在分析变速恒频双馈风力发电机组和Crowbar电路工作原理的基础上,建立双馈风力发电系统低电压穿越(LVRT)控制模型和Crowbar控制策略。在PSCAD/EMTDC仿真软件中搭建了双馈感应发电机(DFIG)系统模型和LVRT控制模型。针对电网三相对称短路故障下Crowbar的投切策略进行了仿真研究。仿真结果验证,所提策略能实现双馈风力发电机的低电压穿越。
As the wind power penetration from large scale wind turbines, which are based on variable speed constant frequency doubly-fed induction generators(DFIG) ,has been increasing rapidly in power system,the effects of large scale wind farms on the stability of regional power system are becoming very remarkable. On the basis of analyzing active Crowbar circuit topology and the DFIG topology, the DFIG mathematical model with considering the changed grid voltage was adopted and the control model of LVRT with Crowbar circuit was established. By use of PSCAD/EMTDC the simulation modules of VSCF double-fed wind tubrine were set up and the dynamic stability of double-fed wind tubrine connected into power grid with considering LVRT was simulated. The simulation results show that the established DFIG control model and the Crowbar circuit are in favor of achieving the LVRT of DFIG.