A power transmission system based on mmc to improve the transmission capacity of AC overhead lines

Abstract

The invention provides a power transmission system for promoting alternating current overhead line transmission capacity based on an MMC. The power transmission system comprises a first voltage source converter, an interelectrode current transfer switch active module, an interelectrode current transfer switch passive module and a second voltage source converter. The input end of the first voltage source converter is connected to a first alternating current system, and the output end of the first voltage source converter is connected with the interelectrode current transfer switch active module. The interelectrode current transfer switch active module is connected with the interelectrode current transfer switch passive module through a first electrode wire, a second electrode wire and a third electrode wire. The interelectrode current transfer switch passive module is connected to a second alternating current system through the second voltage source converter. The good control performance of a modularization multi-level voltage source converter is utilized to match interelectrode current transfer switches, the problem of reformation of capacity expansion of alternating current circuits is well solved, the functions of dynamic reactive power compensation, harmonic governance and the like are achieved, and the power transmission system plays a significant role in solving the more serious contradiction between increasing loads and more difficulties in newly building of circuits.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a power transmission system for improving the transmission capacity of AC overhead lines based on MMC. Background technique [0002] In recent years, my country's urbanization has further accelerated, and urban electricity loads have continued to grow. Objectively, the scale and transmission capacity of the power grid are required to maintain continuous development. However, the following problems generally exist in urban power grids. [0003] The city's electricity load has increased, the transmission capacity of AC lines is insufficient, and the line corridors are scarce. For heavy-duty AC lines, it is impossible to greatly increase the transmission capacity by installing FACTS devices, and new lines encounter increasing resistance, especially for line projects into cities, which are difficult to get support in terms of land acquisition and environmental p...

AI Technical Summary

Problems solved by technology

[0009] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a power transmission system based on MMC to enhance the transmission capacity of AC overhead lines, which utilizes the good control performance of modular multi-level voltage source converters and cooperates with inter-pole current transfer switches. It solves the problem of capacity expansion and transformation of AC lines very well, and has functions such as dynamic reactive power compensation and harmonic control, which is of great significance to solve the contradiction between the increasing load and the increasingly difficult new lines

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