Power system low-frequency oscillation online identification method based on recursive stochastic subspace

A random subspace, low-frequency oscillation technology, applied in electrical components, circuit devices, AC network circuits, etc., can solve problems such as large redundancy, difficulty in online identification engineering, and time-consuming algorithms
CN104993480AActive Publication Date: 2015-10-21FUZHOU UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
FUZHOU UNIV
Publication Date
2015-10-21

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Abstract

The invention relates to a power system low-frequency oscillation online identification method based on a recursive stochastic subspace. According to the method, in order to solve the problem that the real-time performance and dynamic identification effect of low-frequency oscillation modal identification are poor due to the need of SVD decomposition with high algorithm complexity in a stochastic subspace identification algorithm, a forgetting factor is introduced to update a Hankel covariance matrix, and a projection approximation subspace tracking method is used to perform recursive operation on the subspace. Thus, SVD operation is avoided, and the computational complexity is reduced significantly. In each recursive calculation, the complexity of the algorithm of the invention is 3In+O(I<2>), which is far lower than O(I<3>), the complexity of SVD calculation. By adopting the method of the invention, the real-time performance of identification can be improved effectively. The invention is suitable for online identification of low-frequency oscillation modal, and can provide effective support for power system online monitoring and stability analysis under multiple spatial and temporal scales.
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Description

technical field

[0001] The invention relates to the technical field of power system low-frequency oscillation analysis, in particular to an online identification method for power system low-frequency oscillation based on a recursive random subspace. Background technique

[0002] With the interconnection of large-scale power systems and the grid-connected operation of large-scale wind and photovoltaic power generation systems and their increasing proportion in the installed capacity of the grid, the problem of weakly damped low-frequency oscillations in the grid has become increasingly prominent, seriously affecting the stable operation of the grid and power quality control. Real-time and accurate identification of each modal information of the oscillation, positioning the oscillation area and the unit, and then applying effective low-frequency oscillation suppression measures are extremely critical. At present, the wide application of wide area measurement system (WAMS), esp...

Claims

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