DC converter station and its control method and control system

Abstract

The present invention provides a DC converter station and its control method and control system. The DC converter station control method includes controlling the sending-end converter station by using a constant DC voltage control method; controlling the receiving-end converter station by using an active-reactive power control method. flow station; wherein, wherein, the step of controlling the receiving end converter station using the active-reactive power control method includes: adding an input power adjustment module at the input end of the power loop of active-reactive power control, and the input power adjustment module is connected with the The power loop connection of the active-reactive power control; the input power adjustment module adjusts the input power command of the active-reactive power control according to the grid voltage of the receiving end and the DC bus voltage of the receiving end. With the present invention, reactive power can be continuously provided to the power grid when the voltage drops in the power grid at the receiving end, and no overcurrent phenomenon will occur in the converter station. DC bus voltage, the system can operate stably after the fault is restored.

Description

technical field [0001] The invention relates to the technical field of electric power transmission and distribution, in particular to a DC converter station and its control method and control system. Background technique [0002] With the continuous adjustment of my country's energy structure, flexible direct current transmission (HVDC), as a new type of power transmission method, is suitable for medium and long-distance transmission, especially in the The long-distance transmission of renewable energy and the interconnection of power grids have been widely used. [0003] Low-voltage ride-through (LVRT) capability means that when a voltage drop occurs at the grid-connected point, the grid-connected converter system can maintain the grid-connected state, and the system can resume normal operation after the power grid recovers. The low-voltage ride-through capability has been used as the grid-connected system at present. An important indicator has received extensive attention ...

AI Technical Summary

Problems solved by technology

[0003] Low-voltage ride-through (LVRT) capability means that when a voltage drop occurs at the grid-connected point, the grid-connected converter system can maintain the grid-connected state, and the system can resume normal operation after the power grid recovers. An important indicator has received extensive attention in engineering practice. Most of the research on LVRT in the academic circles focuses on the low-voltage ride-through capability of the receiving-end converter station system. However, when the voltage drops in the sending-end converter station, the failure of the HVDC system There are relatively few studies on the phenomenon and crossing control, and in-depth research is needed

Images