电压跌落下风力发电机传动链动态特性分析

发布时间：2018-04-01 16:29

本文选题：低电压穿越　切入点：双馈风力发电机组　出处：《华北电力大学》2017年硕士论文

【摘要】：随着大气污染的不断加剧,风能的开发和利用在国家的能源战略地位越来越重要。风力发电在电网中占的比例越来越大,国家电网对风力发电机组提出了低电压穿越的特性要求,风力发电机组的安全稳定运行面临新的挑战。针对低电压穿越条件下双馈风力发电机组机电耦合问题,研究电压跌落下风力发电机组传动链动态响应特性,对于保障双馈风力发电机及电网运行安全具有重要意义。为准确的探究并网双馈风力发电机组机电耦合作用,在分析双馈风力发电机组基本特性的基础上,分别建立了双馈风力发电机组传动链及双馈风力发电机组的数学模型。在传动链建模时,考虑到风力机和发电机间的传动轴的柔性,建立了二、三、四、五个质量块的模型;阐述了双馈风力发电机组在不同质量块下的数学模型,并描述了双馈风力发电机组运行状态与功率之间的关系。基于PSCAD平台对其进行建模仿真,建立了不同质量划分条件下的1.5MW双馈风力发电机组机-电-网仿真模型,从刚度系数、互阻尼、自阻尼三个因素上分析了在电压跌落时对传动链的波动的影响。仿真结果表明,刚度系数越小振荡越激烈,互阻尼越大,波动幅值越小,自阻尼越大,传动效率越低。等效为五质量块模型的传动轴系更能够精确的反应系统的动态特性。最后针对电网电压跌落下双馈风力发电机组的动态响应特性进行分析。对不同电压跌落深度的仿真分析表明,电压跌落深度越大,传动链被激起的波动幅值越大,恢复到平衡值所需要的时间变长。对跌落程度相同条件下不同质量块模型仿真分析结果表明,不同质量块传动链模型对双馈风力发电机组的无功功率等动态特性影响不大,但是对转矩、转速等有较大影响。
[Abstract]:As air pollution intensifies, the development and utilization of wind energy plays an increasingly important role in the country's energy strategy. The State Grid has put forward the characteristic requirements of low voltage traversing for wind turbines, and the safe and stable operation of wind turbines faces new challenges. In view of the electromechanical coupling problem of doubly-fed wind turbines under low-voltage traversing conditions, a new challenge is presented. It is of great significance to study the dynamic response characteristics of wind turbine transmission chain under voltage drop to ensure the safety of doubly-fed wind turbine and power grid. Based on the analysis of the basic characteristics of the doubly-fed wind turbine, the mathematical models of the transmission chain of the doubly-fed wind turbine and the double-fed wind turbine are established respectively. Considering the flexibility of the drive shaft between the wind turbine and the generator, the model of two, three, four and five mass blocks is established, and the mathematical model of the doubly-fed wind turbine under different mass blocks is expounded. The relationship between operation state and power of doubly-fed wind turbine is described. Based on modeling and simulation of doubly-fed wind turbine generator set based on PSCAD platform, a simulation model of 1.5MW doubly-fed wind turbine generator generator with different quality partition is established, which is based on stiffness coefficient. The effects of mutual damping and self-damping on the fluctuation of transmission chain during voltage drop are analyzed. The simulation results show that the smaller the stiffness coefficient is, the more intense the oscillation is, and the greater the mutual damping is, the smaller the fluctuation amplitude is, the greater the self-damping is. The lower the transmission efficiency is, the more accurate dynamic characteristics of the system can be obtained by the transmission shaft system equivalent to the five-mass block model. Finally, the dynamic response characteristics of the doubly-fed wind turbine under the voltage drop of the power grid are analyzed. The simulation analysis of the same voltage drop depth shows that, The greater the voltage drop depth, the greater the amplitude of the fluctuation of the transmission chain, and the longer the time needed to recover to the equilibrium value. The simulation results of different mass block models under the same drop degree show that, Different mass block transmission chain models have little effect on the dynamic characteristics such as reactive power of doubly-fed wind turbine, but have great influence on torque, speed and so on.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM614

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