基于频域特征结构的新能源电力系统宽频带振荡分析方法  

Wideband Oscillation Analysis Method of Renewable Energy Power System Based on Frequency Domain Eigenstructure

作　　者：周佩朋 孙华东 宋瑞华 刘涛 吕思琦 任必兴 ZHOU Peipeng;SUN Huadong;SONG Ruihua;LIU Tao;LYU Siqi;REN Bixing(State Key Laboratory of Power Grid Safety and Energy Conservation(China Electric Power Research Institute),Haidian District,Beijing 100192,China;State Grid Jiangsu Electric Power Company Ltd.Research Institute,Nanjing 211103,Jiangsu Province,China)

机构地区：[1]电网安全与节能国家重点实验室(中国电力科学研究院有限公司),北京市海淀区100192 [2]国网江苏省电力有限公司电力科学研究院,江苏省南京市211103

出　　处：《中国电机工程学报》2025年第6期2057-2070,I0002,共15页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：国家电网有限公司科技项目(5100-202155430A-0-0-00)。

摘　　要：新能源电力系统的宽频带振荡现象具有多场站共同参与、振荡源特性复杂等特点,以阻抗法为代表的单变量频域方法对复杂结构系统的适用性不足,而以时域分析的特征值法则受限于系统阶数且无法处理封装模型。该文从多变量频域理论出发,首先,将电力网络进行频域等值,形成以各场站作为控制通道的等效多变量控制系统模型;其次,通过与时域状态矩阵的特征值相类比,提出频域回比矩阵特征函数表征多变量系统的不同控制模式,将其物理意义表述为具有共模和差模特征的电路谐振回路,采用主导特征函数判断稳定性;然后,依据回比矩阵的特征方向定义各场站对主导控制模式的贡献因子,以定量评估各场站对振荡影响的程度、性质并提出振荡源定位方法;此后,通过近似描述新能源场站导纳特性,将目标频段主导特征函数的值作为简化的振荡风险评估指标;最后,基于实际电网构建工程算例,针对弱接入系统下的次同步振荡现象开展分析,验证所提方法的应用效果。Wideband oscillation in renewable energy power system is characterized by the participation of multiple stations and complex oscillation source feature,among other attributes.Single-variable frequency domain method represented by impedance method is not suitable for complex structural systems,while the eigenvalue method in time-domain analysis is limited by the system order and cannot deal with the packaging model.In this paper,based on the theory of multivariable frequency domain,the equivalent multivariable control system model with each station as a control channel is formed by frequency domain equivalent of power network.Then,by comparing with the eigenvalues of the time-domain state matrix,the eigenvalue functions of the frequency-domain loop-ratio matrix are proposed to represent the different control modes of the multivariable system,and their physical meaning is expressed as a resonant circuit with common mode and differential model characteristics.The stability is evaluated using the dominant eigenvalue function.Subsequently,contribution factors for each station to the dominant control mode are defined based on the eigendirection of the loop-ratio matrix.This allows for a quantitative assessment of the degree and nature of each station's impact on the oscillation.Furthermore,a method for locating the oscillation source is proposed.Then,input admittance of the renewable energy station is described approximately,and the value of dominant eigenvalue function of the target frequency band is used as a simplified oscillation risk assessment index.Finally,an engineering example is constructed based on the actual power grid,sub-synchronous oscillation in weak grid is analyzed,and the application effect of the proposed method is verified.

关 键 词：多变量频域理论 特征函数 特征方向 模式 振荡源 

分 类 号：TM73[电气工程—电力系统及自动化]