Modular five-level current converter fault locating method based on depth convolution network

Abstract

The invention discloses a modular five-level current converter fault locating method based on a depth convolution network, and the method comprises the steps: combining capacitor voltage signals collected by submodules of a modular five-level current converter into a multi-channel sequence; carrying out the sampling of the multi-channel sequence, obtaining a data tape and carrying out the normalization processing, wherein the processed data tape is taken as a gray-scale map and serves as the input of a depth convolution network model; extracting the features of data through a plurality of intersected convolution layers and ponding layers in the depth convolution network model, transmitting a characteristic pattern of the last ponding layer to a full-connection layer for fusion, and achieving the fault classification through a softmax classifier, wherein different types are corresponding to fault submodules at different positions, thereby achieving the detection and position of a fault. According to the invention, the data needed by the method is easy to obtain, and there is no need of an additional sensor, thereby greatly reducing the cost. Moreover, the method is stronger in capabilities of MMC fault recognition and location.

Description

technical field [0001] The invention relates to the field of converter fault location, in particular to a method for fault location of a modular five-level converter based on a deep convolutional network. Background technique [0002] The flexible DC transmission system uses IGBT turn-off devices and high-frequency modulation technology, which overcomes many inherent defects of traditional DC transmission. The core part of the flexible DC transmission system is the converter at both ends of it, which plays the role of rectification and inverter. In the flexible DC transmission system that is actually put into engineering application, there are mainly three types of converters, namely two-level converters, three-level converters and modular multilevel converters (Modular Multilevel Converter, MMC), compared with the previous two converters, the modular multilevel converter can achieve different voltage and power requirements by changing the number of sub-modules in the circui...

AI Technical Summary

Problems solved by technology

Short-circuit faults are more destructive, so the sub-module drive circuit is generally equipped with a short-circuit protection module. When a short-circuit fault occurs, the sub-module is blocked locally to ensure that the system can still operate normally; although the open-circuit fault is relatively less harmful, it is not easy It is detected immediately, resulting in consequences such as voltage and current waveform distortion, threatening the normal operation of the system

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