基于Vector Fitting的光伏并网逆变器控制器参数频域辨识方法  

Frequency-domain identification method for controller parameters of photovoltaic grid-connected inverter based on Vector Fitting

作　　者：王哲[1] 吕敬[1] 吴林林 王潇 宗皓翔 蔡旭[1] WANG Zhe;Lü Jing;WU Linlin;WANG Xiao;ZONG Haoxiang;CAI Xu(Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education,Shanghai Jiao Tong University,Shanghai 200240,China;State Grid Jibei Electric Power Co.,Ltd.Research Institute,Beijing 100045,China)

机构地区：[1]上海交通大学电力传输与功率变换控制教育部重点实验室,上海200240 [2]国网冀北电力有限公司电力科学研究院,北京100045

出　　处：《电力自动化设备》2022年第5期118-124,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51907125)。

摘　　要：光伏并网逆变器通常含有内外环、锁相环等不同带宽控制环节,且控制器参数往往并不可知,即存在“灰箱”问题。为准确辨识不同带宽控制器参数,提出一种基于端口导纳特性的光伏并网逆变器控制器参数频域辨识方法。首先,建立典型控制下光伏并网逆变器交流端口的dq理论导纳模型,得到其理论导纳标准式;然后,通过扫频手段获得光伏并网逆变器交流端口的测量导纳数据,并采用Vector Fitting算法对测量的端口导纳数据进行矢量拟合,得到拟合导纳标准式;最后,运用最小二乘原理使理论导纳标准式与拟合导纳标准式对应项系数差值的平方和最小,从而辨识得到光伏并网逆变器控制器参数的估计值。参数辨识实例表明,所提方法能够同时准确辨识出不同带宽控制器参数。Photovoltaic grid-connected inverters usually contain multi-bandwidth control links,including inner and outer loops as well as phase locked loop,and the controller parameters are often unknowable,that is,there is a “gray box” problem. In order to accurately identify the control parameters of various control links with different bandwidths,a frequency-domain identification method for the controller parameters of photovoltaic grid-connected inverters based on port admittance characteristics is proposed. Firstly,the theoretical dq admittance model of a typical photovoltaic grid-connected inverter is established and its theoretical admittance standard formula is obtained. Then,the measured AC port admittance data of the photovoltaic grid-connected inverter is obtained through frequency sweeping,and the Vector Fitting algorithm is used to perform vector fitting on the measured admittance data to obtain the fitted admittance standard formula.Finally,the least square principle is used to minimize the sum of squares of the difference between the coefficients of the corresponding terms in the theoretical admittance standard formula and the fitted admittance standard formula,thus the estimated values of controller parameters of photovoltaic grid-connected inverter are identified. The parameter identification case shows that the proposed method is able to accurately identify all controller parameters with different bandwidths.

关 键 词：光伏并网逆变器 参数辨识 导纳特性 Vector Fitting算法 多带宽控制 

分 类 号：TM615[电气工程—电力系统及自动化] TM464