Insulation Defects Identification of Power Transformers Using Artificial Neural Network Based Approach

摘要

This paper presents a novel approach based on an artificial neural network (ANN) for identifying the insulation defects of power transformers, which is so-called three-dimensional (3-D) partial discharge (PD) patterns recognition. First, four epoxy-resin power transformers with typical insulation defects are purposely made. These transformers will be used as the experimental models of PD examination. Then, to establish a database of PD patterns, a precious PD detector is used to measure the 3-D (φ-Q-N) PD signals of these experimental models in a shielded laboratory. The database is used as the training data to train a three-layer Back-propagation neural network (BPNN). In this work, a feature extraction method is adopted to reduce the number of dimensions of PD pattern. Moreover, a fast learning algorithm is used to speed up the training process. The training-accomplished BPNN can be a good insulation defects identification system for epoxy-resin power transformers. The proposed approach is successfully applied to practical epoxy-resin power transformers field experiments. Experimental results indicate that the proposed ANN-based approach is a powerful and accurate tool in terms of power transformers insulation defects identification. Moreover, the proposed approach has a good tolerance of noise interference.