Double-feed wind generation set virtual synchronous control method in account of frequency domain impedance stability analysis

Abstract

The invention relates to a double-feed wind generation set virtual synchronous control method in account of frequency domain impedance stability analysis, and belongs to the technical field of the wind power generation. The method specifically comprises the following steps: firstly establishing a double-feed wind generation set dq-axle frequency domain impedance model taking a virtual inertia timeconstant and a virtual damping coefficient into consideration for a structure of the double-feed wind generation set virtual synchronous control strategy; secondly, obtaining a recovery rate matrix and a Nyquist curve of the system by utilizing the dq-axle frequency domain impedance model and a power grid model of the double-feed wind generation set; and finally acquiring reasonable values of thevirtual inertia time constant and the virtual damping coefficient by analyzing the stability of the double-feed wind generation grid-connected system by utilizing generalized Nyquist criterion, thereby realizing the double-feed wind generation set virtual synchronous control method in account of frequency domain impedance stability analysis. Through the method disclosed by the invention, the adaptability to the weak grid by the double-feed wind generation set based on the virtual synchronous control can be effectively improved, and the technical support is provided for improving the grid-connected stable running capacity of the double-feed wind generation set under the weak grid.

Description

technical field [0001] The invention belongs to the technical field of wind power generation, and relates to a virtual synchronous control method of a doubly-fed wind generator set considering frequency-domain impedance stability analysis. Background technique [0002] With the continuous increase of wind power penetration, the grid-connected stability problems caused by doubly-fed wind power systems have become increasingly prominent. In particular, most wind farms in my country are located at the end of the power grid and need to be transmitted over long distances through long lines. The grid impedance is large, showing a weak grid characteristic. The stability problems brought about by the interaction between the double-fed wind power system and the power grid under the condition of weak power grid are prominent. [0003] In recent years, subsynchronous resonance caused by the interaction between wind turbine groups and weak power grids has occurred in wind farms in many ...

AI Technical Summary

Problems solved by technology

The main parameters in virtual synchronous control include virtual inertia time constant and virtual damping coefficient. The values ​​of these parameters have a great impact on the performance of doubly-fed wind turbines, and may even lead to grid-connected instability in weak grids. Therefore, it is urgent to study A virtual synchronous control method that takes into account the influence of key parameters on the stability of wind turbines to improve the grid-connected and stable operation capability of doubly-fed wind turbines based on virtual synchronous control in weak grids

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