改进变流器控制提高双馈感应电机低电压穿越能力  

The Improved Control Method of DFIG for Improving LVRT Capability

作　　者：肖翀[1] 马进[1] 吴涵[1] 

机构地区：[1]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《现代电力》2013年第2期64-68,共5页Modern Electric Power

基　　金：国家自然科学基金项目(51077049;50707009);北京市科技新星计划;"111"引智计划(B08013)

摘　　要：随着风电装机容量的增大,电网对风机在并网点电压跌落时的不脱网运行能力提出更高要求。本文通过改进双馈异步电机(DFIG)的变流器控制来提高其低压穿越(LVRT)能力。文中首先结合DFIG数学模型分析其故障时的瞬态现象,提出了合理的转子侧稳态控制策略;接下来以一种提高低压穿越能力的控制策略为基础,分析了其局限性并提出了改进方法。为验证改进控制的效果,采用matlab/simulink仿真,对比电压跌落瞬间改进控制前后的数据。仿真显示:电压跌落至20%的瞬间,采用改进控制法后DFIG转子电流和变流器直流电压较改进前明显减小,满足低电压穿越的要求。With the increasing of wind power installed ca- pacity, the power grid put a higher demand for wind turbine to have continuous operation capability in voltage sag. In this paper, a convertor control method is presented to im- prove the low voltage ride through （LVRT） capacity of dou- bly- fed induction generator （DFIG）. The transient re- sponse to voltage sag is analyzed with the mathematical mod- el of DFIG, and a convertor control strategy of rotor side for steady state is presented firstly. Then based on a control method that can improve LVRT capability, its limitations is analyzed and the improvement scheme is also put forward. To verify the effect of improved control scheme, the physi- cal quantities in voltage sag obtained with and without im- proved control are compared by matlab/simulink simulation. The results show that the magnitude of transient rotor cur- rent and convertor DC voltage obtained by new control strategy is much lower than that in normal control strategy at the moment of terminal voltage dropping to 20%, which meets the requirement of LVTR.

关 键 词：风力发电 双馈异步电机 低压穿越 变流器 改进控制 

分 类 号：TM614[电气工程—电力系统及自动化] TM343