作者：舒骁骁¹, 祝君剑¹, 朱亮¹, 张军号², 温和²

作者单位：1. 国网江西省电力有限公司供电服务管理中心，江西 南昌 330077;
2. 湖南大学电气与信息工程学院，湖南 长沙 410082

关键词：迭代滤波;频率估计;抗噪性分析;方差估计

摘要：

电网频率是电力系统的关键参数，表征电网运行状态，对电力系统控制和保护至关重要。迭代滤波方法采用时域移频和迭代滤波两步可高效实现电网频率测量。然而，实际测量中，电力信号不可避免地受到噪声干扰而产生频率估计误差，影响频率测量准确度。因此，通过引入迭代滤波过程等效加权滤波器的等效噪声带宽、扇形损失参数以及滤波器重叠相关系数，研究加性高斯白噪声对基于迭代滤波的电力系统频率估计的影响，推导相应的方差表达式。通过设置不同的仿真参数，验证基于迭代滤波频率估计方差表达式的有效性。最后基于所推导的方差表达式，给出通过增加测量间隔和提高迭代次数提升实际测量中频率估计准确度的建议。

High accuracy iterative filtering frequency measurement method for power system based on noise effects
SHU Xiaoxiao¹, ZHU Junjian¹, ZHU Liang¹, ZHANG Junhao², WEN He²
1. Power Supply Service Management Center of Jiangxi Electric Power Co., Ltd., Nanchang 330077, China;
2. College of Electrical and Information Engineering, Hunan University, Changsha 410082, China
Abstract: Frequency is a key parameter of power system, which represents the state of power grid, and this makes it to be of great importance to control and protection of power system. The iterative filtering method has the merit of high efficiency for frequency analysis thanks to its simple implementation in the time domain. However, the inevitable white noise injected by various factors leads to inaccurate frequency estimation in practical measurement. This paper investigates the influence of the additive white Gaussian noise on FSF-based frequency estimation of the power system. The variance expression of the frequency estimator is derived theoretically by introducing the equivalent noise bandwidth, scalloping loss, and overlap correlation coefficient of the equivalent weighting filter in the iterative filtering process. The obtained results are validated by several computer simulations. According to the derived variance expression, the accuracy of frequency estimation in actual measurement can be improved by increasing the measurement interval and increasing the number of iterations.
Keywords: iterative filtering;frequency estimation;anti-noise analysis;variance estimation
2020, 46(7):54-59,132  收稿日期: 2020-06-12;收到修改稿日期: 2020-06-30
基金项目: 国家自然科学基金资助项目（61771190）
作者简介: 舒骁骁(1973-),女,江西南昌市人,高级经济师,硕士,主要从事电力谐波分析
参考文献
[1] 胡益, 王晓茹, 艾鹏, 等. 基于广域量测的交直流混联系统发生扰动后稳态频率预测算法[J]. 电力自动化设备, 2018, 38(11): 35-42
[2] 张恒旭, 李常刚, 刘玉田, 等. 电力系统动态频率分析与应用研究综述[J]. 电工技术学报, 2010, 25(11): 169-176
[3] 张政, 温和, 黎福海, 等. 多水平集单周期电力系统频率测量方法及应用[J]. 电工技术学报, 2017, 32(7): 119-127
[4] 王玉凤, 范必双, 王英健. 数字锁相环在电力系统谐波检测中的应用[J]. 电子技术应用, 2008(4): 51-52
[5] 王硕禾, 许继勇, 蔡清亮, 等. 联合三相锁相环和优化三点法的供电频率高精度测量算法[J]. 电力自动化设备, 2012, 32(1): 88-92
[6] 刘洁波, 黄纯, 江亚群, 等. 基于强跟踪泰勒-卡尔曼滤波器的动态相量估计算法[J]. 电工技术学报, 2018, 33(2): 433-441
[7] 李宁, 左培丽, 王新刚, 等. 基于改进DFT和时域准同步的间谐波检测算法[J]. 电力自动化设备, 2017, 37(4): 170-178
[8] 庞浩, 李东霞, 俎云霄, 等. 应用 FFT 进行电力系统谐波分析的改进算法[J]. 中国电机工程学报, 2003, 23(6): 50-54
[9] 吴铁洲, 张琪, 罗蒙, 等. 基于小波变换的自适应电网频率测量算法[J]. 武汉理工大学学报, 2016, 38(5): 86-91
[10] 李天云, 程思勇, 杨梅. 基于希尔伯特-黄变换的电力系统谐波分析[J]. 中国电机工程学报, 2008, 28(4): 109-113
[11] ROY S, DEBNATH S. ANN based method for power system harmonics estimation[C]//West Bengal: 2018 IEEE Applied Signal Processing Conference (ASPCON), 2018.
[12] 罗丹, 温和, 唐璐. 电网动态频率测量的移频迭代滤波方法及应用研究[J]. 电力自动化设备, 2019, 39(5): 151-156
[13] 李建闽, 滕召胜, 吴言, 等. 基于移频滤波的频率测量方法[J]. 中国电机工程学报, 2018, 38(3): 762-769
[14] BELEGA D, PETRI D. Effect of noise and harmonics on sine-wave frequency estimation by interpolated DFT algorithms based on few observed cycles[J]. Signal Processing, 2017, 140(11): 207-218
[15] 朱亮, 温和, 戴慧芳, 等. 计及噪声的动态谐波准同步采样分析方法[J]. 电力自动化设备, 2018, 38(2): 217-223
[16] WEN H, LI C, YAO W. Power system frequency estimation of sine-wave corrupted with noise by windowed three-point interpolated DFT[J]. IEEE Transactions on Smart Grid, 2018, 9(5): 5163-5172
[17] ROSCOE A J, BLAIR S M, DICKERSON B, et al. Dealing with front-end white noise on differentiated measurements such as frequency and ROCOF in power systems[J]. IEEE Transactions on Instrumentation & Measurement, 2018, 67(11): 2579-2591
[18] OFFELLI C, PETRI D. Weighting effect on the discrete time Fourier transform of noisy signals[J]. IEEE Transactions on Instrumentation & Measurement, 1991, 40(6): 972-981
[19] HARRIS, F. J. On the use of windows for harmonic analysis with the discrete Fourier transform[J]. Proceedings of the IEEE, 1978, 66(1): 51-83