一种基于圆周运动轨迹方程的电力系统基波频率测量方法  

A Method for Estimating the Fundamental Frequency of Power Systems Based on the Circular Motion Trajectory Equation

作　　者：许苏迪 袁宇波 王晨清 郑明忠 高磊 XU Sudi;YUAN Yubo;WANG Chenqing;ZHENG Mingzhong;GAO Lei(State Grid Jiangsu Electric Power Co.,Ltd.,Research Institute,Nanjing 211103,Jiangsu Province,China)

机构地区：[1]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：《电网技术》2024年第7期2919-2927,共9页Power System Technology

基　　金：国网江苏省电力有限公司科技项目(J2022025)。

摘　　要：随着新能源的大规模接入,系统惯量降低,电力系统的频率波动变得剧烈,增加了频率准确测量的难度,而频率的测量精度直接关系着电力系统各类基于频率控制应用的有效性。因此,该文从圆周运动角度,提出了一种新颖的频率精确测量方法。该方法建立了电力系统电压信号正弦变化的旋转相量圆周运动表征模型,基于匀速圆周运动和变速圆周运动的轨迹运动方程,推导了旋转相量及其导数与系统频率之间的函数关系;利用二次多项式拟合电压信号动态变化的幅值和相角,提出了基于最小二乘法的旋转相量及其导数求解方法,进一步,提出了基于频率网格化的迭代优化方法,消除了频率偏移对算法的影响。仿真和硬件测试表明,所提算法在频率偏移、线性和非线性变化条件下均能准确地测量基波频率。With the large-scale integration of new energy,the inertia of the power system decreases,and the frequency fluctuations in the power system become severe,increasing the difficulty of accurate frequency measurement.The frequency measurement accuracy directly affects the effectiveness of various frequency control applications in the power system.Therefore,this paper proposes a novel,accurate frequency measurement method from the perspective of circular motion.This method establishes the circular motion representation model of the rotating phasor of the sinusoidal voltage signal.Then,based on the trajectory motion equations of the uniform and non-uniform circular motions,the functional relationship between the rotating phasor and its derivative and the system frequency is derived.Furthermore,using quadratic polynomials to fit the dynamic amplitude and phase angle of voltage signals,a method based on the least squares method for solving rotating phasors and their derivatives is put forward.In addition,an iterative optimization method based on a frequency grid is proposed to eliminate the impact of frequency offset on the algorithm.Simulation and hardware test results show that the proposed algorithm can accurately measure the fundamental frequency under frequency offset,linear,and nonlinear changes.

关 键 词：频率测量 旋转相量 圆周运动 最小二乘法 

分 类 号：TM721[电气工程—电力系统及自动化]