Method for identifying instability of power system based on geometrical characteristics of double phase planes

Abstract

The invention relates to a method for identifying the instability of a power system based on geometrical characteristics of double phase planes. The method comprises the following steps: calculating an index tau of reflecting the geometrical characteristics of angular velocity-power angle phase planes of the first phase plane according to the power angle delta of a generator and the angular velocity deltaomega of a generator rotor, which are measured by a wide area measurement system (WAMS) at current moment; calculating an index mu of reflecting the geometrical characteristics of unbalanced power-power angle phase planes of the second phase plane according to the power angle delta of the generator and the unbalanced power deltaP of the generator, which are measured by the WAMS at the moment same as that in the previous step; when mu and tau are not greater than zero at the same time, calculating the indexes mu and tau at the next moment again; and when mu and tau are greater than zero at the same time, obtaining the judgment that the system is out of the transient stability. The method provided by the invention is high in efficiency, good in accuracy and suitable for real-time prediction and control.

Description

technical field [0001] The invention relates to a transient instability identification method in the field of power systems, in particular to a power system instability identification method based on dual-phase plane geometric features. Background technique [0002] The analysis and judgment of power system transient stability is one of the classic problems in power system research. So far, there are four main types of analysis methods for studying transient stability problems, namely numerical integration method, direct method, hybrid analysis method and stability analysis method based on trajectory information. [0003] Numerical integration method is the basic method of power system transient stability analysis, it can adapt to various mathematical models of detailed components, and the analysis results are accurate and reliable. Its inherent defect is the lack of qualitative stability identification criteria in engineering, and only limited observation time and sufficie...

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Problems solved by technology

The principle of this kind of device based on direct measurement of power angle and angular velocity is simple and intuitive. However, since the measured power angle and angular velocity of a certain generator cannot constitute a strict out-of-step criterion, this kind of device can only be compared with the pre-determined Compared with the critical threshold value of the set power angle or angular velocity, in actual operation, due to the difference in the operation mode before the fault, the fault situation and the network structure after the fault is removed, the threshold value will be difficult to determine

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