基于分布式控制的并联型直驱风力发电的环流抑制策略

摘要

In the Direct-drive wind power generation system , the using of parallel converter technology can reduce the power of a single converter , increase system capacity and realize redundancy system . Dis-tributed control can better realize the redundancy, but in the distribut-ed control mode , there is a differential-mode circulation and com-mon-mode circulation , which can make the three-phase current distor-tion , uneven flow , asymmetric waveform and other issues , increase the power semiconductor device loss , reduce system efficiency . On the basis of the analysis of the parallel converter model , the expression of differ-ential-mode and common-mode circulation in the dq0 coordinate system are derived . And the control strategy is proposed , which is effective to suppress the generation-side circulation and the line-side circulation . The simulation and experimental results verify the correctness of the proposed method .%在直驱型风电发电系统中，采用变流器并联技术可以减少通过单个变流器的功率，增加系统容量，实现冗余系统。采用分布式控制能更好地实现冗余，但存在差模环流和共模环流，会使交流电流发生畸变、不均流、波形不对称等问题，增加功率半导体器件损耗，降低系统效率。本文在分析并联变流器模型的基础上，推导出dq0坐标系下差模和共模环流表达式，提出抑制该环流的控制策略，并有效抑制机侧环流和网侧环流。同时，采用仿真和实验验证了所提方法的正确性。