并网双馈感应风力发电机组暂态特性及其影响因素研究

发布时间：2018-01-12 10:30

本文关键词：并网双馈感应风力发电机组暂态特性及其影响因素研究　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：风力发电是我国最有发展潜力和发展前景的新能源发电方式。风力发电在世界各国呈现出迅猛增长的态势,现有风电场中双馈感应风力发电机(DFIG)是主流机型。由于双馈感应发电机的结构不同于传统的同步和异步电机,所以现有的故障特性分析方法不再适用。目前又尚未形成成熟的双馈感应发电机组故障分析方法与解析计算模型,造成继电保护整定计算困难。本文首先详细分析了双馈风力发电机稳态运行原理和低电压穿越运行的改进措施,推导建立了双馈感应发电机基于空间矢量的正、负序数学模型,然后,通过数学解析的方法,在考虑机组初始运行状态的基础上,详细推导了电网发生对称与不对称电压跌落情况下,DFIG的定子侧短路电流的解析表达式,并分析了短路电流中的频率成分及其幅值。继而,针对撬棒保护电路对故障严重程度带有不同的动作延时的特点,将整个故障过程分成两个阶段,分别求解两个阶段的短路电流解析式,据此分析了撬棒保护的动作时间对DFIG短路电流特性的影响。最后,研究了影响短路电流频率成分及其幅值的因素。本文重点分析了双馈感应发电机组的暂态故障特性及其影响因素,当电网发生故障时,对DFIG的故障机理及暂态特性展开了较为深入的研究,在仿真分析的基础上进一步向故障机理及故障量计算方法方向延伸,从假定电网故障下DFIG撬棒保护电路瞬时动作向实际情况中的撬棒保护电路根据故障类型延时动作情况进行了拓展,所提出的故障量计算方法物理意义明确,计算结果准确,为研究大规模风电并网下现行继电保护的适用性的研究及新型继电保护原理的提出提供了理论支撑。
[Abstract]:Wind power generation is a new energy power generation way of China ' s most developing potential and development prospect . Wind power generation has a rapid growth trend in the world . The double - fed induction wind power generator ( DFIG ) in the existing wind farm is the mainstream . As the structure of the double - fed induction generator is different from the traditional synchronous and asynchronous motor , the existing fault characteristic analysis method is no longer applicable . At present , the fault analysis method and the analytical calculation model of the mature double - fed induction generator set have not yet been formed , and the relay protection setting calculation is difficult . This paper first analyzes the steady - state operation principle of doubly - fed wind - driven generator and the improvement measures of low - voltage ride - through operation , deduces the mathematical model of positive and negative - sequence of double - fed induction generator based on space vector , and analyzes the frequency component and its amplitude in the short - circuit current . In this paper , the transient fault characteristic of doubly - fed induction generator unit and its influencing factors are analyzed , and the fault mechanism and transient characteristics of DFIG are studied in detail based on the simulation analysis . The fault calculation method is extended in the direction of fault mechanism and fault calculation method . The proposed fault calculation method has definite physical meaning and accurate calculation result , which provides theoretical support for the study of the applicability of the current relay protection in large - scale wind power grid and the new relay protection principle .

【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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