分布式微网光伏发电逆变系统的研究

发布时间：2018-07-22 17:25

【摘要】：近年来,随着社会的发展,人们对能源的需求量日益增加,能源危机和环境恶化问题日益凸显,开发新能源刻不容缓。太阳能作为一种极具发展潜能的可再生能源,逐步走进了人们的视野。当前对太阳能的开发利用有很多种,其中具有发展前景的就是光伏发电,其中分布式光伏发电由于其电压等级低,靠近负荷等优点成为人们研究的重点。本文对并网发电进行了系统的研究,设计了一种10kW光伏并网式发电系统并着重分析了并网逆变器的控制策略。首先,本文介绍了光伏发电研究的意义及国内外发展现状,分析了光伏电池的电池特性,在此基础上对光伏电池进行了仿真分析,并重点研究了几种最大功率跟踪的方法,提出了一种改进的MPPT。设计了DC-DC升压模块和DC-AC逆变模块。其中前级DC-DC采用了双Boost升压电路为后级提供稳定的电压,后级DC-AC模块列举了并网逆变器的类型,并确定了三相并网逆变器的拓扑结构,在abc、αβ、dq三个坐标系下分别建立了并网模式下的数学模型,重点分析比较了电压矢量控制和直接功率控制两种控制策略,在电压矢量控制策略中设计了一种基于二阶广义积分的锁相环并对其进行仿真研究,比较了传统锁相与广义积分锁相的优缺点,完成了逆变器的设计,通过仿真对其进行了验证。最后,确定了整个系统的核心采用STM32F051单片机,设计了整个发电系统器件的型号和参数,完成了驱动电路,电流电压采样电路、辅助电源等电路的硬件设计和整体软件实现框图,为以后太阳能改进和成品的实现奠定了基础。
[Abstract]:In recent years, with the development of society, the demand for energy is increasing day by day, the energy crisis and environmental deterioration are increasingly prominent, so it is urgent to develop new energy. As a kind of renewable energy with great potential, solar energy has gradually come into people's view. At present, there are many kinds of solar energy development and utilization, among which photovoltaic power generation has the prospect of development, and distributed photovoltaic generation has become the focus of research because of its low voltage level, close to the load and so on. In this paper, a 10kW photovoltaic grid-connected generation system is designed and the control strategy of grid-connected inverter is analyzed. First of all, this paper introduces the significance of photovoltaic research and its development status at home and abroad, analyzes the characteristics of photovoltaic cells, then simulates the photovoltaic cells, and focuses on several methods of maximum power tracking. An improved MPPT is proposed. DC-DC booster module and DC-AC inverter module are designed. The former DC-DC uses double boost circuit to provide stable voltage for the back stage, the latter DC-AC module enumerates the types of grid-connected inverter, and determines the topology of three-phase grid-connected inverter. Mathematical models of grid-connected mode are established in three coordinate systems of abcand 伪尾 -dq, respectively. Two control strategies, voltage vector control and direct power control, are analyzed and compared. In the voltage vector control strategy, a phase-locked loop based on second-order generalized integral is designed and simulated. The advantages and disadvantages of traditional phase-locked loop and generalized integral phase-locked loop are compared, and the inverter is designed. It is verified by simulation. Finally, the core of the whole system is determined to adopt STM32F051 single chip microcomputer, the model and parameters of the whole power system device are designed, the hardware design and the whole software block diagram of the driving circuit, the current and voltage sampling circuit and the auxiliary power supply circuit are completed. For the future solar energy improvement and the realization of finished products laid the foundation.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615;TM464

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