摘要
针对混合高压直流输电线路距离长、故障率高的问题,提出了一种适用于±500 kV的混合直流输电线路的保护方法。根据混合双极高压直流输电线路边界元件两侧的信号高低频能量不同,同时考虑到故障类型以及过渡电阻对诊断结果的影响,构造了有功功率故障分量的暂态能量比值的保护方法。该方法利用小波包变换对有功功率故障分量分解,得到各节点暂态能量;利用正、负极能量比值的大小区分区内、外故障,根据正、负极能量比值的差值区分单、双极故障,并利用正、负极部分频带能量和进行故障选极。采用电磁仿真软件PSCAD/EMTDC搭建±500 kV混合双极高压直流输电系统仿真模型,并利用MATLAB结合保护判据进行保护算法的仿真验证,结果表明:所提方法耐过渡电阻能力高,数据采集时间窗为3 ms,在不同的工况下都可以快速、准确识别区内外故障,并具有故障选极功能。
Aiming at the problems of long distance and high failure rate of hybrid bipolar high voltage direct current(HVDC)transmission lines,a relay protection method suitable for±500 kV hybrid DC transmission lines is proposed.According to the different high and low frequency energy of the signals on the two sides of the boundary element of the hybrid bipolar HVDC transmission line,and considering the type of fault and the influence of the transition resistance on the result,a protection scheme for the transient energy ratio of the active power fault component is constructed.This method adopts wavelet packet transform to decompose the active power fault component to obtain the transient energy of each node.The positive and negative energy ratios are used to distinguish between internal and external faults,the differences between positive and negative energy ratios are taken to distinguish single faults from bipolar ones,and the positive and negative part of the frequency band energy sum is applied to fault selection.The electromagnetic simulation software PSCAD/EMTDC is chosen to constructed a±500 kV hybrid bipolar HVDC transmission system simulation model,and MATLAB is used to combine the protection criteria to perform the simulation verification of the protection algorithm.This proposed method is endowed with high resistance to transient resistance and a data acquisition time window of 3 ms,which enables to quickly and accurately identify internal and external faults under different operating conditions with a fault pole selection function.
作者
高淑萍
叶换飞
宋国兵
张楚
牛丹
GAO Shuping;YE Huanfei;SONG Guobing;ZHANG Chu;NIU Dan(School of Electrical and Control Engineering, Xi’an University of Science and Technology, Xi’an 710054, China;Yulin Power Supply Company, State Grid Shaanxi Electric Power Company, Yulin, Shaanxi 719000, China;School of Electrical Engineering, Xi’an Jiaotong University, Xi’an 710049, China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2020年第6期36-43,共8页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51777166)
国家自然科学基金联合基金重点资助项目(U1766209)。
关键词
混合双极高压直流输电
继电保护
有功功率故障分量
暂态能量
小波包变换
hybrid bipolar high-voltage direct current transmission system
relay protection
active power fault component
transient energy
wavelet packet transform
