absorber and ferrite magnetic ring near the vacuum circuit breaker or on the high voltage side of transformer at the end of the machine.The results show that when the vacuum circuit breaker is open,the overvoltage amplitude is the smallest when the voltage peak is 90°,and is the largest when the voltage zero is 180°.The transient overvoltage decreases with the increase of cable length.The installation of magnetic loop overvoltage protection device is more effective than RC absorber in restraining the very high frequency transient overvoltage generated by offshore wind farms.
作者
孙文艺
李勇
辛道越
彭哲
李伟
Sun Wenyi;Li Yong;Xin Daoyue;Peng Zhe;Li Wei(Guangdong Mingyang Electronics Co.,Ltd.,Zhongshan,Guangdong 528400,China;School of Electrical Engineering and Electronic Information,Xihua University,Chengdu 610039,China)
出处
《机电工程技术》
2023年第9期241-245,251,共6页
Mechanical & Electrical Engineering Technology
关键词
海上风电场
重燃
高频暂态过电压
过电压保护
offshore wind farms
reignition
high frequency transient over-voltage
over-voltage protection
