一种由间谐波估计电压闪变参数的简便方法  

A simple method of voltage flicker estimation based on interharmonics

作　　者：李霏霏[1,2] 杨洪耕[1,2] 惠锦[1,2] 叶茂清[3] 

机构地区：[1]四川大学电气信息学院,四川成都610065 [2]智能电网四川省重点实验室,四川成都610065 [3]四川电力科学研究院,四川成都610072

出　　处：《电力系统保护与控制》2011年第22期83-89,共7页Power System Protection and Control

基　　金：国家自然科学基金资助项目(51077095)~~

摘　　要：提出一种基于离散插值傅里叶变换估计电压闪变的新方法,在检测间谐波的同时估计出闪变参数。该方法以IEC61000-4-7推荐的测量环境为前提,用一种非同步采样下的奇数频点插值修正方法检测畸变信号中各分量的频率、幅值和相位,能够在插值的同时抑制旁瓣泄漏;由电压闪变公式通过三角函数变换得到调幅波-间谐波对的双边带特性;考虑电压闪变最大觉察频率范围,确定间谐波对频率阈值;基于电力畸变分量共生机理,区分调幅波-间谐波对和一般间谐波分量,通过正弦载波的幅度调制求得电压闪变信号的参数。仿真算例与平方法和Prony法比较,证明了该方法的准确性和有效性。仿真结果表明用该方法完成间谐波与闪变参数及其评价指标的估计是可行的;奇数频点插值修正方法能够有效地分离信号中的谐波和间谐波成分、抑制它们之间的频谱干扰。This paper proposes a new method to estimate voltage flicker using the discrete Fourier transform, which obtains the parameters of voltage flicker while estimating interharmonics. The proposed method obtains the amplitude, frequency and phase angle of each frequency component using the odd points interpolation correction method, which reduces the leakage while interpolating, based on the specified signal processing recommendations by IEC61000-4-7. According to the concept of voltage flicker, the double-side property of interharmonic pairs converted by voltage flicker is obtained. Considering the maximum perceptible frequency range of the voltage flicker, the frequency range of interharmonics pairs can be obtained. According to the electric power distortion component symbiosis mechanism, we can differentiate the interharmonic pairs from the common interharmonic components, and obtain the parameters of flicker signal by the amplitude modulation with sinusoidal carrier. Comparing with the Square method and Prony method, the simulation results indicate the accuracy and validity of the proposed method, and the odd points interpolation correction method can separate harmonics from interharmonics effectively and restrain the spectral interruption strongly.

关 键 词：电能质量 闪变 间谐波 频谱分析 离散傅里叶变换 

分 类 号：TM711[电气工程—电力系统及自动化]