基于DSP的微网逆变器下垂控制策略研究

发布时间：2018-02-24 14:22

本文关键词： 微网逆变器下垂控制孤岛运行 TMS320F28335　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：社会的进步与发展,促进人们对能源的需求愈来愈大,新能源的研发和使用迫在眉睫。紧跟包含新能源的分布式发电技术的快速发展脚步,人们能从更多的渠道获得能源。而微网的快速发展为其提供了一个很好的契机,在这样的形势下,人们增加了对太阳能、核能、风能等清洁能源的使用。研究微网的运行和调控是其核心技术所在,有效的控制方法可以让微网发挥更大的作用。论文首先简述微网研究的背景及意义、国内外的研究现状和微网的基本概念,并对微网逆变器控制策略做了综述。接下来简述了微网的电路结构及其控制方法,着重探析了下垂控制及其特征。在旋转坐标系下构建逆变器的数学模型,阐述了瞬时无功功率理论,得到正确的功率计算公式。接着,为对电压和电流的相位进行快速精确的跟踪,采用软件锁相环设计。在下垂理论基础上进行下垂控制器设计,设置其参数并构建数学模型。文中探究了传统下垂控制的缺点和不足,对于功率不能均分的问题,采取电压电流双闭环控制策略和虚拟阻抗的方法;针对频率发生偏移的不足,采用基于Sigmoid函数的频率下垂方程。在Simulink平台上进行微网孤岛运行仿真,分别搭建了单台和两台并联逆变器的模型来仿真,得出传统下垂和改进型下垂控制下的波形,对比波形结果显示改进型的下垂控制在功率均分方面表现得更加优秀,同时也改善了频率的偏移并使其维持在一定范围内,检验了所述方法的有效性。最后,论文简述了基于TMS320F28335的微网逆变器系统的硬件构成和软件设计。硬件上主要介绍了主电路、驱动电路和采样电路等设计;软件方面给出了系统主程序、中断子程序和过流保护等流程图。
[Abstract]:With the progress and development of society, people need more and more energy, so it is urgent to develop and use new energy. People can get energy from more sources of energy. And the rapid development of microgrids provides a good opportunity for them, in such a situation, people have increased the amount of solar energy, nuclear energy, The use of clean energy, such as wind energy, is the core technology of microgrid. The effective control method can make microgrid play a greater role. Firstly, the background and significance of microgrid research are briefly introduced. The current research situation and basic concepts of microgrid at home and abroad, and the control strategy of microgrid inverter are summarized. Then, the circuit structure and control method of microgrid are briefly described. The mathematical model of inverter is constructed in rotating coordinate system, the theory of instantaneous reactive power is expounded, and the correct power calculation formula is obtained. In order to track the phase of voltage and current quickly and accurately, the software phase-locked loop is used to design the droop controller based on droop theory. In this paper, the shortcomings and shortcomings of traditional droop control are explored, and the voltage and current double closed loop control strategy and virtual impedance are adopted to solve the problem of unequal power distribution. The frequency droop equation based on Sigmoid function is adopted. The microgrid islanding operation simulation is carried out on the Simulink platform. The single and two parallel inverter models are built to simulate, and the traditional and improved droop control waveforms are obtained. The contrast waveform results show that the improved droop control performs better in the aspect of average power distribution, at the same time, it also improves the frequency deviation and keeps it within a certain range, which verifies the effectiveness of the proposed method. In this paper, the hardware structure and software design of microgrid inverter system based on TMS320F28335 are introduced. The main circuit, driving circuit and sampling circuit are mainly introduced in hardware, and the main program of the system is given in software. Interrupt subroutine and overcurrent protection flow chart.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464;TM727

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