Power grid transmission capacity-increasing transformation method based on double MMC current converters

Abstract

The invention provides a power grid transmission capacity-increasing transformation method based on double MMC current converters, comprising the steps of: establishing a voltage source current converter and a voltage current regulator, wherein the voltage source current converter comprises a sending end voltage source current converter and a receiving end voltage source current converter, and the voltage current regulator comprises a sending end voltage current regulator and a receiving end voltage current regulator; connecting the sending end voltage source current converter between a sending end alternating current system and the sending end voltage current regulator, and connecting the receiving end voltage source current converter between a receiving end alternating current system and the receiving end voltage current regulator; and connecting the sending end voltage current regulator with the receiving end voltage current regulator through alternating current cables. Compared with the prior art, the power grid transmission capacity-increasing transformation method based on the double MMC current converters provided by the invention has the advantages of dynamic reactive power compensation, harmonic suppression and the like, and has significant meaning in solving contradiction of increasing load and increasing difficulty in building new circuits.

Description

technical field [0001] The invention relates to the field of power transmission systems, in particular to a method for improving the capacity of power grid transmission based on double MMC converters. Background technique [0002] In recent years, the speed of urbanization has been further accelerated, and the urban electricity load has continued to increase. 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 protection....

AI Technical Summary

Problems solved by technology

However, the space charge accumulation of AC cable lines is serious under DC conditions, and the electric field strength in the insulation can increase to 7 to 9 times the initial value after long-term pressurization

However, the space charge problem was not considered in the development of the actual AC cable, so after the AC cable line is converted to DC operation, the space charge will cause electric field distortion, and in severe cases, it will cause breakdown of the cable insulation.

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