摘要
长距离架空输电线、电缆存在较大的对地分布电容,易引起风电并网系统的谐振等问题。为了分析大规模风火打捆半波长交流输电系统的谐波谐振放大特性,基于选择性模态分析,推导得到谐波谐振传输放大解耦矩阵,使用交互参与因子评估谐波扰动源对系统任意节点的激励作用,确定易受谐波传输放大影响的节点。针对实际风电并网系统中含量较大的特征谐波,分析不同风电占比情况下发生谐振时系统各节点的谐波电压响应;引入元件标准化灵敏度及其主导系数,分析综合考虑了各谐振情况后的元件灵敏度,为能够同时抑制多种谐波谐振放大或次谐波谐振提供理论依据。研究表明,风火打捆半波长交流系统中可能发生谐波谐振放大的现象;随着风电占比的增加,谐振频率逐渐降低; 35 kV及110 kV电压等级的母线受7、11次谐波谐振放大的影响严重,可能危害系统的安全运行;半波长线路首、末端基本不受谐波传输放大的影响,可以安全运行。利用PSCAD进行模拟计算,结果验证了所提方法的有效性。
Large distributed capacitors between ground and long distance overhead transmission lines and cables can easily cause the harmonic resonance problems for the grid-connected wind power system. In order to analyze the harmonic resonance amplification characteristics of the large-scale wind-thermal-bundled half-wavelength AC transmission system,the decoupling matrix of harmonic resonance transmission and amplification is derived based on the selective modal analysis. The interactive participation factor is used to evaluate the excitation effect of harmonic disturbance sources on any nodes in the system,and to determine the nodes which are easily affected by the harmonic resonance transmission and amplification. The harmonic response voltage of each node caused by the characteristic harmonics,which have larger contents in the actual grid-connected wind power system,is analyzed according to the different proportions of wind power when the resonance happens. The standardized sensitivity and its dominant coefficient are introduced to analyze the element sensitivity with a comprehensive consideration of various resonance conditions,which can provide a theoretical basis for suppressing multiple harmonic resonance amplification or subharmonic resonance simultaneously. Simulation shows that,there may have harmonic resonance amplification in the wind-thermal-bundled half-wavelength AC transmission system. As the proportion of wind power increases,the resonance frequency decreases gradually. The 7 th and 11 th harmonic resonance amplifications have serious influences on the 35 kV and 110 kV buses,which may endanger the safe operation of the system. The head and end of the halfwavelength transmission line are not affected by the harmonic resonance transmission and amplification and can operate safely. The simulation is carried out with PSCAD to verify the effectiveness of the proposed method.
作者
陈畅
杨洪耕
CHEN Chang;YANG Honggeng(School of Electrical Engineering and Information,Sichuan University,Chengdu 610065,China)
出处
《电力自动化设备》
EI
CSCD
北大核心
2019年第2期50-57,64,共9页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(51477105)~~
关键词
风火打捆
半波长输电线路
交流输电系统
模态分析
谐波谐振
参与因子
标准化灵敏度
wind-thermal-bundled
half-wavelength transmission line
AC transmission system
modal analysis
harmonic resonance
participation factor
standardized sensitivity
作者简介
陈畅(1992-),女,辽宁抚顺人,博士研究生,主要研究方向为谐波分析与建模(E-mail:412355373@qq.com);通信作者:杨洪耕(1949-),男,四川成都人,教授,博士,主要研究方向为电能质量、智能电网等(E-mail:pqlab99@126.com)。
