基于MODWT的自适应阈值微电网故障检测算法

对微电网线路故障的高效检测有助于快速切除故障,降低微电网对大电网的影响。现有的故障检测方法存在阈值难以选择、对高过渡电阻故障不敏感等问题,为此提出了基于极大重叠离散小波变换(MODWT)系数突变的自适应阈值选取故障检测算法。利用MODWT的特性,采用扩大窗的方法,在窗扩大的过程中对MODWT系数差值的阈值进行适应性调整。相较于现有的定阈值方法,该算法可以适应任意长度的数据样本对于多种故障状态可以进行适应性阈值调整,因此对高过渡电阻故障有较高的敏感度。通过仿真实验验证,该算法能在各种故障状态下快速检测故障发生的时间。

Adaptive Threshold Algorithm for Microgrid Fault Detection Based on MODWT

Efficient detection of microgrid line faults helps to quickly remove the fault and reduce the impact on the large power grid.Existing fault detection methods have problems such as difficulty in selecting thresholds and insensitivity to high transition resistance faults.The proposed adaptive threshold selection fault detection method based on sudden changes of MODWT coefficients uses the characteristics of MODWT and adopts the method of expanding the window to adaptively adjust the threshold of the MODWT coefficient difference during the process of window expansion.Compared with the existing threshold method,the method proposed can adapt to data samples of any length,and can adjust the adaptive threshold for various fault conditions,so it has a higher sensitivity to high transition resistance faults.Through simulation verification,this method can quickly detect the time of failure in various fault states.