开绕组BDFG双两电平变流器拓扑结构及控制策略研究

发布时间：2018-01-20 07:52

本文关键词： 无刷双馈风力发电机开绕组共直流母线直接功率控制共模电压抑制　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：在人类追求快速发展经济的过程中,造成了全球性的污染和生态的破坏。风能作为一种无污染、可持续发展的能源走入人们的视野,双馈感应发电机因其可以实现变速恒频的发电,成为了风力发电机的主要机型。无刷双馈发电机继承了双馈感应发电机的优点,还省去了滑环等结构,降低了故障率,尤其适用于海上风力发电场合。本文以国家自然科学基金项目“复合转子开绕组无刷双馈风力发电机及其直接功率控制策略”(项目批准号:51277124)为背景,以无刷双馈风力发电机为研究对象,提出了一种适用于该种发电机的开绕组拓补结构及控制策略。主要研究内容如下:(1)分析了无刷双馈风力发电机的工作原理、三种不同运行方式及其在不同运行方式下的功率流向关系;所研究的无刷双馈风力发电机的转子采用一种具有较强耦合能力的新型混合转子结构,定子的控制绕组设计成开绕组结构。为了建立其等效电路,本文推导了无刷双馈风力发电机在MT旋转坐标系下的数学模型。(2)研究了瞬时功率理论以及直接功率控制原理,直接功率控制策略具有功率响应速度快、计算简单、对发电机参数依赖小等优点,特别适用于风力发电场合;改进传统的直接功率控制策略,以便能够适用于混合转子无刷双馈电机的特殊结构;分析了在开绕组结构下,采用双两电平变流器所产生的空间电压矢量。这些空间电压矢量具有3种不同的幅值,所以本文将其归类为长矢量、中矢量和短矢量,并总结出了每种空间电压矢量在直接功率控制策略中的不同作用效果。(3)分析了在共直流母线开绕组结构中,共模电压和共模电流的产生机理及其危害;针对基于双两电平变流器的混合转子开绕组无刷双馈风力发电系统,提出了一种基于直接功率控制的共模电压抑制控制策略,并采用MATLAB/Simulink软件对所提出的控制方法进行了仿真分析,结果表明这种控制方法可以大大提高了功率控制精度,并能有效抑制系统中的共模电压。(4)以TI公司生产的TMS320F28335DSP芯片为控制核心,设计了一套基于两台四象限变流器的控制系统;搭建了混合转子共直流母线开绕组无刷双馈风力发电机(额定功率为23kW)的直接功率控制系统实验平台,并进行了实验研究,验证了所提出基于直接功率控制的共模电压抑制策略的有效性。
[Abstract]:In the process of human pursuit of rapid economic development, caused global pollution and ecological damage. Wind energy as a non-polluting, sustainable development of energy into the people's vision. The doubly-fed induction generator has become the main type of wind turbine because of its variable speed and constant frequency generation. The brushless doubly-fed generator inherits the advantages of doubly-fed induction generator and saves the structure of sliding ring and so on. Reduced the failure rate. It is especially suitable for offshore wind power generation. In this paper, the project of National Natural Science Foundation "Brushless Doubly-fed Wind Generator with compound rotor Open Winding and its Direct Power Control Strategy" (. Project approval number: 51277124). The brushless doubly-fed wind turbine is taken as the research object. This paper presents an open-winding extension structure and control strategy for the generator. The main research contents are as follows: 1) the working principle of the brushless doubly-fed wind turbine is analyzed. Three different operation modes and their power flow relationship under different operation modes; The rotor of the brushless doubly-fed wind turbine adopts a new hybrid rotor structure with strong coupling ability. The control winding of the stator is designed as an open-winding structure. In order to establish its equivalent circuit. In this paper, the mathematical model of brushless doubly-fed wind turbine in MT rotating coordinate system is derived. The instantaneous power theory and direct power control principle are studied. The direct power control strategy has fast power response speed. Simple calculation and little dependence on generator parameters, which is especially suitable for wind farm. The traditional direct power control strategy is improved so that it can be applied to the special structure of the hybrid rotor brushless doubly-fed machine. This paper analyzes the space voltage vectors which are generated by using double two level converters under open winding structure. These space voltage vectors have three different amplitudes, so this paper classifies them into long vector, medium vector and short vector. The different effects of each space voltage vector in direct power control strategy are summarized. The mechanism and harm of common-mode voltage and common-mode current in the open winding structure of common DC bus are analyzed. A common-mode voltage suppression control strategy based on direct power control is proposed for a hybrid rotor open-winding brushless doubly-fed wind power generation system based on two-level converter. The proposed control method is simulated and analyzed by MATLAB/Simulink software. The results show that this control method can greatly improve the accuracy of power control. A control system based on two four-quadrant converters is designed based on the TMS320F28335DSP chip produced by TI Company. An experimental platform of direct power control system for a hybrid rotor common DC bus open winding brushless doubly-fed wind turbine (rated power is 23kW) is built, and the experimental research is carried out. The effectiveness of the proposed common-mode voltage suppression strategy based on direct power control is verified.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM315

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