电网短路故障下DFIG的电磁特性研究  

Studies on electromagnetic characteristics of DFIG under short-circuit faults of the grid

作　　者：栗然[1] 李增辉[1] 王义贺[1] 马慧卓[1] 

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),河北保定071003

出　　处：《电力系统保护与控制》2013年第10期13-19,共7页Power System Protection and Control

摘　　要：对电网短路故障下双馈感应发电机(Doubly Fed Induction Generator,DFIG)的电磁特性进行研究以提高DFIG的故障穿越能力。在对实际电网进行简化的基础上,利用电路理论的换路原理以及KVL、KCL定律分别对电网三相短路故障发生时和切除时DFIG定子磁链的动态特性进行了理论研究;仿真分析了电网不同地点、不同短路故障类型下DFIG定子磁链和转子电流的变化特性。研究结果表明,电网短路切除时DFIG定子磁链发生突变,在线路电阻电抗比较小的情况下定子磁链跃变为稳态值而不出现暂态直流分量,从而短路切除时转子中不会出现暂态冲击电流。理论研究与仿真分析表明,短路发生时与切除时DFIG具有不同的电磁动态。To improve the low-voltage-ride-through capability of doubly fed induction generators, electromagnetic characteristics of a DFIG under short-circuit faults at grid are studied. Based on the simplifications of the grid, stator flux dynamics are respectively studied both at appearance and clearance of a three-phase short-circuit fault, utilizing circuit switching rule as well as KVL and KCL principles. Simulations on DFIG＇s stator fluxes and rotor currents are done under faults of different types and at different locations of the grid. It＇s revealed that stator flux of DFIG will abruptly change to its steady-state value at fault clearance with low resistance-reactance ratio of transmission lines, arousing no transient DC flux components in stator. Therefore no transient inrush currents will be induced in rotor at fault clearance. Studies and simulations verify that the electromagnetic characteristics of DFIG at fault clearance are different from those at fault appearance.

关 键 词：双馈感应发电机 风力发电 故障穿越 电磁特性 短路故障 

分 类 号：TM346[电气工程—电机]