基于参数分离降阶谐波提取方法

Reduced-order Harmonic Extraction Method Based on Parameter Separation

谐波的提取在工程应用中是一个重要的问题,往往涉及到复杂的参数估计运算,会影响到谐波提取的速度和精度。提出一种基于参数分离降阶谐波提取方法,将信号源分解为特定谐波和干扰谐波,并转换为与频率相关的参数化形式。利用子观测器估计未知向量,可分别计算出这两部分谐波。重复以上步骤,通过级联观测器,逐步降阶提取相应频率的谐波,最终得到期望的标准正弦信号。该方法利用辅助函数直接建立频率与谐波分量的联系,可以减少待估计参数,使得观测器性能易于分析调节。利用李雅普诺夫理论给出了该算法的稳定性条件,仿真结果验证了级联观测器的有效性。

The extraction of harmonics is an important topic in engineering applications, and involves complex estimation computation of parameters, which affects the extraction speed and accuracy. A reduced-order harmonic extraction method based on parameter separation is proposed in this paper. Firstly, the contaminated signal is decomposed into specific and disturbance harmonic components of frequency-dependent parametric forms. Then, the two unknown harmonic components can be calculated respectively by using sub-observer to estimate unknown vectors. Repeating the above steps, the harmonics of the corresponding frequency can be extracted gradually with reduced-order in framework of cascade observer. Resultantly, the desired standard sinusoidal signal can be obtained. This method establishes the relationship between frequency and harmonic components by using the auxiliary function, which reduces the parameters to be estimated. Thus, the performance of the proposed observer can be analyzed and regulated easily. The stability condition of the algorithm is given by Lyapunov theory and the simulation results verify the effectiveness of the cascade observer.