Strong-connection power grid out-of-step disconnection method

Abstract

The invention relates to a strong-connection power grid out-of-step disconnection method. The theory of an extended equal area criterion (EEAC) dominant mode is regarded as a basis, perturbed trajectories rocking curves are used for recognizing perturbed system coherent generators, and coherent areas can be divided further. Out-of-step disconnection criteria applicable to a strong-connection power grid and based on sections are selected and composed of u cosine phi criteria and voltage amplitude criteria, the combination criteria can judge out-of-step of the strong-connection power grid effectively, and the time and the positions of oscillation centers can be captured. The position of a disconnection point is confirmed according to out-of-step sections formed by junctors where the oscillation centers are located. Correct disconnection time and disconnection range are selected for setting devices, and a disconnection command action device is started after a certain requirement is met. Effective generator shedding and load shedding measures are taken according to power shortage of a subsystem after disconnection. The strong-connection power grid out-of-step disconnection method is applicable to out-of-step disconnection schemes of the strong-connection power grid, damage accidents on stability of the strong-connection power grid can be avoided, and reliable guarantee is provided for safe and stable operation of the strong-connection power grid.

Description

technical field [0001] The invention relates to a power grid fault judgment method, in particular to a out-of-synchronization disconnection criterion of a strongly connected power grid. Background technique [0002] With the gradual realization of the interconnection between China's cross-regional large power grids, the grid structure is developing in the direction of a strongly connected power grid, and the level of safe and stable operation of the power grid has also been greatly improved. Although we have taken effective measures to prevent blackouts, due to the unpredictable superposition of multiple faults, the occurrence of out-of-step oscillations in power systems is inevitable. In view of the new stage of the development of the strong-connected power grid in the existing power system, it is of great significance to study the out-of-step separation of the strong-connected power grid. It is necessary to study the division method of the coherence area of ​​the strong-co...

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Problems solved by technology

[0004] The oscillation center of strongly connected power grid usually falls on the out-of-step section composed of multiple tie lines, while the traditional out-of-synchronization separation criterion type is relatively single, and most of the criteria are not perfect enough to be applicable to the section. The out-of-synchronization decoupling criterion of the step section can judge the out-of-synchronization of the strongly connected power grid, and determine the time and position of the out-of-synchronization decoupling oscillation center

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