Electric Power ›› 2022, Vol. 55 ›› Issue (12): 34-42.DOI: 10.11930/j.issn.1004-9649.202205007

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Open-Circuit Fault Diagnosis Method of Energy Storage Converter Based on MFCC Feature Set

YU Bin1, SONG Xingrong1, ZHOU Ting2, LUO Linbo3, LI Hui1, CHE Liang4   

  1. 1. Electric Power Research Institute of State Grid Hunan Electric Power Company Limited, Changsha 410007, China;
    2. State Grid Hunan Electric Power Company Limited, Changsha 410004, China;
    3. State Grid Loudi Power Supply Company, Loudi 417000, China;
    4. College of Electrical and Information Engineering, Hunan University, Changsha 410082, China
  • Received:2022-05-06 Revised:2022-10-20 Published:2022-12-28
  • Supported by:
    This work is supported by Science and Technology Project of SGCC (No.5216A521001K).

Abstract: Power conversion system (PCS) fault diagnosis plays an important role in the intelligent operation and maintenance of battery energy storage power stations. Considering the difficulties in signal feature extraction, data dimension explosion, and instability of threshold determination interval in the non-invasive identification of IGBT open-circuit fault in PCS by the existing methods, this paper proposes an open-circuit fault diagnosis method of energy storage converter based on Mel-scale frequency cepstral coefficients (MFCC) feature set, so as to support the normal operation and maintenance of PCS. Firstly, the three-phase current on the alternating current (AC) side is taken as the input signal, and an MFCC fault feature data set is constructed by analyzing the signal spectrum energy distribution and envelope characteristics in different frequency intervals. Then, through kernel principal component analysis (KPCA), the dimension reduction screening of nonlinear fault features under charge and discharge conditions is realized. Secondly, a fault state diagnosis model based on the Bayesian optimization algorithm (BOA) and one-dimensional convolutional neural network (CNN-1D) is constructed with a low-dimensional fault feature set as an input. Finally, through the fault simulation experiment of a grid-connected energy storage converter, the proposed method is compared with existing methods, and the results show that the proposed method has better robustness and accuracy in complex noise environments.

Key words: battery energy storage, converter, fault diagnosis, Mel-scale frequency cepstral coefficients, diagnosis model