The invention relates to a detection method for micro faults in a
chemical process. The method comprises the following steps: normalization
processing is carried out on training data and then an LGPCA (local-global
principal component analysis) model is established, a local-global feature is extracted from the training data and serves as a
score vector, the mean value and the variance of the
score vector of the training data are calculated through a sliding window, a training KLD (
Kullback Leibler Divergence) component is obtained on the basis, further, main component space statistics T2 and
residual space statistics SPE are calculated based on the training KLD component, and a corresponding control limit is determined;
test data is collected, a corresponding main component vector and a residual vector are extracted by utilizing the LGPCA model, the mean value and the variance of the
test data score vector are calculated by utilizing the sliding window, an online KLD component is further obtained, the main component space statistics T2 and the
residual space statistics SPE are calculated on the basis of the online KLD component, and the control limit is used for monitoring. According to the method in the invention, the KLD is introduced into the traditional LGPCA method, the probability information contained in the
chemical process data can be fully utilized, and the micro
fault detection rate is improved.