基于改进DFT的电力系统同步相量测量算法研究

发布时间：2018-04-22 07:17

本文选题：离散傅里叶变换 + 频谱泄露　；参考：《电工技术学报》2017年17期

【摘要】：离散傅里叶变换(DFT)在相同条件下,具有运算效率高、易于嵌入等优点,被广泛应用于电力系统同步相量测量中。但由于非同步采样及频域离散化问题的存在,DFT在进行相量测量时会出现频谱泄露和栅栏效应,使得计算结果产生误差。针对这一问题,推导了DFT在非同步采样情况的相角误差方程,利用相角差对信号频率进行跟踪测量,得到精度较高的频率值。据此,提出了基于改进DFT的同步相量测量方法,利用跟踪所得频率将DFT结果分为整数部分和分数部分,并通过等效替换对分数部分进行了修正。经仿真实验证明,该方法具备较高的抗干扰能力和测量精度,整体效果较传统算法有了很大的提升。在此基础上,利用TMS320F2812设计了一个同步相量测量装置(PMU)硬件系统,通过该系统实现了频率、幅值和相角的准确测量。
[Abstract]:Discrete Fourier transform (DFT) is widely used in synchronous phasor measurement of power system due to its high computational efficiency and easy embedding under the same conditions. However, due to the existence of asynchronous sampling and frequency domain discretization, the frequency spectrum leakage and fence effect will occur in DFT for phasor measurement, which results in the error of the calculation results. To solve this problem, the phase angle error equation of DFT in the case of asynchronous sampling is derived. The frequency of the signal is tracked and measured by using the phase angle difference, and the frequency value with high precision is obtained. Based on this, a synchronous phasor measurement method based on improved DFT is proposed. The DFT results are divided into integral part and fractional part by tracking frequency, and the fractional part is modified by equivalent substitution. The simulation results show that the method has high anti-interference ability and measurement accuracy, and the overall effect is much better than that of the traditional algorithm. On this basis, a synchronous phasor measuring device (PMU) hardware system is designed by using TMS320F2812, through which the accurate measurement of frequency, amplitude and phase angle is realized.
【作者单位】：福州大学电气工程与自动化学院;国网福建电力有限公司南平供电公司;
【基金】：欧盟FP7国际科技合作基金(909880) 国家自然科学基金(61304260) 福建省杰出青年科学基金(2012J06012)资助项目
【分类号】：TM933.313

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