| 引用本文: | 许苏迪,袁宇波,李娟,杨雄,姜云龙,汪家铭.基于加窗DFT滤波特性的电网宽频信号高精度测量方法[J].电力自动化设备,2025,45(7):204-211 |
| XU Sudi,YUAN Yubo,LI Juan,YANG Xiong,JIANG Yunlong,WANG Jiaming.High-accuracy measurement method for wide-frequency signals in power grid based on filtering characteristics of windowed DFT[J].Electric Power Automation Equipment,2025,45(7):204-211 |
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| 摘要: |
| 高比例新能源和高比例电力电子设备使电力系统中宽频振荡频发，对宽频信号进行监测可为振荡的机理分析和抑制提供数据支撑。提出了一种基于加窗离散傅里叶变换(DFT)滤波特性的电网宽频信号高精度测量方法。该方法分析了加窗DFT的带通滤波特性，基于其幅频特性和相频特性揭示了宽频信号参数测量的误差机理；构建了窗系数正、负频段的增益比与频率偏差的一一映射关系，基于此推导了宽频信号参数的误差修正模型，进一步提出了基于插值拟合窗系数滤波特性的实用化宽频信号参数高精度测量方法。仿真和现场录波数据测试表明，所提方法可在较短时间窗内实现宽频信号的精确测量，可用于实际系统中监测宽频振荡。 |
| 关键词: 宽频振荡 宽频信号 谐波测量 间谐波测量 加窗离散傅里叶变换 |
| DOI：10.16081/j.epae.202504012 |
| 分类号:TM93 |
| 基金项目:国网江苏省电力有限公司科技项目(J2023144) |
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| High-accuracy measurement method for wide-frequency signals in power grid based on filtering characteristics of windowed DFT |
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XU Sudi, YUAN Yubo, LI Juan, YANG Xiong, JIANG Yunlong, WANG Jiaming
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Electric Power Research Institute of State Grid Jiangsu Electric Power Co.,Ltd.,Nanjing 211103, China
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| Abstract: |
| High proportion of new energy and high proportion of power electronic equipment lead to frequent wide-frequency oscillation in the power system. Monitoring wide-frequency signals can provide data support for the mechanism analysis and suppression of oscillation. A high-accuracy measurement method for wide-frequency signals in power grid based on the filtering characteristics of windowed discrete Fourier transform(DFT) is proposed. The band-pass filtering characteristics of windowed DFT are analyzed and the measurement error mechanism of wide-frequency signal parameters is revealed based on amplitude-frequency characteristics and phase-frequency characteristics of windowed DFT. Then, the one-to-one mapping relationship between the frequency deviation and gain ratio of positive and negative frequency bands of window coefficients is constructed. Based on this, error correction models for wide-frequency signal parameters are derived, and a practical high-accuracy measurement method for wide-frequency signal parameters based on the interpolation-fitted filtering characteristics of window coefficients is further proposed. Simulation and field recorded data tests show that the proposed method can achieve accurate measurement of wide-frequency signals in a short time window, and can be further used for monitoring wide-frequency oscillation in actual power systems. |
| Key words: wide-frequency oscillation wide-frequency signal harmonic measurement interharmonic measurement windowed DFT |
