直驱式风力发电变流系统拓扑方案研究

摘要

为了满足直驱式风力发电系统的大容量、高功率密度以及高可靠性需求,提出同时采用功率模块并联和变流器并联的主电路拓扑方案。首先,采用智能功率模块并联扩大单台变流器的容量,并利用差模电感对其存在的动态环流进行有效抑制,简单可靠;其次,利用六相永磁同步电机中两套三相绕组之间的电气隔离,解决了机侧以及网侧变流器并联存在的零序环流问题,一方面扩大了系统容量,增加系统冗余性和可靠性,同时还可利用谐波对消技术减小注入电网的电流谐波。通过试验对文中所述系统方案的可行性进行了验证。%To meet the demands of direct-driven wind generation system for large capacity,high power density and high reliability,parallel schemes for power modules and converters are both proposed.Firstly,the parallel technology of power modules is used to expand the single converter＇s capacity.The differential mode inductor is adopted to limit the dynamic circulating current,which is simple and reliable.Secondly,by means of the winding-insulation of six-phase permanent magnet synchronous generator,the zero-sequence circulating current among parallel converters is eliminated. The parallel of converters can expand the system capacity,and improve the redundancy and reliability. Also,the total harmonic currents injected into grid can be reduced by use of interleaved space vector modulation.The feasibility of the converter system scheme is verified by the experiment.