作者：王海元1,2, 郭光1,2, 李恺1,2, 尹晓博1, 邵喜瑞3, 温和3
作者单位：1. 国网湖南省电力有限公司，湖南 长沙 410000;
2. 智能电气量测与用电技术湖南省重点实验室，湖南 长沙 410000;
3. 湖南大学电气与信息工程学院，湖南 长沙 410082
关键词：频率计量;傅里叶变换;噪声;谐波
摘要：
电力系统频率估计不可避免地受到噪声和谐波影响，准确度受到限制。傅里叶变换是频率估计的常用工具，但其固有的频谱泄漏，特别是负频谱导致的长频程泄漏，是短测量时间内难以实现频率准确估计的重要因素。该文提出一种基于矩形窗的复频域插值傅里叶变换频率估计方法，建立噪声影响下的频率估计理论方差模型，并通过仿真验证方差模型的正确性。该算法考虑负频谱导致的长频程泄漏影响，在测量窗口长度小于2个基波周期时，仍具有较高的频率估计精度。仿真和实验表明，在存在噪声和谐波的情况下，当测量窗口较短时，该算法的频率估计性能优于现有的频率估计算法。
Complex frequency domain interpolation frequency estimation method considering white noise and harmonic effects
WANG Haiyuan1,2, GUO Guang1,2, LI Kai1,2, YIN Xiaobo1, SHAO Xirui3, WEN He3
1. State Grid Hunan Electric Power Company Limited, Changsha 410000, China;
2. Hunan Province Key Laboratory of Intelligent Electrical Measurement and Electricity Technology, Changsha 410000, China;
3. College of Electrical and Information Engineering,Hunan University, Changsha 410082, China
Abstract: In the power system, frequency estimation is inevitably affected by noise and harmonics, so accuracy is limited. The Fourier Transform is a common tool for frequency estimation, but it has a problem of spectrum leakage, especially the long-range leakage caused by negative spectrum, which makes it is difficult to achieve accurate frequency estimation in a short time. In this paper, a complex frequency domain interpolation DFT frequency estimation method based on rectangular window is proposed. Besides, the theoretical variance model of frequency estimator under the influence of noise is established, and the correctness of the variance model is verified by simulation. This algorithm considers the long-range leakage effect caused by the negative spectrum, so it still has a high frequency estimation accuracy when the length of the measurement window is less than 2 fundamental wave cycles. Simulation and experiments show that in the presence of noise and harmonics, even the measurement window is short, the frequency estimation performance of this algorithm is better than the existing frequency estimation algorithms.
Keywords: frequency measurement;Fourier transform;noise;harmonics
2024, 50(5):167-173 收稿日期: 2022-05-16;收到修改稿日期: 2022-07-27
基金项目: 国家电网公司科技项目资助（5216AG21000K）
作者简介: 王海元(1987-),男,湖北武汉市人,副高级工程师,主要从事电能计量采集,电力营销相关工作。
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