Power system grouping and stability margin evaluation system and power system grouping and stability margin evaluation method based on wide area measurement system (WAMS)

Abstract

Provided are a power system grouping and stability margin evaluation system and a power system grouping and stability margin evaluation method based on a wide area measurement system (WAMS). The power system grouping and stability margin evaluation system comprises a WAMS data platform, and a pretreatment unit and a transient analysis unit are sequentially connected at the back of the WAMS data platform. The WAMS data platform, the pretreatment unit and the transient analysis unit perform bi-directional transmission of information with a state quantity deposit unit. The method comprises: the WAMS data platform measures power-angle values of a machine set, the power-angle values are transmitted to the transient analysis unit after processed by the pretreatment unit, rotor angles of the machine set relative to local inertia center coordinates are calculated through the transient analysis unit and ranked from big to small, (n-1) angle clearances are calculated, the first three clearances are selected to serve as a leading mode at the moment, then an equivalent system trajectory corresponding to the leading mode is calculated, and finally a stability margin of the equivalent system trajectory is calculated. A network structure of a power system and models and parameters of elements do not need obtaining in advance, users do not need to install a WAMS device on each machine set, and grouping calculation can be performed quickly in real time after the system is disturbed or fails.

Description

technical field [0001] The invention belongs to the technical field of power systems, and in particular relates to a WAMS-based power system grouping and stability margin evaluation system and method. 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 sufficient threshold values ​​can be used as...

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Problems solved by technology

Its inherent defect is the lack of qualitative stability identification criteria in engineering, and only limited observation time and sufficient threshold value can be used as the criteria for system stability

In addition, it is completely dependent on the model and parameters of the components. When the model or parameters are not completely accurate, the results must have errors

[0004] The direct method is a strictly quantitative transient stability analysis method, which can give the transient stability limit of the system based on the sensitivity method, but the calculation of the transient energy is limited by the model, and the error of the energy function used will affect the calculation results

In addition, the direct method is only suitable for analyzing the stability of the first pendulum in the power system, which has certain limitations

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