Coordinated optimization control method for multi-infeed DC auxiliary power/frequency combination controller

Abstract

The invention provides a multi-infeed direct-current auxiliary power / frequency combination controller coordination optimization control method, which comprises the following steps of: establishing a mathematical model of a multi-infeed direct-current power transmission system according to a connection relationship of the multi-infeed direct-current power transmission system; solving a multi-infeedinteraction factor, a multi-infeed effective short-circuit ratio and a multi-infeed power support factor of the multi-infeed direct-current power transmission system in a mode of applying small disturbance; determining the final DC power boosting amount of each loop; judging the tie line fault by measuring whether the power of the tie line is suddenly reduced to 0 or not; obtaining a multi-infeeddirect-current auxiliary power / frequency combined controller structure by adopting an active power large-mode controller and a bilateral frequency difference controller structure. The multi-infeed effective short-circuit ratio proportionality coefficient and the multi-infeed power support factor proportionality coefficient are adopted to perform emergency control on an internal fault of the alternating current system and a tie line fault disturbance form, so that coordination and optimization of emergency control of the multi-infeed direct current interconnected power system are realized, andthe transient stability of the system is improved.

Description

technical field [0001] The present invention relates to the technical field of multi-infeed direct current additional control, in particular to a multi-infeed direct current auxiliary power / frequency combined controller coordinated optimization control method. Background technique [0002] High-voltage direct current transmission (HVDC) can realize long-distance and large-capacity transmission of electric energy, and is an important means of interconnecting large power grids. For the AC-DC interconnected grid, using the DC overload capability and fast adjustment characteristics to realize emergency control after grid disturbance can significantly improve the transient stability of the interconnected grid. According to different emergency control purposes, it can be divided into: 1) emergency power control; 2) auxiliary frequency control; 3) additional damping control. Although the purposes of emergency control are different, they are all realized by changing the DC transmis...

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Problems solved by technology

[0004] Aiming at the technical problem that the existing DC power control does not distinguish between the internal fault disturbance of the AC system and the fault disturbance of the tie line, but adopts the same control strategy, and cannot realize dynamic optimal control, the present invention proposes a multi-feed DC auxiliary power / frequency combination Based on the controller coordination optimization control method, a multi-circuit DC auxiliary emergency power / frequency combination controller is designed for two kinds of power disturbances, the internal fault disturbance of the AC system and the tie line fault disturbance. Coordinated optimization of multi-circuit DC auxiliary emergency power / frequency controllers based on proportional coefficient of input power support factor

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