Double 12-pulse valve bank coordinated-control method for ultra-high voltage direct-current transmission system

Abstract

The invention relates to a double 12-pulse valve bank coordinated-control method for an ultra-high voltage direct-current transmission system. The method is realized in a way that: two valve banks at each pole are connected in series, one ends are connected with each other, and the other ends are respectively connected to an polar high voltage bus and a polar neutral bus; the pole control system is divided into a dipole\pole control layer and a valve bank control layer, the valve bank control layer realizes trigger control on the high-voltage valve bank and the low-voltage valve bank, each valve bank control only collects the respective 12-pulse valve bank conversion flow bus voltage as the synchronous voltage of the trigger pulse, the trigger angle of the two 12-pulse valve banks in series can be adjusted to maintain the direct-current current and the direct current voltage, and the trigger angle between the valve banks in series can be coordinated and controlled to realize balanced operation of the valve banks in series; and the dipole\pole control layer generates a current command and simultaneously transmits the current command to high voltage and low voltage, i.e. master-slave valve bank control. The invention solves the problems of trigger angle deviation of high-voltage valve bank and low-voltage bank in series, and unbalanced voltage distribution caused by competitive control between valve banks in series, measuring errors and other factors.

Description

technical field [0001] The invention relates to a coordinated control method of double 12 pulsation valve groups in an extra-high voltage direct current transmission system and control system equipment using the method. Background technique [0002] The primary main wiring of the ±800kV UHV DC system is shown in Figure 1. It adopts the main wiring form of two 12-pulse valve groups in series for each pole, and the voltage of each valve group is 400kV. One end of the two valve groups is connected, and the other end is respectively connected to the extremely high pressure bus and the extremely neutral bus, which can be called the high pressure valve group and the low pressure valve group respectively. In actual operation, the two valve groups can be operated at the same time, or only the high-pressure valve group or the low-pressure valve group can be operated according to the needs. [0003] Each pole in a converter station is equipped with two sets of redundant pole control ...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is: according to the characteristics of the ±800kV direct current transmission project, a method for coordinated control of double 12 pulsation valve groups is proposed to solve the problem of high and low pressure series valve group trigger angles caused by factors such as competition control among series valve groups and measurement errors. Problems of deviation and unbalanced voltage distribution

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