Online evaluation method of electric power system dynamic stability

Abstract

The invention discloses an online evaluation method of electric power system dynamic stability. The online evaluation method comprises the steps of step 1, carrying out high-frequency sampling by utilizing a PMU (Power Management Unit), and extracting an oscillation mode for sampling data by utilizing a matrix pencil identification method; step 2, detecting low-frequency oscillation, and emitting low-frequency oscillation warning if a damping ratio of the detected oscillation mode is lower than a set threshold value; step 3, carrying out small perturbation calculation on a system model in a current running mode through a frequency domain analysis method, and obtaining a characteristic value, a characteristic vector, a corresponding unit and participated factor information; and step 4, screening out information of a low-frequency oscillation mode from a small perturbation calculation result according to the low-frequency oscillation mode which is determined by the matrix pencil identification method, regulating a related electric power generator to output, and obtaining tide stability limit of call lines between related domains through time-domain simulation at the same time. According to the online evaluation method disclosed by the invention, the influence of noise is effectively avoided, the identification accuracy is improved, the calculating speed and the calculating efficiency are increased, and the online dynamic safety evaluation effect of the electric power system is obviously improved.

Description

technical field [0001] The invention relates to an online safety and stability analysis of a power system, in particular to an online evaluation method for the dynamic stability of a power system that integrates matrix bundle identification and frequency-domain eigenvalue analysis. Background technique [0002] As my country's power grid construction continues to develop by leaps and bounds, by the end of 2012, China's national installed capacity has surpassed that of the United States and ranked first in the world. Problems are intertwined and mutual constraints increase, so that the effect of strengthening the grid structure and strengthening the stability level cannot be simply evaluated, and it needs to be considered in the context of a large system. One of the main reasons for this phenomenon is that the importance of dynamic stability level in various stability constraints in large-scale AC interconnected grids cannot be ignored. For example, summarizing the conclusion...

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Problems solved by technology

At present, the online identification algorithm has fast calculation speed and good accuracy, but it can only give the information of a certain oscillation mode, and there is no global information. Although the small disturbance calculation based on frequency domain eigenvalue analysis can give global information, it is affected by parameters. Large, and all online calculations are too heavy

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