A topology control method for DC power flow controller between three lines

Abstract

The invention provides a direct current power flow controller topological control method used among three lines, comprising the following steps of establishing a direct current power flow controller among three lines, connecting three power transmission lines through the direct current power flow controller, realizing a power flow regulation function of the three power transmission lines, whereinthe direct current power flow controller among three lines comprises a direct current power flow controller, a bypass switch and the like; and enabling the three direct current lines to be connected to the direct current bus of the same voltage source type converter, wherein the voltage source type converter is connected with a direct current power system and an alternating current power system for converting alternating current and direct current, the direct current power flow controller among three lines is equivalent to a voltage source connected in series among the three lines, so as to realize power transfer among three series voltage sources to further regulate the values of the three series voltage source voltages and to realize line power flow control. By virtue of the direct current power flow controller topological control method, power flow control of three lines is realized, and the power flow control dimensionality of the complex multi-end direct current power system is improved; and the direct current power flow controller topological control method has a symmetrical structure and is applicable to a power flow conversion occasion.

Description

technical field [0001] This application relates to the field of power electronic converters and direct current transmission, and in particular to a topology control method of a DC power flow controller between three lines, which is mainly used for DC power flow controller (DC Power Flow Controller, DCPFC for short) circuit topology design and operation control. Background technique [0002] With the rapid development and maturity of power electronic devices and modular multi-level technology, DC transmission has been widely used as an advanced technical means to realize large-scale renewable energy power generation grid connection and large-capacity long-distance sea / land new energy power transmission. attention, and will become a supporting technology for building a smart grid. The future DC transmission and distribution network has a complex topology, and the number of converter station nodes is usually smaller than the number of DC transmission branches, so there is a sho...

AI Technical Summary

Problems solved by technology

From the control effect of the inter-line DC power flow controller, the inter-line DC power flow controller can effectively control the power flow of one line, and the power flow of the other line changes passively, that is, a single inter-line DC power flow controller can only achieve a single target. DC power flow control

[0007] To sum up, the inter-line DC power flow controller proposed in the prior art can only realize the active increase / decrease of the power flow of one line and the passive decrease / increase of the other line power flow, and cannot actively control the flow of two lines at the same time. Power flow, which belongs to the degenerated 2-line power flow control mode, has limited application occasions, so there is currently a lack of new DC power flow controllers to achieve active control of 2-line power flow

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