基于撬棒保护的双馈电机风电场低电压穿越动态特性分析  

Dynamic Characteristic Analysis of Doubly-fed Induction Generator Low Voltage Ride-through Based on Crowbar Protection

作　　者：徐殿国[1] 王伟[1] 陈宁[2] 

机构地区：[1]哈尔滨工业大学电气工程及自动化学院,黑龙江省哈尔滨市150001 [2]国网电力科学研究院,江苏省南京市210003

出　　处：《中国电机工程学报》2010年第22期29-36,共8页Proceedings of the CSEE

基　　金："十一五"国家科技支撑计划重大项目(2008BAA14B04);国家863高技术基金项目(2007AA05Z422);国家电网公司重点项目(SG0827)~~

摘　　要：为研究风电机组与系统的交互影响,建立了低电压故障下双馈式风电机组(doubly-fed induction generator,DFIG)的保护控制措施与系统动态特性之间的联系,分别从机组安全约束角度和系统区域电压稳定角度,探讨了双馈式风电机组撬棒(crowbar)保护电阻取值、投切控制策略,在分析电机发生短路故障后撬棒保护投入期间电气量特性基础上,给出了双馈电机投入撬棒后定转子电流峰值估算式以及撬棒电阻取值约束式。算例从系统角度分析了不同故障类型、不同投切时间和不同撬棒阻值情况下大范围投入撬棒保护后对风电场周边区域电压稳定的影响,并分析了多风电场在电网大扰动后投入撬棒的相互影响。算例结果表明,选择合适的撬棒阻值和投切控制策略可以提高机组低电压穿越(low voltage ride through,LVRT)能力,并降低风电场在撬棒保护大范围投入后对系统电压稳定的不良影响。For studying the impacts of wind turbines integrated into grid, the relation between the protection of doubly-fed induction generator （DFIG） during low voltage fault and the dynamic characteristic of grid is established from the points of generator operation constrains and district grid voltage stability. Then the resistance value and switching strategy of crowbar are discussed. Based on analyzing the electric characteristic of the voltage or current during the short-circuit fault in wind turbines with crowbar switching, the equation to estimate peak current of stator and rotor of DFIG with crowbar switching and the value range of crowbar resistance are derived. The numeric test analyzes the impacts of crowbar switching on district grid voltage stability with different fault types, crowbar switching time and crowbar resistance values. Also the interaction impact of crowbar switching on multi-wind farms is analyzed. The results show that reasonable crowbar resistance value and switching strategy can improve low voltage ride through （LVRT） ability of wind turbines and reduce bad impacts on district grid voltage stability with large-scale crowbar switching of wind farms.

关 键 词：低电压穿越 双馈感应发电机 撬棒 电压稳定性 

分 类 号：TM614[电气工程—电力系统及自动化] TM761