Flexible DC transmission bipolar main junction device

Abstract

The invention relates to a flexible DC transmission bipolar main junction device which comprises two converter stations, two AC power systems and a metal wire. The two converter stations are of the same structure and are each formed by sequentially connecting a first transformer, a first converter device, a second converter device and a second transformer in series, wherein the first transformer and the second transformer are connected to one ends of buses in parallel respectively, and the other ends of the buses are connected with the AC power systems; the first converter device of the first converter station is connected with the first converter device of the second converter station through a straight cable, the second converter device of the first converter station is connected with the second converter device of the second converter station through a straight cable, one end of the metal wire is connected to the line between the first converter device and the second converter device of the first converter station, and the other end of the metal wire is connected to the line between the first converter device and the second converter device of the second converter station. The flexible DC transmission bipolar main junction device is safe in layout and reliable in running and can be widely applied to the field of flexible DC transmission.

Description

technical field [0001] The invention relates to the field of flexible direct current transmission, in particular to a bipolar main connection device for flexible direct current transmission. Background technique [0002] Flexible direct current transmission is a new type of direct current transmission technology other than traditional high voltage direct current transmission technology. ) for AC-DC conversion, while the traditional high-voltage DC power transmission technology uses semi-controlled (self-conducting but not self-off) semiconductor devices (such as thyristors) for AC-DC conversion, which needs to rely on the external voltage provided by the AC power system Assist to turn off the thyristor to ensure the normal operation of AC-DC conversion. The common point of the flexible DC transmission technology and the traditional DC transmission technology is that both are equipped with positive and negative poles (pole I is the positive pole, and pole II is the negative ...

AI Technical Summary

Problems solved by technology

As the transmission capacity of the flexible DC transmission project increases, its rated current also increases correspondingly, reaching several thousand amperes, and the unbalanced current into the ground will also increase. The simple grounding system of the converter stations at both ends cannot meet the requirements. The operation requirements of large unbalanced current into the ground, and the large current will affect the industrial facilities (such as metal pipelines, power facilities) between the converter stations at both ends

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