An application method of node voltage stability index of multi-feed AC-DC system

Abstract

The invention provides an application method of a node voltage stability index of a multi-infeed AC / DC system. The node voltage stability index of the multi-infeed AC / DC system provides a comprehensive, integrated and effective quantitative index for the large-disturbance voltage stability degree in a multi-DC drop point region, has the similarities of employing the bus short-circuit capacity as a denominator and considering the influence of a multi-loop DC in comparison with an existing multi-infeed short-circuit ratio index, but also considers the region load influence, the voltage stability effects of various dynamic reactive compensation devices and the like as a comprehensive and integrated large-disturbance voltage stability degree measurement index; and these integrated factors are weighted as molecules according to the dynamic reactive demand condition. The multi-infeed AC / DC system provided by the invention is concise and clear in voltage stability index under the large-disturbance condition and convenient to apply, provides the comprehensive, integrated and effective quantitative index for the large-disturbance voltage stability degree in the multi-DC drop point region, and can provide important reference indexes for power network planning, multi-loop DC access, system stabilizing measures designation and the like.

Description

technical field [0001] The invention relates to an application method of a voltage stability index in the case of a large disturbance of a multi-infeed AC-DC system, and belongs to the technical field of power system safety and stability analysis. technical background [0002] The unbalanced distribution of energy resources and economic development determines that China Southern Power Grid needs to carry out west-to-east power transmission and cross-regional resource optimization for a long period of time. Prospects With the large-scale DC centralized feed-in of the Southern Power Grid to the receiving-end grid, the load density of the receiving-end system is further increased, and the problems of AC-DC interaction, voltage stability, and short-circuit current exceeding the standard of the power grid become more prominent, and the operation risk and difficulty of operation control of the power grid are likely to increase. [0003] In multi-infeed AC / DC systems, since faults...

AI Technical Summary

Problems solved by technology

At present, since the multi-infeed short-circuit ratio and the effective short-circuit ratio reflect the strength of the grid structure of the multi-infeed AC-DC system and the reactive voltage support capacity of the grid for the commutation busbar, the voltage stability of the multi-infeed AC-DC system is mainly used However, the physical concepts of these short-circuit ratio indicators mainly reflect the degree of mutual influence between DC, and cannot indicate the degree of influence of DC power loss on the voltage drop of the receiving end grid, nor can they It directly and effectively reflects the stability of the multi-DC feed-in system. In addition, it does not fully reflect the load impact and the voltage stabilization effect of various dynamic reactive power compensation devices. Therefore, more comprehensive, comprehensive and effective indicators or calculation methods are needed to more directly It reflects the voltage stability of areas with multiple DC drop points, and quantitatively determines the impact of DC drops with different capacities and different access methods on stability in the area

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