电压暂降扰动源电压空间矢量辨识法

摘要:

分析了不同暂降扰动源产生的电压暂降的幅值、相位和谐波特征，提出一种基于电压空间矢量的电压暂降扰 动源辨识方法。该方法先对三相电压信号进行αβ 变换构造出电压空间矢量和零序分量，利用离散傅里叶变换( DFT) 将电压空间矢量分解成正、负序两个旋转分量，构造出幅值、相位和谐波特征量，将三者相结合可对造成电压暂降的 扰动源进行辨识。时变电压空间矢量在复平面轨迹的三维可视化的描述可以对电压暂降全过程进行全面表征。利 用Matlab /Simulink 建立简单配电网的仿真模型，结果验证了所提出方法的有效性和正确性。

Abstract:

On the basis of analyzing the features of various voltage sags due to short － circuit faults，transformer energizing and induction motor starting in power system，a new method to identify voltage sag sources based on voltage space vector ( VSV) is proposed． In the proposed method，αβ transform is applied to three － phase voltage to get the voltage space vector and zero － sequence components at first． Then，the discrete Fourier transform ( DFT) is applied to the VSV to get characteristics of amplitude，phase and the harmonic，which can be used to identify voltage sag sources． The 3d visualization of the time － varying VSV in complex plane could clarify the global voltage sag evolution along the time． The results of simulation using Matlab / Simulink show this method is simple and accurate．