An Intelligent Fault Diagnosis Method for Imbalanced Nuclear Power Plant Data Based on Generative Adversarial Networks

In the fault diagnosis problem, where sample data of fault cases are imbalanced, data generation and expansion are performed based on a generative adversarial network to obtain balanced data for training. Combining a gated recurrent neural network and an autoencoder model, the GRU-BEGAN model for generating multiple time series data is proposed for the intelligent fault diagnosis of imbalanced nuclear power plant data. To guarantee the consistency of the probability distribution between the generated data and real data, the K-L losses are included as a part of the loss function of the generator. At the same time, the potential feature vector of the real data obtained by the discriminator encoder is introduced as a hidden variable in the generator, and the similarity between the generated data and the real data is controlled by introducing the hidden variables according to the probability to make the generated data diverse. For the imbalanced fault dataset of the nuclear power plant thermal–hydraulic systems, the proposed GRU-BEGAN model is used to expand the original data to obtain a balanced state. Then, a 1D-CNN fault diagnosis model is established based on a convolutional neural network. The experimental results show that the fault diagnosis accuracy of the total test data is improved by 1.45% after data expansion, and the fault diagnosis accuracy of the minority sample is improved by 6.8% after data expansion.