High-voltage high-power DC-DC conversion device

Abstract

The invention discloses a high-voltage high-power DC-DC conversion device comprising a cascade modular converter, a medium- and low-frequency sinusoidal three-phase transformer and an input parallel modular converter. The cascade modular converter comprises three bridge arms the same in structure. Each of the upper and lower half bridge arm of each bridge arm comprises at least two half-bridge topology power modules and a reactor, wherein the power modules and the reactor are connected in series. The input end of the medium- and low-frequency sinusoidal three-phase transformer is respectively connected to contacts of the three bridge arms. The input parallel modular converter comprises a modular converter submodule or at least two mutually parallel modular converter submodules, and the input end of every modular converter submodule is connected to the output end of the medium- and low-frequency sinusoidal three-phase transformer. The high-voltage high-power DC-DC conversion device has the advantages that the problems of voltage withstanding, voltage sharing and insufficient transmission capacity in existing high-voltage side switching devices are solved well; the high-voltage high-power DC-DC conversion device is also significant to quickening the utilization and marketization process of high-voltage DC-DC conversion devices.

Description

technical field [0001] The invention relates to a high-voltage DC-DC power conversion and transmission device, in particular to a high-voltage and high-power DC-DC conversion device. Background technique [0002] High-voltage direct current transmission (HVDC) has the characteristics of large transmission power capacity, low loss, long transmission distance, and good stability, and has broad application prospects. In order to adapt to the direct application of high-voltage direct current transmission to electrical equipment in the future, it is necessary to have a DC transformer device with a function similar to that of an AC isolation transformer to convert high-voltage direct current into isolated low-voltage direct current that meets the requirements of electrical equipment. [0003] Since the withstand voltage of a single power semiconductor device is usually limited, a single power semiconductor device cannot be directly applied to high-voltage applications. In order t...

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Problems solved by technology

[0008] The purpose of the present invention is to provide a high-voltage and high-power DC-DC conversion device, which skillfully utilizes the existing power module series connection technology and low- and medium-frequency sine wave three-phase transformers, and solves the current high-voltage DC-DC conversion problem very well. The problems of withstand voltage and voltage equalization of switching devices on the high-voltage side of DC converters and the problem of insufficient transmission capacity of existing DC-DC converters are of great significance for accelerating the practical and marketization of high-voltage DC-DC converters.

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