风力发电运行控制研究

发布时间：2019-01-04 12:12

【摘要】：随着世界各国越来越重视对可再生能源的应用,特别是在全球能源危机、资源紧缺、环境污染等问题出现时,风力发电将会得到空前发展。众所周知,风力发电清洁无污染,施工建成短,占地面积小,投资比较灵活,具有一定的经济效益和社会意义。正是在这种具有很大利用前景的条件下,各国都加大了对风力发电的投入,包括大量资金的投入、技术人员的培养以及各级政府的鼓励和相关政策的实施,风力发电技术得到空前提高,发电设备也越来越符合质量要求。在当今的风力发电技术中,变频恒速的双馈感应发电系统是其中一主要发展方向。随着单机容量的不断增大,总装机容量规模也越来越大,从而对并网的技术要求也越来越严格。本文主要立足于理论分析,在建立各个子系统仿真模型后,通过matlab仿真分析其运行时控制系统的可行性。本文首先介绍了风力发电在我国的发展趋势及现状,研究了其现实意义,概述了本文研究的内容;然后对双馈感应电机发电系统的结构进行了阐述,分别对其各个组成部分进行了分析,先对风速主要四种关系式进行了简单的描述,包括基本风、随机风、阵风以及阶跃风,分别介绍了四种风速类型的基本形成原理以及相应的数学表达式,并通过建模仿真确定了其准确性;然后阐述了风力机的运行原理,即将风能转换为另一种形式的机械能的旋转装置,其输入的是风速作用于叶片产生的机械能,从而输出机械转矩,利用数学关系式建立了仿真模型;接下来对双馈电机的发电原理进行了理论分析,在空载并网前,双馈电机定子绕组通过并网开关直接与电力网络相连,转子绕组则通过双向电压变频器实现与电力网络能量相互流通,通过坐标变换得到了双馈电机在同步旋转速度dq坐标系下的数学模型,同时再加上一定的控制策略,本文主要应用基于定子磁链定向的矢量控制,对其功率进行解耦控制,从而实现稳定。通过对上述介绍的各个子系统建模,在matlab的simulink中实现对其并网结构模型的建立以及没有矢量控制系统的仿真模型,在设定好各个参数值后,得到了所要研究的仿真曲线;通过对仿真曲线的分析,在包含矢量控制模型时,双馈电机发电系统的输出功率能很好的追踪转子转速,跟随转子转速的变化而变化,而且同时验证了风能利用系数与风力机输出机械转矩的关系。通过分析研究表明,双馈感应电机在运行时通过矢量控制技术能维持很好的输出效果,通过与不存在控制系统的仿真模型曲线对比可以看出,矢量控制技术在控制系统中能得到一定程度的效用,从而验证了控制系统的合理性。
[Abstract]:With more and more attention paid to the application of renewable energy in the world, especially in the global energy crisis, resource shortage, environmental pollution and other problems, wind power generation will be unprecedented development. As we all know, wind power generation is clean and pollution-free, short construction, small area, flexible investment, and has certain economic benefits and social significance. It is under such conditions that there is a great potential for utilization that countries have increased their investment in wind power generation, including the investment of a large number of funds, the training of technical personnel, the encouragement of governments at all levels and the implementation of related policies. Wind power generation technology has been unprecedented improvement, power generation equipment is more and more in line with the quality requirements. In today's wind power generation technology, frequency conversion and constant speed doubly-fed induction generation system is one of the main development directions. With the increasing of single machine capacity, the total installed capacity is becoming larger and larger, so the technical requirements of grid-connected are becoming more and more strict. This paper is mainly based on theoretical analysis. After establishing the simulation models of each subsystem, the feasibility of its run-time control system is analyzed by matlab simulation. Firstly, this paper introduces the development trend and present situation of wind power generation in China, studies its practical significance, and summarizes the contents of this paper. Then, the structure of doubly-fed induction motor power generation system is described, and each component of the system is analyzed. Firstly, four main relations of wind speed are described, including basic wind, random wind, gust and step wind. The basic formation principle of four types of wind speed and the corresponding mathematical expressions are introduced respectively, and the accuracy is determined by modeling and simulation. Then the operating principle of the wind turbine is described, that is, the rotating device for converting wind energy into another form of mechanical energy, which inputs the mechanical energy generated by the wind speed acting on the blade, thereby outputting the mechanical torque. The simulation model is established by using mathematical relations. Then the theory of generating power is analyzed theoretically. Before no load is connected to the grid, the stator windings of the doubly-fed machine are connected directly to the power network through grid-connected switches. The rotor winding is circulated with the power network energy through the bi-directional voltage converter. The mathematical model of the double-fed machine in the synchronous rotation speed dq coordinate system is obtained by coordinate transformation, and a certain control strategy is added at the same time. In this paper, the stator flux oriented vector control is mainly used to decouple its power to achieve stability. Through the modeling of each subsystem mentioned above, the establishment of the grid-connected structure model and the simulation model without vector control system are realized in the simulink of matlab, and the simulation curves are obtained after setting the values of each parameter. Through the analysis of the simulation curve, when the vector control model is included, the output power of the doubly-fed generator can track the rotor speed well and change with the change of the rotor speed. At the same time, the relationship between the wind energy utilization coefficient and the output torque of the wind turbine is verified. Through analysis and research, it is shown that the doubly-fed induction motor can maintain a good output effect by vector control technology in operation, and can be seen by comparing with the simulation model curve of no control system. The vector control technology can get a certain degree of utility in the control system, which verifies the rationality of the control system.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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