Zhejiang University

Xueqi Liu

Xin Zhang

Hao Ma

Fanfan Lin

Yuankui Wang

Disclosed is a fault diagnosis method for a four-switch Buck-Boost converter, including the following steps: obtaining circuit parameters when different faults occur, labeling fault parameters with fault types, and combining the fault parameters and labels into a data set; constructing a simplified self-organizing neural network consisting of a plurality of nonlinear operation modules, a weighting module, and an analysis module; performing training by using the data set to obtain a self-organizing neural network for determining the faults of the converter; and inputting the circuit parameters of the four-switch Buck-Boost converter to the self-organizing neural network, so as to determine the fault types of the four-switch Buck-Boost converter. Further disclosed is a fault diagnosis apparatus for a four-switch Buck-Boost converter. The method provided by the present invention is capable of simultaneously identifying and locating the faults of the four-switch Buck-Boost converter, such as an open circuit fault of a switching tube, aging of a capacitor, and aging of an inductor, and has good diagnosis accuracy and generalization capability.

Fault diagnosis method and apparatus for four-switch buck-boost converter

Disclosed in the present invention is a graph theory-based method for locating an instability fault source in a direct-current microgrid. The method includes: collecting key electrical feature quantities through an instability fault feature collection and extraction link to accurately capture an instability oscillation phenomenon, and utilizing wavelet packet decomposition to construct fault feature vectors; then, according to the structure of the direct-current microgrid, constructing an undirected graph model G=(V, E, X), which lays a foundation for analysis; applying a graph convolutional neural network for deep learning and training to further improve the accuracy and efficiency of diagnosis; deploying the trained model in an actual system to effectively achieve accurate fault diagnosis and location of an instability source. Also provided in the present invention is a device for locating an instability fault source in a direct-current microgrid. The method provided by the present invention can significantly improve a maintenance level of the direct-current distribution network, and greatly improve a detection and adjustment ability of system operation stability through advanced automatic diagnosis technology.

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HANGZHOU, China

Xueqi Liu