双馈风力发电机组的两种低电压穿越方案对比分析  

Two kinds of low voltage ride-through schemes comparison analysis of double fed wind generator

作　　者：欧阳惠[1] 李培强[1] 李欣然[1] 朱琳[1] 户龙辉 

机构地区：[1]湖南大学电气与信息工程学院,湖南长沙410082

出　　处：《电工电能新技术》2014年第8期43-48,共6页Advanced Technology of Electrical Engineering and Energy

基　　金：国家自然科学基金资助项目(51277055)

摘　　要：随着风力发电量的急剧增加,新的电网运行准则对并网机组低电压穿越能力提出了更高要求。本文通过DFIG的数学模型,分析了Crowbar电阻的合理取值范围,提出了在故障切除前退出Crowbar电路的低电压控制策略。最后在Matlab/Simulink中建立并网仿真模型,通过仿真探讨了网侧变流器最大限值电流对低电压主要性能指标直流母线电压的影响,得出合理的限流值能改善系统自身LVRT能力的结论;在此基础上,对比转子侧Crowbar电路、Crowbar电路与直流侧卸荷电路相结合两种低电压实现方案,仿真结果表明后者通过提高Crowbar阻值能够吸收多余的能量,在抑制定转子侧的暂态浪涌电流和稳定直流母线电压方面较前者更有效。With the dramatic increase of the proportion of wind power in the power system, the standard for the low voltage ride through capability of the wind generators combined to the grid is more and more strict. In this paper, through the mathematical model of DFIG, the reasonable value range of the resistance of Crowbar is analyzed, and moreover,the low voltage control strategy for cutting off the Crowbar circuit before the clearing of fault is proposed. Finally the grid-model is built up in Matlab/Simulink, and the impact of the maximum limiting current value of the grid-converter on the DC bus voltage, which counts as one of the main low voltage performance indicators, is dis-cussed. Based on the above discussion, two low-voltage schemes are compared:one is the rotor side Crowbar cir-cuit, and the other is with additional DC side unloading circuit, and the simulation results show that by increasing the Crowbar resistance value, the latter can absorb the excess energy, which makes it more effective than the former to suppress the transient inrush current in the stator and rotor windings as well as to stabilize the DC bus voltage.

关 键 词：风力发电 低电压穿越 CROWBAR电路 卸荷电路 直流母线电压 

分 类 号：TM743[电气工程—电力系统及自动化]