基于小波变换的整流装置故障特征提取

在对某型号飞机电源系统整流装置进行故障模式分析的基础上,通过对各故障模式下整流装置输出电压的实测信号样本的频谱分析,获得对故障敏感的特征频率点,根据小波变换的多分辨率分析理论,确定了与特征频率点相对应的小波母函数和变换尺度.在此基础上,通过定义"频带能量特征向量",将小波变换得到的小波系数转换为一组特征向量,作为故障检测的依据.实测样本信号的分析结果表明,该方法克服了传统傅里叶分析的固有缺陷,得到的故障特征向量符合灵敏性、鲁棒性的要求,可有效区分各故障模式.

Fault characters of the rectifier based on wavelet theory

Based on the fault pattern analysis of the rectifier in aircraft power system, through the frequency analysis of output voltage in every fault pattern, the key points on frequency to each fault pattern were gained. According to multi-resolution analysis in wavelet theory, the basic wavelet function and scale corresponding to key points was confirmed. By defining 'frequency energy character vector', the wavelet coefficient was converted to a character vector as the criterion in fault diagnosis. Results for measured sample show that this method conquered the inherit shortage of traditional Fourier analysis. The obtained fault character vector is of quite quality in sensitivity and robustness, and is capable of distinguish diversified fault modes.