一种改进三角变换的频率检测新方法  

A New Modified Trigonometric Transform Based Method for Power Frequency Detection

作　　者：罗志坤[1] 陈福胜[1] 王海元[1] 徐先勇[1] 

机构地区：[1]国网湖南省电力公司电力科学研究院,湖南省长沙市410007

出　　处：《电网技术》2015年第2期563-567,共5页Power System Technology

摘　　要：在电网频率波动时,采用d-q变换法和Kalman滤波法难以准确检测出电压骤降特征值。为解决此难题,以Matlab7.6为实验平台进行了大量的仿真和数据分析,并通过原理推导,发现当电网实际频率与算法中变换矩阵的预置频率不一致时,信号的相位时间曲线不再是一条平行于时间轴的直线,而是呈一次函数关系的斜线,并且随着频率的偏差变化,一次函数曲线的斜率也会相应增大或减小。在此基础上首次推导出相位时间曲线斜率k1与频率偏差值f之间的数学关系式。将该方法与常规Kalman滤波法和d-q变换法相结合,能够对被测信号实时跟踪,当被测信号频率变化时,能快速准确检测信号频率波动变化时的幅值和相位。该方法在信号的量值检测中具有广阔的应用前景。It is hardly to detect the eigenvalue of voltage sag accurately by d-q transform and Kalman filtering method during power frequency fluctuation. To solve this probem, taking Matlab 7.6 as the experimental platform a lot of simulation and data analysis are performed, and through the principle derivation it is found that when actual grid frequency differs from the preset frequency of the transform matrix in the algorithm, the phase vs. time curve of the signal is no longer a straight line that is parallel to the time axis but an oblique line that belongs to linear function, and with the change of frequency deviation the slope of the linear function increases or decrease correspondingly. On this basis, it is the first time that the mathematical relationship between the slope k1 of the phase vs. time curve and the frequency deviation △f is deduced. Combining the deduced method with Kalman filtering method and d-q transform, the real-time tracking of the measured signal can be implemented, and both amplitude and phase angle of the measured signal can be detected fast and accurately during the frequency fluctuation of the measured signal.

关 键 词：D-Q变换 KALMAN滤波 相位时间曲线 频率补偿 量值检测 

分 类 号：TM721[电气工程—电力系统及自动化]