基于SSI-LS的次同步谐振参数检测新方法

A New Method to Detect Parameters of Subsynchronous Resonance Based on SSI-LS

为精确检测出次同步谐振(SSR)参数,提出了基于随机子空间辨识(SSI)与最小二乘(Least Square)法的次同步谐振参数检测新方法。首先运用奇异值差值法确定次同步谐振模型信号的阶数;再利用SSI算法直接对量测信号精确检测出次同步谐振的频率;最后应用最小二乘法对各次同步频率分量进行幅值和相位的估计,从而实现了次同步谐振参数的检测。分别针对含有基波、高次谐波和次同步频率分量的信号以及含有噪声的上述信号进行参数检测,仿真分析表明该方法抗噪能力强、检测精度高、计算速度快,尤其是对频率相近的次同步频率信号具有较高的分辨率。

In order to detect accurately parameters of Subsynchronous Resonance（SSR）,a novel method based on Stochastic Subspace Identification（SSI） and Least Squares（LS） is proposed.The order number of SSR components is tested by using of singular value difference method at first.Then the actual frequency of each SSR in the original noisy signal is accurately detected by SSI algorithm.Finally,the method of least squares is applied to estimate the phase and amplitude of the SSR.The analysis on numerical simulation signal that includes fundamental,harmonic and SSR components shows that the method has strong anti-noise ability,high detection accuracy,rapid calculation,especially has high precision and resolution for detecting the phase of SSR signals with small variability,which provides a new way to detect precisely the SSR in power system.