电网电压跌落对双馈感应发电机轴系的影响分析  

Influence of power system voltage drop on the DIFG shaft

作　　者：程孟增[1] 张建文[1] 蔡旭[1,2] 曹云峰[1] 

机构地区：[1]电力传输与功率变换控制教育部重点实验室,风力发电研究中心,上海交通大学电子信息与电气工程学院,上海20024O [2]海洋工程国家重点实验室,上海交通大学船舶海洋与建筑工程学院,上海200240

出　　处：《电力系统保护与控制》2011年第20期17-23,58,共8页Power System Protection and Control

基　　金：重点实验室基金(AE010803);上海市科学基金(08DZ1200504、09DZ1201303)

摘　　要：为研究电网电压跌落对双馈感应发电机(DFIG)轴系造成的影响,通过对向量法求出的瞬态电流与等效电路法求出的稳态电流进行叠加而得出定子、转子故障电流的近似解析式,进而通过电流求出电机的转矩解析式,并将此种方法用来分析定子端三相对称电压跌落、转子侧变换器断开、投入Crowbar电路情况下的DFIG转矩的变化过程。在理论分析的基础上,建立了2MW双馈感应发电机的PSCAD模型,并对此进行电磁暂态仿真。仿真结果验证了通过瞬态电流和稳态电流进行叠加的方法而求得的DFIG故障转矩的近似解析表达式可以用来分析电机轴系转矩的变化,最后给出了Crowbar电阻的优化值。To study the influence of power system voltage drop on the doubly-fed induction generator （DIFG） shaft, this paper analyzes the electromagnetic torque change within DFIG through approximated analytical expression of stator fault current and rotor fault current obtained by the superposition between transient current based on vector method and steady state current based on equivalent circuit method, and then through the analytical expression of DFIG torque under the following circumstances： stator terminal three-phase symmetrical voltage dip, the rotor side converter are cut off, and the crowbar circuit is put into the operation. Furthermore, a 2MW DFIG model is established by PSCAD based on theory analysis, and the simulation results validate that torque changes of DFIG shaft could be analyzed by the analytical torque expressions of DFIG during grid fault. At last, the optimizing value of Crowbar resistance is given.

关 键 词：电压跌落 DFIG 电磁转矩 CROWBAR电路 轴系 

分 类 号：TM727[电气工程—电力系统及自动化] TM346