Control method of doubly-fed asynchronous wind turbine based on dynamic voltage compensator

Abstract

The invention relates to a dynamic voltage restorer-based double-fed asynchronous wind generator unit control method. The method comprises the following steps: (1) building a dynamic voltage compensator-based double-fed asynchronous wind generator unit control system; (2) when a sudden change of a voltage is caused by a fault, obtaining a suddenly changed voltage vector for negative and negative sequence separation by a dynamic voltage restorer DVR; (3) calculating to-be-compensated voltage amount changing along with the time, and simultaneously giving a control signal; (4) outputting the voltage amount by the dynamic voltage restorer DVR, compensating a stator terminal voltage of a variable-speed and constant-frequency double-fed induction generator DFIG to stabilize the stator terminal voltage; (5) obtaining a suddenly changed new grid voltage vector when the sudden change is caused again during a fault period; (6) calculating the to-be-compensated voltage amount changing along with the time according to the suddenly changed voltage vector; and (7) outputting the voltage compensation amount by the dynamic voltage restorer DVR, and compensating the stator terminal voltage of the variable-speed and constant-frequency double-fed induction generator DFIG to stabilize the stator terminal voltage. The dynamic voltage restorer-based double-fed asynchronous wind generator unit control method can achieve stable fault ride-through.

Description

technical field [0001] The invention relates to the technical field of wind power generation, in particular to a control method for a doubly-fed asynchronous wind power generating set based on a dynamic voltage compensator. Background technique [0002] Wind power is currently one of the most mature, economically feasible and widely used new energy generation technologies. Facing the increasingly urgent problems of energy security and environmental degradation, wind energy has been highly valued by governments of various countries, and major countries in the world, including the United States and China, have successively raised the development of renewable energy to the level of national strategies. New energy represented by wind power is gradually becoming an important energy resource in my country, playing an important role in meeting energy demand, improving energy structure, reducing environmental pollution, protecting the ecological environment, and promoting economic a...

AI Technical Summary

Problems solved by technology

[0012] If the voltage is continuously fully compensated during the fault period and the influence of grid disturbance on the wind turbine is completely isolated, the wind turbine will be able to continue to run stably. is the full power), the DVR must handle this part of the power, which requires the DVR to be equipped with an energy storage capacity or an energy release device that matches the rated power of the fan, which is extremely uneconomical and almost impossible to achieve in engineering practice

[0013] In view of the above situation, the rotor fast short circuit protection (crowbar) technology is currently used at home and abroad to limit the current of the rotor and protect the RSC. Absorbing a large amount of reactive power from the grid is not only detrimental to the recovery of the grid voltage, but may even aggravate the drop in the grid voltage, causing further failures

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