Control method for frequency response of doubly-fed generator

Abstract

The invention discloses a control method for the frequency response of a doubly-fed generator. The method comprises the following steps: 1, creating low, medium and high-wind speed interval criteria according to the initial deloading rate del% by a wine speed identification unit, and when the initial deloading rate is changed, updating data in time and performing interval identification on the wind speed; 2, setting a variable drooping coefficient Rf according to a setting calculation formula of a corresponding wind speed interval during low, medium or high wind speed; 3, monitoring a system frequency deviation delta f by a system frequency deviation monitoring unit, and when the system frequency deviation delta f exceeds a set dead region frequency range, triggering the control on the variable drooping coefficient Rf of the doubly-fed generator; 4, controlling the frequency response of the doubly-fed generator according to the currently set variable drooping coefficient Rf and the system frequency deviation delta f by a custom drooping property unit. According to the method, the capability of controlling the frequency response of the doubly-fed generator is improved by setting the variable drooping coefficient.

Description

technical field [0001] The invention relates to a frequency response control method of a doubly-fed wind turbine, belonging to the field of active power control of the wind turbine. Background technique [0002] At present, there are many literatures at home and abroad devoted to the research of frequency response control of doubly-fed wind turbines, and some mature control methods have been proposed and successfully applied to actual wind farms, such as integrated frequency response control using virtual relationship control and droop control method, but because the doubly-fed wind turbine works at the maximum power operating point before the frequency response, it cannot provide active power reserve capacity, which can only alleviate the speed of frequency drop to a certain extent, and will also cause a secondary drop in frequency. [0003] Therefore, many literatures further propose to pre-control the load reduction operation of the DFIG, so that a certain active power re...

AI Technical Summary

Problems solved by technology

However, if the traditional fixed droop coefficient control method is adopted, if the droop coefficient is set too small, it will cause the over-response of the DFIG, the rotor speed cannot be recovered, the DFIG cannot operate stably, and it will also cause the grid frequency to drop twice. Even the frequency collapses; if the droop coefficient is set too high, the available capacity of the DFIG real-time unit cannot be fully utilized, which weakens the frequency adjustment capability of the DFIG

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