Coordinated control method and device for synchronous phase modifier and LCC-HVDC (line-commutated-converter high voltage direct current)

Abstract

The invention provides a coordinated control method and device for a synchronous phase modifier and LCC-HVDC (line-commutated-converter high voltage direct current). According to the coordinated control method and device, a fault judgment module is used to judge whether a fault occurs in an alternating current system, if the fault occurs in the alternating current system, turn-off angle deviationis calculated according to the turn-off angle of the LCC-HVDC; voltage deviation is determined according to the turn-off angle deviation, and the control input quantity of the synchronous phase modifier is calculated according to the voltage deviation; the excitation voltage of the synchronous phase modifier is determined according to the control input quantity of the synchronous phase modifier; and the coordinated control of the synchronous phase modifier and the LCC-HVDC is realized according to the excitation voltage of the synchronous phase modifier; and the capacity of the LCC-HVDC to resist commutation failures can be improved through the coordinated control of the synchronous phase modifier and LCC-HVDC. With the coordinated control method and device of the invention adopted, the capacity of the LCC-HVDC to resist commutation failures can be improved by means of the capability of the reactive power of the synchronous phase modifier to stabilize the voltage of a bus-bar, and theprobability of the commutation failure of the LCC HVDC can be decreased.

Description

technical field [0001] The invention relates to the technical field of direct current transmission, in particular to a method and device for coordinated control between a synchronous condenser and an LCC-HVDC. Background technique [0002] Due to the significant development in the field of power electronics technology in recent years, line-commutated-converter high voltage direct current (LCC-HVDC) has attracted more and more attention. With its advantages in long-distance large-capacity power transmission, cross-strait power transmission, and interconnection of AC systems, it has been widely used around the world. However, since conventional DC transmission systems use thyristors without self-shutoff capability as commutation components, a certain strength of AC system is required to provide commutation voltage, which is prone to commutation failure. [0003] The process of commutation failure is as follows: the AC system fails, causing the AC and DC voltage to drop, the D...

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Problems solved by technology

[0006] In order to overcome the above-mentioned shortcomings of the weak ability to resist commutation failure of LCC-HVDC in the prior art, the present invention provides a method and device for coordinated control between the synchronous condenser and LCC-HVDC. First, the failure judgment module judges whether the AC system occurs Fault, if it is, calculate the cut-off angle deviation according to the cut-off angle of LCC-HVDC, then determine the voltage deviation according to the cut-off angle deviation, and calcula

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