Zhejiang University

Hangzhou Hikvision Digital Technology Co., Ltd.

Zhongce Rubber Group Co., Ltd

Xin Zhang

Jie Chen

Jing Li

Yaodong Lin

Xueqi Liu

Hao Ma

Bei Liu

Yongfeng Liu

Daliang Guo

Huifang Zhao

Hongge Pan

Mingxia Gao

Yahui Meng

Weiyan Zhang

Yuankui Wang

Lizheng Sha

Fanfan Lin

Jiafeng Lv

Yinchao Xu

Tianzhong Yuan

Ziyang Chang

Qianyu Sun

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.

Graph theory-based method and device for locating instability fault source in direct-current microgrid

Vehicle tyre

Disclosed is a preparation method of double-layer carbon-paper base paper with high uniformity and gradient pores, including adding carbon fibers to alkali lignin aqueous solution for treatment, controlling the alkali lignin aqueous solution to reach subcritical water conditions, and modifying the carbon fibers by sodium phenol reactive groups under the subcritical water conditions of the alkali lignin, for improving hydrophilic groups on a surface of the carbon fibers and a surface rough structure; further, modifying the carbon fibers to produce carbon nanotube clusters on the surface of the carbon fibers to obtain surface-thermally-modified carbon fibers, and adding the surface-thermally-modified carbon fibers to a dispersant for dispersion, stirring together with auxiliary materials to prepare a mixed slurry, and preparing the mixed slurry into the carbon-paper base paper by wet forming process.

Preparation method of double-layer carbon-paper base paper with high uniformity and gradient pores

The invention discloses nano magnesium hydride and an in-situ preparation method thereof, including disposing and stirring magnesium chloride and lithium hydride in an organic solvent under a protection of an inert atmosphere, so as to obtain an organic suspension of a mixture; performing an ultrasonic treatment to the organic suspension, so as to promote a chemical reaction of the mixture. After the reaction is completed, the suspension is filtered; the solid reaction product is washed, centrifuged and dried to remove residual organic matter, so as to obtain nano-magnesium hydride.

Nano magnesium hydride and in-situ preparation method thereof

The present application discloses a method and apparatus for generating a panoramic image. A cuboid three-dimensional image of each local space is determined according to an original two-dimensional image of each local space in the overall space and a preset cuboid model corresponding to each local space, and then a three-dimensional panoramic image of the overall space is generated according to all determined cuboid three-dimensional images. Since the three-dimensional panoramic image of the overall space is generated according to the cuboid three-dimensional images of all local spaces, the overall space may be visually viewed at a three-dimensional angle of view to achieve the three-dimensional real-scene effect.

Panoramic image generating method and apparatus

Provided are a method and apparatus for fusion of a panoramic video to solve a problem that a panoramic video image formed by stitching is incomplete. The method includes: acquiring a panoramic video image (); extracting a moving target from at least two cuboid three-dimensional images (); performing image fusion processing on the panoramic video image and the moving target to form a panoramic video image incorporated with the moving target (). Thereby, problems such as overlapping and disappearance of a moving target, in whole or in part, in a panoramic video image generated by adopting a cuboid three-dimensional model are solved, thereby ensuring the completeness of a panoramic video image and improving the quality of the panoramic video image.

Method and device for fusing panoramic video images

Growing community of inventors

Hangzhou, China

Xin Zhang