Wind power plant stability evaluation method and system based on active equipment node impedance

Abstract

The invention relates to a wind power plant stability evaluation method and system based on active equipment node impedance. The method comprises the steps of judging whether impedance models of active equipment and passive equipment are stable or not; determining an active sub-network and a passive sub-network according to the network topology connection relation when the impedance models of the active equipment and the passive equipment are stable; and determining an equivalent open-loop transfer function, judging whether a Nyquist curve of the equivalent open-loop transfer function wraps a (-1, 0j) point or not, if the second judgment result shows that the Nyquist curve of the equivalent open-loop transfer function wraps the (-1, 0j) point, determining an oscillation mode according to the equivalent open-loop transfer function, and calculating an oscillation participation factor of the active equipment according to the oscillation mode; and determining the active equipment with the maximum participation degree according to the oscillation participation factor of the active equipment, and reconfiguring the active equipment with the maximum participation degree. The method effectively reduces the analysis difficulty of the complex network, is easy to expand, and has the advantages of simple and efficient analysis process.

Description

technical field [0001] The invention relates to the technical field of impedance analysis, in particular to a wind farm stability evaluation method and system based on active equipment node impedance. Background technique [0002] With the continuous development of wind power generation and high-voltage AC-DC transmission technology, China's three northern regions have basically formed a grid pattern of large wind power base development and DC transmission. The weakly synchronous grid system dominated by a high proportion of power electronic devices such as wind turbines, HVDC, and reactive power compensation is the main feature of China's wind farm grid-connected system. The complex control functions of a large number of devices are intertwined with the characteristics of the weak synchronous grid, which makes the dynamic characteristics of the wind farm grid-connected system extremely complex and the stability problem is prominent. [0003] The impedance analysis method h...

AI Technical Summary

Problems solved by technology

However, the impedance network analysis has the disadvantages of high dimensionality and difficulty in analysis, and the influence of frequency coupling is poor in scalability, which makes it difficult to implement the optimization of control parameters in multi-machine network systems.

At the same time, after the oscillation occurs, the existing analysis methods are difficult to carry out effective risk assessment on the oscillation, which is not conducive to the optimal design of system parameters

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