抑制超速脱网的双馈感应风电机组低电压穿越控制策略研究  

A DFIG Wind Turbine Low-voltage Ride-through Control Strategy Restraining Over-speed-tripping-off from Grid

作　　者：严干贵[1] 侯延鹏[1] 王健[1] 王昱博[1] 

机构地区：[1]东北电力大学电气工程学院,吉林132012

出　　处：《电工技术学报》2015年第23期146-154,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金国际合作与交流项目(51261130471)资助

摘　　要：配备主动式Crowbar保护是为避免电网低电压诱发双馈感应风电机组(DFIG)转子侧变流器(R-VSC)过电流/过电压而脱网的低电压穿越措施,但是Crowbar保护的长时间投入(一般大于200 ms)可能会导致转子超速脱网。基于双馈感应风电机组数学模型,分析了Crowbar投入导致转矩失衡而引起转子超速的动态过程,设计了一种Crowbar保护主动退出判据,并构建了转子变流器重启控制策略,形成了由"Crowbar保护策略+R-VSC重启控制策略"构成的抑制超速脱网的新型DFIG-LVRT措施。利用PSCAD/EMTDC仿真平台搭建了DFIG-LVRT仿真系统,对所改进的低电压穿越策略的有效性进行了仿真验证。To avoid the trip-off from grid caused by over-current / over-voltage of rotor-side converter（ R-VSC） during voltage dips,an active crowbar protection is often set to by-pass the R-VSC for doubly-fed induction generator based wind turbine（ DFIG-WT） to protect the whole system and implement low voltage ride through（ LVRT）. If the crowbar circuit put into operation lasts for a relatively long time（ generally above200 ms）,DFIG over-speed-tripping-off from grid may happen. Based on the mathematical model of DFIG,the transient over-speed process of DFIG caused by the unbalance of wind generators＇ rotor torques is analyzed. Then a novel LVRT scheme is presented consisting of an initiative cut-off criterion of Crowbar circuit and R-VSC restarting control strategy. At last,the new DFIG-LVRT scheme of restraining over-speed-tripping-off from grid is formed. The simulation system of DFIG-LVRT is established under PSCAD / EMTDC, and simulations are conducted to demonstrate the validity of the improved method.

关 键 词：双馈感应风电机组 低电压穿越 主动式Crowbar保护 超速脱网 

分 类 号：TM315[电气工程—电机]