基于矩阵束和奇异值分解的间谐波检测算法

Interharmonic detection algorithm based on a matrix pencil and singular value decomposition

目前,电力系统中频率邻近的间谐波和含有暂态扰动的信号中的间谐波难以准确检测。针对上述两类间谐波成分,首先,采用矩阵束算法在噪声情况下对含有邻近间谐波的稳态信号进行检测。其次,对于含有暂态扰动的信号中的间谐波,提出了奇异值分解(SVD)和矩阵束算法相结合的检测方法。该方法运用SVD精准定位信号发生突变的时刻,将含暂态扰动的信号分解为多段平稳信号后利用矩阵束算法计算模态参数。通过对Matlab仿真数据和风机次同步振荡仿真信号的检测对上述方法的准确性进行了验证。进一步检测了某风电场双馈风机输出功率变化时定子电流中的谐波、间谐波参数,其结果与理论分析相符合,具有较强的实用性。

At present,it is difficult to accurately detect interharmonics at an adjacent frequency and in signals with transient disturbances in a power system.For the above two types of interharmonic components,first,a matrix pencil algorithm is used to detect the steady-state signal with adjacent interharmonics in noise.Secondly,for the interharmonics in the transient disturbances signal,the Singular Value Decomposition(SVD)and matrix beam algorithm combined detection method is proposed.This uses SVD to accurately locate the moment when the signal is abrupt,decomposes the transient disturbance signal into multi-segment stationary signals and then uses the matrix pencil algorithm to calculate the modal parameters.The accuracy of the above method is verified by the detection of Matlab simulation data and the sub-synchronous oscillation simulation signal of the fan.The method is used to detect the harmonics and interharmonics in the stator current when the output power of a wind farm double-fed fan is changed.The results are consistent with the theoretical analysis and the methods have strong practicability.