Method for estimating local voltage stability margin

Abstract

The invention discloses a method for estimating the local voltage stability margin. The method comprises the following steps of firstly, obtaining the reactive power consumption rate of each electric generator in a power generation system, obtaining the reactive power consumption rate of the electric generator to be bordered in a reactive mode at the same time, and generating bordering by the electric generator at the tk time; secondly, judging the electric distance between the electric generator to be bordered in the reactive mode and the monitoring point in the first step; thirdly, if saddle node bifurcation determining and / or limiting inducing bifurcation determining are / is set up, considering reactive bordering of the electric generator to cause instability, and conducting the instability control strategy; if the saddle node bifurcation determining and / or the limiting inducing bifurcation determining are / is set up, considering the reactive bordering of the electric generator to be stable, and estimating the local voltage stability margin of the monitoring point after the reactive bordering occurs. When system changes are large, estimation is carried out on the local voltage stability margin, errors of the estimated result of the local voltage stability margin can be reduced, and the accuracy of the estimated result of the local voltage stability margin can be improved.

Description

technical field [0001] The invention belongs to the technical field of power system evaluation and control, in particular to a method for estimating a local voltage stability margin. Background technique [0002] In recent years, some large power grids in the world have successively caused huge economic losses and large-scale blackouts due to voltage stability accidents. Therefore, the voltage stability of power systems in this industry has attracted increasing attention. [0003] The evaluation of power system voltage stability is an important part of power system operation and control, and the factors affecting voltage stability generally have the characteristics of dispersion and locality. With the emergence and wide application of phase angle measurement unit (PMU), the evaluation method of local voltage stability margin using local measurement data has gradually been paid attention to and applied. However, subject to the limitations of the evaluation method of the loca...

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Problems solved by technology

However, subject to the limitations of the evaluation method of the local voltage stability margin, that is, since the evaluation method of the local voltage stability margin is essentially a linear estimation of the data within a measurement window, when the system changes greatly, such as the system Changes in the operating mode, disconnection of the machine, etc., the data in a measurement window may have a relatively high degree of nonlinearity, which may lead to inaccurate local evaluation results

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