毕业设计（论文）-基于MATLAB的航空故障电弧的仿真分析.doc

摘要
随着航空工业的发展,航空电气系统的复杂性逐渐提高,这使得对系统的可靠性有了更高的要求。因此,及时发现故障并采取相应的措施,尽量减小故障对飞机性能的影响,是提高飞机可靠性的重要条件。其中,故障电弧的存在就是影响航空电力设备稳定运行的一个潜在因素,所以检测故障电弧是必要的。
航空故障电弧作为一种低压故障电弧,具有一般故障电弧的特征,每半个周期都存在“电流零区”。但也具有自身的特殊性,即持续时间短、电流强度小、电弧波形复杂、电弧电源频率为400Hz等特点。从而使得以此为基础,来讨论电弧电流零点的检测情况。故障电弧的随机性,使得很难用传统的方法进行检测。长期以来,傅立叶变换是研究函数奇异性的主要工具,但是它缺乏空间局部性,只能确定函数奇异性的整体特性,不能确定奇异点在空间的位置和分布情况。而小波变换具有空间局部化性质,可利用它来分析信号的奇异性以及奇异性的位置和奇异度的大小。
本文首先利用航空故障电弧的电压电流波形,并对故障电弧基本特征经行了理论分析。然后选取合适的小波基函数,运用Matlab软件中的小波分析,将故障电弧电流信号分解,从分解后的数据中提取出特征参量。
关键词:航空;故障电弧;小波分析;MATLAB
Aviation arc fault simulation analysis based on MATLAB
Abstract
With the development of the aviation industry, aviation electrical system gradually plexly, which requires higher system reliability. Therefore, the timely detection of failures and corresponding measures to minimize the failure impact on the performance of the aircraft is an important condition for the aircraft to improve the reliability. And the existence of arc fault often effects the stable operation of air power equipment. Therefore, the arc fault detection is necessary.
AS a low-voltage arc fault, Air Arc Fault has the general characteristics of arc fault, and there are "current zero-area" in each half cycle. But it also has its own particularity, that is, short duration, current strength of the small, complex waveforms arc, arc power supply frequency of 400Hz and so on. It makes a basis to discuss the detection of zero arc current situation. However, Arc Fault’s randomness makes it difficult to use traditional methods for testing. As a long time, the Fourier transform function is the main tools to study the singularity, but for lacking of partial space, it can only determine the singularity of the overall nature of a function, not the location and distribution of the singular points in space. While, with the localized nature of space, Wavelet transform can be used to analyze the singularity of signal, as well as the location and the size of the singularity.
In this paper, it uses a