提高双馈式风力发电机机电暂态模型crowbar保护仿真精度的方法  

A Method of Improving the Accuracy of DFIG Electromechanical Transient Model Considering Crowbar Protection

作　　者：訾鹏[1] 周孝信[1] 安宁[1] 侯俊贤[1] 田芳[1] 张石[1] 李新[2] 

机构地区：[1]中国电力科学研究院,北京市海淀区100192 [2]山东电力调度中心,山东省济南市250001

出　　处：《中国电机工程学报》2015年第6期1322-1328,共7页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2013CB228203);国家863高技术基金项目(2011AA05A103)~~

摘　　要：提高双馈式风力发电机(doubly-fed inductiongenerator,DFIG)机电暂态模型精度的关键在于对各种类型故障的模拟,如何在对称故障机端电压跌落中等幅度或不对称故障机端电压跌落较深等工况下,建立准确的撬棒电阻(crowbar)保护模型是DFIG机电暂态模型故障模拟的难点。提出一种提高DFIG机电暂态模型crowbar保护仿真精度的方法。首先,建立DFIG感应电机5阶数学模型,以保留转子电流基频分量作为故障下crowbar保护的动作依据;其次,基于动态相量法,提出5阶感应电机模型与机电暂态电力网络的接口算法;最后,在crowbar控制器机电暂态模型中引入转子负序电流补偿,以模拟严重不对称故障下crowbar保护持续投入,恶化系统电压的情况。以华锐1.5 MW DFIG机组为例,分析了两种工况下的运行特性,仿真结果与实测曲线一致,表明所提方法可准确模拟crowbar保护的动作过程,提高了DFIG机电暂态模型仿真的精度。This paper presented a method of improving the accuracy of doubly-fed induction generator （DFIG） electromechanical transient model under various grid fault conditions. A more accurate modeling of crowbar protection was confirmed to be the major difficulty when the terminal voltage dips to moderate range during symmetrical fault or lower range during unsymmetrical fault. Firstly, the 5th-order induction generator model was introduced, which considers the fundamental frequency components of the rotor current as the triggering crowbar basis during faults. Then the interface algorithm between the 5th-order induction generator model and electromechanical transient transmission network model was proposed based on dynamic phasor theory. Finally, the rotor negative-sequence current was compensated in the electromechanical model of crowbar controller in order to simulate the long time use of crowbar protection and its deterioration to system voltage under severe unsymmetrical fault. Taking Sinovel 1.5MW DFIG as an example, simulation results show that the proposed method is able to simulate the dynamic performance of crowbar under special operating conditions. As a result, the accuracy of DFIG electromechanical transient model is improved.

关 键 词：双馈式风力发电机 机电暂态模型 撬棒电阻 低电压穿越 电力系统暂态稳定 

分 类 号：TM76[电气工程—电力系统及自动化]