基于特征余弦差分的微电网故障诊断研究

Research on Fault Diagnosis of Microgrid based on Characteristic Cosine Difference

摘要:

针对微电网线路故障诊断问题,本文通过电流和电压故障分量求解椭圆方程参数来提取故障特征,利用椭圆方程和最小二乘法获取特征余弦来描述电压和电流的联合行为。使用5个采样点来确定用于获取总线电压和电流之间极性关系的椭圆参数。分析微电网的结构和使用特征余弦,讨论故障发生在不同位置时特征余弦的变化。采用±1定义总线的特征方向,结合特征余弦得到差分特征方向来检测故障区段位置,避免不同微电网运行方式的阈值选择。

Abstract:

To solve the problem of micro grid line fault diagnosis, this paper uses current and voltage fault components to solve elliptic equation parameters to extract fault features, and uses elliptic equation and least square method to obtain characteristic cosine to describe the joint behavior of voltage and current. Five sampling points are used to determine the ellipse parameters used to obtain the polarity relationship between bus voltage and current. The structure and characteristic cosine of microgrid are analyzed, and the change of characteristic cosine when the fault occurs in different position is discussed. The bus characteristic direction is defined by ± 1, and the differential characteristic direction is obtained by combining the characteristic cosine to detect the fault section position, so as to avoid the threshold selection of different microgrid operation modes.