基于扩展卡尔曼滤波频率跟踪的DFT同步相量测量算法

发布时间：2019-04-03 13:05

【摘要】：当电力信号的频率发生偏移时,采用离散傅里叶变换(discrete Fourier transformation,DFT)进行同步相量测量难以做到同步采样,由此造成的栅栏效应严重影响了同步相量测量精度。为此提出一种改进的DFT同步相量测量算法。首先引入了基于扩展卡尔曼滤波(extended Kalman filter,EKF)的频率跟踪算法,建立了基波频率测量的算法流程,并介绍了基于DFT的同步相量测量算法原理。在此基础上,将测量结果分为整数部分和分数部分,分析了因频率偏移导致的相量测量误差,对分数部分进行插值计算以提高同步相量测量精度。分别应用含谐波和噪声的稳定信号和幅值、相位、频率、谐波及噪声含量跳变的信号来校验算法的性能。仿真结果表明,EKF频率跟踪算法能快速对基波频率进行跟踪,所提出的同步相量测量算法能消除或减弱谐波、噪声以及频率偏移对同步测量的影响,提高了相量测量精度。
[Abstract]:The synchronous phasor measurement using discrete Fourier transform (discrete Fourier transformation,DFT) is difficult to achieve synchronous sampling when the frequency of power signal is shifted, which results in the fence effect seriously affecting the accuracy of synchronous phasor measurement. An improved DFT synchronous phasor measurement algorithm is proposed. First, the frequency tracking algorithm based on extended Kalman filter (extended Kalman filter,EKF) is introduced, the algorithm flow of fundamental frequency measurement is established, and the principle of synchronous phasor measurement algorithm based on DFT is introduced. On this basis, the measurement results are divided into integer part and fractional part. The phasor measurement error caused by frequency offset is analyzed, and the fractional part is interpolated to improve the accuracy of synchronous phasor measurement. The stability signal and amplitude, phase, frequency, harmonic and noise content hopping signal with harmonic and noise are used to verify the performance of the algorithm. The simulation results show that the EKF frequency tracking algorithm can track the fundamental frequency quickly. The proposed synchronous phasor measurement algorithm can eliminate or reduce the influence of harmonic noise and frequency offset on synchronous measurement and improve the accuracy of phasor measurement.
【作者单位】：西南交通大学电气工程学院;
【基金】：国家863高技术基金项目(2012AA050208) 国家自然科学基金重点项目(U1234203) 中央高校基本科研业务费专项资金(SWJTU2011CX004EM)~~
【分类号】：TM933.31

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