Study Of Grid-side Converter Based On LCL Filter For Wind Power Generation System

In the MW wind power generation system, the power is large.When using the traditional L-filter, the inductance value is increased in the grid-side converter.So the manufacturing cost is increased and the system dynamic performance is reduced. Using LCL-filter can resolve these problems. The topology and mathematical model of grid-side converter based LCL filter are established, the parameters of LCL-filter are designed. According to the resonance of LCL-filter, the active damping methods are proposed, a variety of current feedback control strategies are analyzed and double closed-loop control strategy is introduced. Taking into account the actual three-phase voltage imbalance in the power system, two kinds of control strategies are studied.One is the AC current controlling strategy that aims to make the AC current sinusoidal and the other one is the power controlling strategy that mainly aims to eliminate the harmonics of the dc link voltage.These stategies are simulated under MATLAB/SIMULINK,the results illustrate that the methods presented in this paper are correct and provide reliable reference to practical engineering.