Double close-loop control method for grid-connected double feed type wind generator and device adopting same

Abstract

The invention discloses a double close-loop control method for a grid-connected double feed type wind generator. The method comprises the steps of acquisition, coordinate transformation, generator rotor current inner ring control, and generator stator voltage outer ring control, wherein the acquisition step refers to acquiring the three-phase voltage of a generator stator, the three phase current of a generator stator, the voltage of a power network, the current of a generator rotor, and the rotational speed of the generator rotor; the coordinate transformation step refers to converting the acquired parameters into a synchronous rotational coordinate system through Clark conversion and Park conversion; the generator rotor current inner ring control step refers to inputting the generator rotor current into a proportion integrator and output the components d and q of the voltage of the generator rotor to perform excitation control to the grid-connected double feed type wind generator; and the generator stator voltage outer ring control step refers to inputting the voltage of the generator stator into the proportion integrator, and outputting the components d and q of the voltage of the generator stator to perform excitation control to the grid-connected double feed type wind generator. The double close-loop control to the grid-connected double feed type wind generator can be realized through utilizing the generator rotor current inner ring control and the generator stator voltage outer ring control.

Description

technical field [0001] The invention relates to the technical field of wind power generation, and more specifically, to a double-closed-loop control method and control device of a grid-connected doubly-fed wind power generator. Background technique [0002] The doubly-fed wind turbine is a kind of alternator, which has the advantages of flexible control, adjustable power factor, high efficiency, and small capacity of the frequency conversion device. It is the key component of the most widely used variable-speed constant-frequency wind turbine. [0003] At present, the control of double-fed wind turbines generally adopts the method of vector control, which is highly dependent on the parameters of the generator, especially the mutual inductance parameters of the motor. [0004] For example, the Chinese patent application with application number CN200410009701.8 discloses a variable-speed constant-frequency doubly-fed generator system and a grid-connected control method thereof...

AI Technical Summary

Problems solved by technology

[0006] The disadvantages of the existing technology are: when the generator is actually running, the parameters of the motor, especially the mutual inductance parameters, will fluctuate, so that the output of the entire control system will be inaccurate, such as the amplitude, frequency, and phase of the stator voltage. When connected to the grid, a large inrush current will be generated, and in severe cases, it will oscillate, making the system enter an unstable state, and ultimately reduce the reliability of the entire system

Due to the continuous increase in the capacity of wind turbines, in actual operation, it is necessary to consider the instability of the grid-connected state caused by parameter changes and how to realize the soft grid-connected problem of the unit

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