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 calculate the synchronous condenser control input according to the voltage deviation, and finally determine the synchronization according to the synchronous condenser control input The excitation voltage of the condenser, and according to the excitation voltage of the synchronous condenser, the coordinated control between the synchronous condenser and the LCC-HVDC is realized, and the LCC-HVDC commutation failure resistance is improved through the coordinated control between the synchronous condenser and the LCC-HVDC ability

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