基于改进强跟踪无迹卡尔曼滤波的电力系统同步相量估计方法  

Synchronous Phasor Estimation Method for Power System Based on Modified Strong Tracking Unscented Kalman Filter

作　　者：牛胜锁[1] 王康乐 梁志瑞[1] NIU Shengsuo;WANG Kangle;LIANG Zhirui(School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,Hebei Province,China)

机构地区：[1]华北电力大学电气与电子工程学院

出　　处：《电网技术》2019年第9期3218-3225,共8页Power System Technology

基　　金：国家重点研发计划项目(2017YFB0902901)~~

摘　　要：快速准确地获得电力信号的频率、幅值和相角,对于同步相量测量技术在配电网中的推广应用具有重要意义。配电网信号具有高噪声、强瞬变等特点,应用目前的算法在实时跟踪瞬变信号方面,其性能不太理想。针对强瞬变环境下的信号参数估计问题展开分析,提出一种改进的强跟踪无迹卡尔曼滤波(modified strong tracking unscented Kalman filter,MSTUKF)算法。首先分析了强跟踪滤波算法(strong tracking filter,STF)的基本原理,然后基于无损变换理论,对STF算法进行等价推导。在此基础上,针对状态方程为线性,量测方程为非线性的情况,提出一种在频率、幅值和相角突变时的快速跟踪算法。在sigma点集中引入渐消因子,使得算法仅需进行一次无损变换,简化了计算。同时将渐消因子引入输出协方差矩阵,改善算法在系统参数突变时的稳定性。仿真结果表明,所提同步相量测量算法能快速地对频率、幅值和相角进行跟踪,并且收敛性好、测量精度高。Fast and accurate acquisition of the frequency,amplitude and phase angle of power signal is of great significance for popularization and application of synchronous phasor measurement technology in distribution network.Distribution network signal has the characteristics of high noise,strong transient,etc.The performance of current algorithm in real-time tracking of transient signals is not ideal.This paper analyzes the signal parameter estimation problem in strong transient environment and proposes a modified strong tracking unscented Kalman filter(MSTUKF)algorithm.Firstly,the basic principle of strong tracking filter(STF)is analyzed.Then,based on unscented transform theory,an STF algorithm is equivalently deduced.On this basis,a fast tracking algorithm for mutation of frequency,amplitude and phase angle is proposed for the case where the state equation is linear and the measurement equation is nonlinear.Introduction of fading factor into sigma point set makes the algorithm only need to perform an unscented transformation,thus simplifying the calculation.At the same time,the fading factor is introduced into the output covariance matrix to improve stability of the algorithm when the system parameters are mutational.Simulation results show that the proposed synchronized phasor measurement algorithm can quickly track frequency,amplitude and phase angle with good convergence and high measurement accuracy.

关 键 词：相量估计 强瞬变 STF滤波算法 无损变换 渐消因子 

分 类 号：TM721[电气工程—电力系统及自动化]