首先对一段正常工况下的历史数据进行离散小波分解,对不同尺度下的小波系数建立相应的NPE模型.经过多层小波分解,建立相应的统计量对过程进行监控-First discrete wavelet decomposition of some normal conditions of historical data, the NPE model wavelet coefficients in different scales. Multilayer wavelet decomposition, the es