Method for establishing equivalent model of wind farm

Abstract

The invention discloses a method for establishing an equivalent model of a wind farm. The method comprises a step of establishing a sweep frequency module and an excitation source main circuit on the Draft of an RTDS simulation platform, a step of establishing the detailed model of a power grid and setting the power supply in the power grid to be zero, a step of writing a batch processing script in the Runtime of the RTDS simulation platform, and changing the output value of a controlled voltage source in the Draft in real time, displaying sweep frequency voltage and current in a specific image, and storing data into a specified folder, a step of calculating an admittance value under each frequency according to sweep frequency voltage and current data, and the fitting phase-to-ground admittance and mutual admittance as a rational function in Matlab by using a vector fitting function, and a step of storing the rational function obtained through fitting into the specified folder with a certain format. The equivalent model established by using the above method can accurately restore the electromagnetic transient response of the wind farm, and thus a foundation is laid for the study of the electromagnetic transient characteristics of a wind farm access power grid.

Description

technical field [0001] The invention relates to the technical field of equivalent modeling and simulation of new energy power sources, in particular to a method for establishing an equivalent model of a wind farm. Background technique [0002] At present, wind power is developing rapidly all over the world, and its proportion in the power grid is gradually increasing. However, there are huge differences in the operating principles of wind power and traditional thermal power represented by synchronous generators. In particular, variable-speed constant-frequency wind turbines need to rely on power electronic converters to connect to the grid, which makes the electromagnetic transient process of wind power quite different from that of synchronous generators. At this stage, the research on the influence of wind farm access on the electromagnetic transient characteristics of power grid has become a hot topic. [0003] In the prior art, the research on the electromagnetic transi...

AI Technical Summary

Problems solved by technology

In fact, there are many units in the wind farm and they are distributed in different geographical locations. Their electromagnetic transient characteristics are the comprehensive response of multiple components. The electromagnetic transient process of the wind farm under large disturbances is very complicated.

Therefore, the simple capacity weighting method cannot truly reproduce the actual electromagnetic transient process of the wind farm

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