基于LCL有源阻尼的DFIG网侧变流器的新型控制策略研究

Study on New Control Strategy for DFIG Grid-side Converter Based on LCL Active Damping

在DFIG并网发电过程中,变流器非线性开关会增加入网电流高频谐波含量,一般的L型滤波很难实现理想的滤波效果。近几年有学者提出一种LCL新型滤波器,相比于L型的滤波器,LCL滤波器体积更小、损耗更小、滤除谐波的效果也更好。但是,LCL型滤波器是一个高阶的系统,控制设计麻烦并伴随着谐振的产生。针对上述缺点本文提出了一种基于LCL有源阻尼滤波器的准比例谐振(proportional resonance,PR)控制策略和电容电流反馈控制方法来简化控制系统和抑制系统的谐振,在Matlab/Simulink软件中建立仿真模型,对上述控制策略进行了仿真验证,仿真实验波形证明了上述控制方法的正确性。

During power generationperiod of DFIG at grid connection,the l^igh frequency harmonic con- tents of the grid current will be increased by the non-linear switch of converter and ideal filtering result is not easy to be achieved by general type L filter. In recent years,a kind of new type LCL filter is pro- posed by some scholars which, compared to type L filter,has smaller volume, smaller loss and better result of eliminating harmonics. However, type LCL filter is a higher design and resonance generation. As for above shortcoming, in order system with this paper a kind complicated control of proportional res- tion model is set up in MATALAB/Simulink software is set up and above control strategy is simulated and verified. And the correctness of above control method is proved by the simulation and experimental waveform.