双馈风力发电机在电网电压小幅骤降时的保护策略  

Protection strategy of DFIG under grid voltage narrow dip

作　　者：蔡帜[1] 刘建政[1] 梅红明[1] 王健[1] 刘树[1] 

机构地区：[1]清华大学电机系电力系统国家重点实验室,北京100084

出　　处：《电力系统保护与控制》2009年第21期41-44,共4页Power System Protection and Control

摘　　要：提出了一种双馈风力发电机(DFIG)在电网电压小幅骤降时抑制变频器电压和电流波动的保护策略。传统的DFIG控制方式中通常认为电网电压是理想不变的,所以当发生电压骤降的情况时,双馈电机的转子电流、直流电容电压则会因为电网电压的突变而发生电流和电压跳变和波动,可能会对风电机组的变频器造成损坏。在改进双馈电机转子侧变换器的控制策略的基础上,通过改进整流侧变换器控制策略和增加卸荷电路,减小了直流电压的波动和幅值,提高了系统的暂态稳定性。最后,通过仿真一台1.5MW双馈风力发电机在电网电压小幅骤降故障状态下的运行情况,验证了其正确性和有效性。A protection strategy to limit the converter step current and voltage of doubly-fed induction generator （DFIG） during a grid voltage dip is proposed. Traditional DFIG control schemes consider grid voltage to be ideal unchanged to simplify the design of rotor controller. When the grid falls, the converter may suffer from the rotor step overcurrents and overvoltages in DC-links. In order to enhance the dynamic stability of DFIG, both the rotor excitation control method and DC-link voltage control method are improved in this protection strategy. To realize the protection capability better, off-load circuit to limit the DC-link voltage are used. The correctness and validity of this protection strategy has been verified by simulation results on a 1.5MW DFIG riding through voltage dip.

关 键 词：风力发电 双馈电机 不间断运行 矢量控制 卸荷电路 

分 类 号：TM315[电气工程—电机] TM614