摘要
为精确检测谐波和间谐波的三参数,提出了基于随机子空间辨识(Stochastic Subspace Identification,SSI)与最小二乘(Least Square)法的谐波和间谐波三参数检测方法。运用奇异值差值法确定SSI-LS算法的阶数;利用SSI算法直接对原始含噪信号精确检测出各谐波和间谐波分量的频率;当信噪比大于20dB时,应用最小二乘法对各谐波和间谐波分量进行幅值和相位的估计,从而实现了谐波和间谐波的三参数识别。分别针对含有噪声和直流分量的谐波和间谐波数值仿真信号和频率相近且幅值相差百倍的谐波和间谐波信号作谐波和间谐波的三参数识别。仿真分析表明该方法抗噪声能力强、检测精度高、计算速度快,尤其是对信号中各谐波和间谐波分量的相位检测精度高、对频率相近且幅值相差百倍的谐波和间谐波信号具有较高的分辨率,为电力系统谐波和间谐波的精确检测提供了新的思路与方法。
In order to detect accurately three parameters of harmonic and inter-harmonic,a method of three parameters of harmonics and inter-harmonic detection based on Stochastic Subspace Identification（SSI）and least squares（LS）is proposed.The order of SSI-LS algorithm is tested by use of the singular value difference method,and the actual frequency of each harmonic and inter-harmonic component in the original noisy signal is accurately detected by SSI algorithm,and the method of least squares is applied to estimate the phase and amplitude of the harmonic and inter-harmonics component when SNR is more than 20 dB.So three parameters of inter-harmonics are identified completely. The numerical simulation signals with noise and DC component and the signals with similar frequency and hundredfold-difference amplitude are identified by using three parameters of harmonic and inter harmonic detection. Simulation analysis shows that the method has strong anti-noise ability, high detection accuracy and fast calculation speed, especially has high precision and resolution for the phase of inter-harmonic signal with similar frequency and hundredfold-difference amplitude.It provides a new method for the harmonic precision detection in power system.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2011年第10期42-46,共5页
Power System Protection and Control
基金
国家自然科学基金项目(No.50777007)~~
关键词
谐波
间谐波
奇异值差值法
随机子空间
最小二乘法
harmonic
inter-harmonic
singular value difference
stochastic subspace identification
least squares
