双馈风电机组动态建模及应用研究

发布时间：2018-06-30 06:47

本文选题：风力发电 + 双馈感应发电机　；参考：《华北电力大学》2014年硕士论文

【摘要】：随着风力发电行业的迅猛发展,风力发电技术取得了长足的进步,双馈感应发电机以其变速恒频运行特性、能够参与系统的无功功率调节等一系列优势得到了越来越多的青睐。然而,目前双馈机组的动态数学模型不太统一,需要进行深入的研究。近年来,风电机组的单机容量呈不断增大的趋势,大容量的风电场对电网的稳定性影响凸显。双馈风电场接入电力系统后会带来新的小干扰稳定问题。另外,双馈风电机组具有较为复杂的控制系统,模型阶数较高,在风场级的分析时会造成“维数灾”,研究如何对双馈风电机组的数学模型进行准确降阶也显得十分重要。针对目前用于静态稳定分析的双馈机组简化数学模型大多不考虑网侧控制动态的情况,本文首先建立了含网侧控制的双馈风电机组数学模型,并对特征值计算结果进行了对比,发现忽略网侧控制的动态特性会遗漏部分主导模态(弱阻尼衰减模态和振荡模态),直接影响小干扰稳定分析的计算结果的准确性。对于双馈机组接入引发的弱阻尼模态,本文首先计算其对系统矩阵的灵敏度,对灵敏度最高的参数进行优化来提高模态阻尼比,进而改善系统小干扰稳定性。和传统的盲目对所有参数优化方法相比,针对性强,可以大幅减小工作量。最后,基于所建立的双馈风电机组详细的数学模型,本文采用了主导模态分析法提出了不同运行工况下风场级小干扰稳定分析双馈风电机组的降阶模型,并采用时域仿真分析法验证了降阶模型的精确性与适用性。
[Abstract]:With the rapid development of wind power industry, wind power generation technology has made great progress, doubly-fed induction generator with its variable speed constant frequency operation characteristics, can participate in the system of reactive power regulation and a series of advantages have been more and more favored. However, the dynamic mathematical model of doubly-fed generating unit is not uniform at present, so it needs to be studied deeply. In recent years, the single unit capacity of wind turbine is increasing, and the influence of large capacity wind farm on the stability of power grid is prominent. When doubly-fed wind farm is connected to power system, it will bring about a new problem of small disturbance stability. In addition, the doubly-fed wind turbine has more complex control system, and the model order is higher, which will cause "dimension disaster" in the analysis of wind field, so it is very important to study how to accurately reduce the order of mathematical model of doubly-fed wind turbine. In view of the fact that most simplified mathematical models of doubly-fed generating units used for static stability analysis do not consider the dynamics of grid-side control, a mathematical model of doubly-fed wind turbines with grid-side control is established in this paper, and the calculation results of eigenvalues are compared. It is found that some dominant modes (weak damping attenuation mode and oscillating mode) will be omitted if the dynamic characteristics of the network side control are ignored, which directly affects the accuracy of the calculation results of the small disturbance stability analysis. For the weakly damped mode induced by the doubly-fed unit, the sensitivity to the system matrix is first calculated, and the parameters with the highest sensitivity are optimized to improve the modal damping ratio and the stability of the system with small disturbance. Compared with the traditional blind optimization method for all parameters, it has strong pertinence and can greatly reduce the workload. Finally, based on the detailed mathematical model of doubly-fed wind turbine, this paper presents a reduced order model for wind field small disturbance stability analysis under different operating conditions by using dominant modal analysis method. The accuracy and applicability of the reduced order model are verified by time domain simulation analysis.
【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】：TM614

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