Method for improving dynamic reactive power coordination control capability of doubly-fed wind turbine generator

Abstract

The invention discloses a method for improving the dynamic reactive power coordination control capability of a doubly-fed induction generator set, and the method comprises the following steps: S1, analyzing the reactive power operation range of a DFIG stator side converter and a grid side converter and the change rule of the power operation range of the DFIG at different terminal voltages in combination with the doubly-fed induction generator set, obtaining a change curve of the total reactive power regulation capability of the DFIG system along with the active power; s2, determining a reactive power coordination control strategy of the DFIG stator and the grid-side converter; and S3, identifying an active additional controller PI parameter value based on a reactive difference value by adopting an improved genetic control algorithm, and continuously correcting an independent variable parameter to enable the target function to be minimum. And when the reactive power demand of the system is higher than the reactive power output limit of the wind turbine generator, an active power additional control method based on reactive power vacancy is adopted, so that the reactive power demand of the system is met while the output is reduced to the minimum, namely, the stable and safe operation of the power grid system is maintained on the premise of ensuring the power generation benefit.

Description

technical field [0001] The invention relates to the technical field of wind power generation, and more particularly to a method for improving the dynamic reactive power coordination control capability of a doubly-fed wind turbine. Background technique [0002] According to the data released by the International Energy Agency, the proportion of wind power in the energy structure has increased year by year since 2009, with an average annual growth rate of 0.44%. In 2017, wind power accounted for 5.6% of global energy demand, and the penetration rate of wind power continued to increase. . At present, the installed capacity of double-fed induction wind turbines (DFIG) accounts for about 90% of the market share. It is the mainstream model today, but it is accompanied by the impact of grid voltage security and stability brought about by large-scale wind power grid integration. [0003] At present, there are two main ways of reactive power compensation in wind farms: investing in ...

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Problems solved by technology

However, the above studies are all normal control by DFIG under the condition of meeting the reactive power demand of the system. Once the reactive power demand of the system increases and the reactive power supply of the wind turbine is insufficient, the voltage at the connection point of the wind farm connected to the grid is unstable, which seriously affects Grid security and stability

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