A transmission system that uses non-sinusoidal AC transmission to enhance the transmission capacity of urban power grids

Abstract

The invention provides a power transmission system that adopts non-sinusoidal AC power transmission to improve the transmission capacity of urban power grids. The system includes a first waveform conversion system and a third waveform conversion system for converting sinusoidal waves into alternating square waves. The second waveform conversion system and the fourth waveform conversion system converted into sine waves; the first waveform conversion system is connected to the second waveform conversion system through the first pole conductor and the second pole conductor, and the first pole conductor and the second pole conductor are connected to the second waveform conversion system. The polar wires are arranged in parallel; the third waveform conversion system is connected to the fourth waveform conversion system through the third polar wire. The power transmission system provided by the present invention utilizes the current bidirectional conduction capability of the voltage source converter, cooperates with the switch switching device, and solves the problem of the capacity increase and transformation of the AC line, and does not increase the short-circuit current level of the power grid, and has dynamic reactive power Transient functions such as compensation are of great significance to solve the contradiction between the increasing load of large cities and the increasingly difficult construction of new lines.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a power transmission system that adopts non-sinusoidal AC power transmission to improve the transmission capacity of urban power grids. 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 lan...

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 that adopts non-sinusoidal AC power transmission to improve the transmission capacity of the urban power grid. It solves the problem of AC line capacity expansion and transformation, and does not increase the short-circuit current level of the power grid, and has transient functions such as dynamic reactive power compensation, which is of great significance for solving the contradiction between the increasing load of large cities and the increasing difficulty of new lines

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