并网型双馈异步发电机奇异诱导分岔型电压崩溃机理

发布时间：2018-08-24 17:27

【摘要】：双馈异步发电机(doubly-fed induction generator,DFIG)中含有各种时间尺度的机械量、电气量与控制量,暂态过程复杂,目前对其暂态电压崩溃研究尚未深入。该文针对DFIG的暂态稳定性问题提出规范化的微分代数方程(differentialalgebraic equations,DAE)模型,并依据DAE的奇异面理论研究风机发生暂态电压崩溃的内部机理。仿真分析表明DFIG不仅会由于状态量移出吸引域而出现典型的动力学失稳,还时常伴随出现2种瞬时的电压崩溃现象,即短路电流激增导致系统状态量接触到网络方程约束产生的奇异面,从而在局部失去代数方程解的唯一性;或由于直流母线电压的快速下降而致使系统无法顺利穿越电压零点。不同于以往同步发电系统中恒功率电源引入造成的系统奇异,DFIG发生失稳的机理主要同其与电网的连接强度密切相关。并通过基于规范化模型的数值仿真验证上述理论分析的正确性。
[Abstract]:Doubly-fed asynchronous generator (doubly-fed induction generator,DFIG) contains mechanical quantities, electrical quantities and control variables of various time scales, and the transient process is complex. So far, the research on transient voltage collapse of doubly fed induction generator (doubly-fed induction generator,DFIG) has not been thoroughly studied. In this paper, a normalized differential algebraic equation (differentialalgebraic equations,DAE) model for transient stability of DFIG is proposed, and the internal mechanism of transient voltage collapse of fan is studied based on the singular surface theory of DAE. The simulation results show that DFIG not only has a typical dynamic instability due to the state shift out of the attraction region, but also often accompanied by two transient voltage collapses. The short circuit current surge causes the system state quantity to come into contact with the singular surface produced by the network equation constraint, thus losing the uniqueness of the solution of the algebraic equation locally, or because of the fast drop of the DC bus voltage, the system is unable to cross the voltage zero point smoothly. The mechanism of DFIG instability caused by the introduction of constant power supply is closely related to the connection strength between DFIG and power grid. The correctness of the above theoretical analysis is verified by numerical simulation based on canonical model.
【作者单位】：电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系);
【基金】：国家自然科学基金项目(51190101) 国家863高技术基金项目(2011AA05A103)~~
【分类号】：TM31

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