基于改进型自适应滤波器的正负序分解方法

针对分布式发电系统微电网并网的控制需求，文中介绍了一种三相电网电压信号正负序分量的提取方法，作为电网信号处理和同步的工具。基于多结构ANF的方法能够估计出电网信号的频率、振幅、基波及其正交分量等有用信息，利用基波及其正交分量信息能检测出电网中的正负序分量，但当电网信号的幅度或频率变化时，传统多结构ANF方法性能将降低。文中通过优化ANF的动态方程，提出一种改进的ANF结构，使其具有频率和幅值自适应性，并将改进后的多结构ANF用于电网信号正负序分量的提取。MATLAB仿真结果表明，该方案对电网信号中存在的电力系统干扰具有很高的抗干扰度，当三相电网信号不平衡时，其频率和幅度估计性能优于传统的多结构ANF正负序提取方法。

Positive and negative sequence decomposition method based on improved adaptive notch filter

In order to meet the control requirements of micro grid connection in distributed generation system, this paper introduces a method to extract the positive and negative sequence components of voltage signals in three-phase power grid as a tool for power grid signal processing and synchronization. The method based on multi structure ANF can estimate the useful information of frequency, amplitude, fundamental wave and its orthogonal component of power system signal. It also can detect the positive and negative sequence components of power system by using the information of fundamental wave and its orthogonal component, but when the amplitude or frequency of power system signal changes, the performance of traditional multi structure ANF method will be reduced. In this paper, by optimizing the dynamic equation of ANF, an improved ANF structure is proposed, which has self-adaptability of frequency and amplitude. The improved multi structure ANF is used to extract the positive and negative sequence components of power system signals. Matlab simulation results show that the scheme has a high degree of anti-interference to the power system interference in the power system signal. When the three-phase power system signal is unbalanced, its frequency and amplitude estimation performance is better than the traditional multi structure ANF positive and negative sequence extraction method.