两种直流侧卸荷直驱风机LVRT分析

Comparative analysis of PMSG LVRT on two different chopper

随着并网风电机组的日益增加,风力机组与电网间的相互影响日益突出。国家电网企业标准Q/GDW 392-2009及国标GB/T19963-2001均对风电机组的低电压穿越能力提出了明确的技术要求。分析了大功率永磁风力发电系统在电网电压跌落时的暂态特性,建立了基于Chopper与超级电容器的两种直流侧卸荷电路及相应的控制策略。并在PSCAD/EMTDC软件环境下搭建了相应的并网仿真模型,仿真对比了在电网电压严重跌落时两种卸荷电路对机组暂态特性的影响。仿真结果表明在网侧电压跌落的时候,两种卸荷方式在稳定直流侧电压和系统恢复方面,各有优势。

With the increase of wind turbine more and more, the interaction of wind power and power grid became increasingly prominent. The enterprise standard of state grid Q/GDW 392-2009 GB/T19963-2001 clarified a clear technical requirements for the LVRT of wind turbine. Based on the voltage drop transient characteristic of large power PMSG, the actual grid connected-PMSG and chopper ultracapacitor, the model of them were set up in PSCAD/EMTDC, specific to the terrible voltage drop of PCC. The two different transient characteristic were simulated and compared of chopper circuits. From the result it is clearly that at the PCC voltage drop, the two different circuits have their own different advantages at the DC voltage and system recovery etc