DFIG (Doubly Fed Induction Generator) back-stepping-control-based stator harmonic wave current suppressing method in distorted power grid condition

Abstract

The invention discloses a DFIG back-stepping-control-based stator harmonic wave current suppressing method in a distorted power grid condition. Based on the Lyapunov stability theory, the method performs a back-stepping control algorithm design in a unified mathematical model of DFIG ideal and harmonic wave power grid voltages under a static two-phase coordinate system to achieve active and reactive decoupling control. Defects that conventional vector control dynamic performance is not good enough; complex coordinate transformation is required; strict field orientation projects are difficult to realize; the stable state performance of direct power control through a conventional table lookup method is not good enough are overcome. By means of the method, excellent dynamic and static performance can be achieved in an ideal power grid condition.

Description

technical field [0001] The invention belongs to the technical field of wind power generator control, and in particular relates to a stator harmonic current suppression method based on backstepping control of a doubly-fed asynchronous wind power generator under a distorted power grid. Background technique [0002] In the doubly-fed asynchronous wind generator (DFIG) system, the generator stator is directly connected to the power grid through a transformer, and the disturbance in the power grid will directly affect the operation of the generator itself. In addition, the capacity of the excitation converter connected to the rotor is limited, and it can only control the generator with limited capacity. Compared with the wind power generation system based on the full power converter, the doubly-fed asynchronous wind power system is very sensitive to grid faults. The ability to bear is also poor. At the same time, with more and more nonlinear loads and single-phase loads, the num...

AI Technical Summary

Problems solved by technology

Among them, the strict magnetic field orientation and complex coordinate changes required by vector control, and the slow dynamic response speed brought by the proportional integral controller make its engineering application effect not good

The direct power control method of the look-up table method has a simple structure, does not require complex coordinate transformation, and has a fast dynamic response. However, the hysteresis controller makes the active and reactive power fluctuate greatly in the steady state, and the switching frequency of the converter is not fixed, resulting in the current harmonic order. , the filter design is more difficult

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