Coordinated control method and device between synchronous condenser and LCC-HVDC

Abstract

The present invention provides a coordinated control method and device between a synchronous condenser and an LCC-HVDC. First, a fault judgment module is used to judge whether the AC system is faulty, and if so, the off-angle deviation is calculated according to the off-angle of the LCC-HVDC, and then Determine the voltage deviation according to the turn-off angle deviation, and calculate the control input of the synchronous condenser according to the voltage deviation, and finally determine the excitation voltage of the synchronous condenser according to the control input of the synchronous condenser, and realize the synchronous condenser and the synchronous condenser according to the excitation voltage of the synchronous condenser. Coordinated control between LCC‑HVDC improves LCC‑HVDC commutation failure resistance through coordinated control between synchronous condensers and LCC‑HVDC. The technical solution provided by the invention can stabilize the bus voltage through the reactive power output by the synchronous condenser, improve the resistance to commutation failure of LCC-HVDC, and reduce the probability of commutation failure of LCC-HVDC.

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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