Flexible direct current transmission system

Abstract

The invention provides a flexible direct current transmission system. The system comprises a transformer, a current converter and a coupling reactor, wherein the coupling reactor comprises an upper bridge arm coupling reactor and a lower bridge arm coupling reactor; the upper bridge arm coupling reactor and the lower bridge arm coupling reactor are connected through a connection of a same-polarityterminal and a different-polarity terminal; a connection point between the same-polarity terminal and the different-polarity terminal is a grid connection point; one end of the transformer is connected with an alternating-current power grid, and the other end is connected with the grid connection point; the current converter comprises three phase units; the phase units include an upper bridge armand a lower bridge arm; and the coupling reactor is connected between the upper bridge arm and the lower bridge arm.

Description

technical field [0001] The invention relates to the field of direct current transmission, in particular to a flexible direct current transmission system. Background technique [0002] With the depletion of fossil energy and the increasing pressure to improve the environment, China and the world are facing a strategic adjustment of energy structure, large-scale development and utilization of new energy is imperative. New energy sources such as wind power, solar energy, and tidal energy are intermittent and random. The large-scale consumption of new energy has become a major practical problem facing China's power system. Traditional power equipment, grid structure, and operation technology have become inadequate. In order to adapt to the profound changes in the future energy pattern, it is necessary to accelerate the research and development of new collection, transmission and consumption technologies to improve the utilization efficiency of new energy power generation. In re...

AI Technical Summary

Problems solved by technology

This method is used to suppress the short-circuit current of the second part, but the disadvantage of this method is that it makes the control method of the half-bridge modular multilevel converter more complicated and prolongs the The calculation time of the controller, when a fault occurs, there will be longer logic judgment and delay, which is not conducive to the safety of the half-bridge modular multi-level converter equipment

Since the influence of the first part of the short-circuit current is much higher than that of the second part, this method cannot suppress the first part of the short-circuit current

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