微型光伏并网逆变器系统设计

发布时间：2018-02-27 21:00

  本文关键词： 微型逆变器 交错反激拓扑 安规保护 电流调制算法 MPPT算法 孤岛算法 软件锁相算法 电力局域网 自适应网络模型　出处：《上海交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着工业社会的发展,人类对能源需求进一步增加,煤、石油和天然气作为常规能源,占有绝地的比重。但是化石能源储存量有限,越来越满足不了经济发展的需求。人类为争夺能源而爆发的局部冲突甚至国家战争屡见不鲜;另一方面,化石燃料的大量消耗,加剧了环境污染,恶化了地球生存环境,因此必须发展可持续的能源,缓解当前能源危机。太阳能作为全球最清洁的能源,受到各国政府的重视,各国政府已经针对太阳能制定了光伏发展战略,鼓励人们开发利用光伏发电。微型逆变器作为光伏发电系统的核心部件,显著地提高了整个发电系统的效率,有效的解决了传统集中式逆变器面临的阴影和热斑问题,系统安装既方便又灵活,真正实现组件级最大功率点跟踪。因此具有极大的商业价值和实用价值,在光伏逆变系统中独树一帜。本文首先介绍世界各国光伏发展政策和当前太阳能电池技术发展趋势,重点分析了太阳能光伏并网系统三种主流解决方案;针对微型光伏并网逆变器的硬件设计,本文采用高效的交错反激变换器拓扑结构,给出微型光伏并网逆变器核心模块的硬件设计,从安规隔离角度将微型并网逆变器分为原边系统和副边系统,分别就主功率拓扑、控制回路和辅助电源回路给出了工作原理分析和硬件设计方案;与硬件系统相对应,微型光伏并网逆变器软件设计也分为原边系统设计和副边系统设计两个部分。针对微型光伏并网逆变器原边系统设计,详细给出了电流开环模式下微型逆变器DCM算法原理,提出了自适应BCM算法,实现微型逆变器高效的电流调制,显著地降低了电流谐波分量;在分析了微型逆变器系统中光伏电池PV工作特性的基础上,结合经典的扰动观察法控制思想,提出了基于bang-bang控制思想的改进的MPPT算法,不需检测直流电流也能达到很好的动态响应和稳态精度;在研究Sandia主动孤岛算法优缺点的基础上,提出了基于频率跳变的Sandia主动孤岛算法,提高了孤岛发生时故障检测的灵敏度。针对微型逆变器副边系统设计,在研究d-q同步锁相算法工作原理的基础上,提出了基于bang-bang控制的d-q软件锁相算法,实现与电网的精确同步;针对电力局域网的特点,提出了基于电力线载波通信的自适应网络模型,并给出微型逆变器副边网络地址获取算法,实现了分布式网络通信和组件级监控;在综合软硬件设计的基础上,研制一台250W微型光伏并网逆变器实验样机,给出了主要算法的测试波形;最后对微型光伏并网逆变器当前需要解决的问题和今后发展方向给出了一些个人建议。
[Abstract]:With the development of industrial society, human demand for energy has increased further. Coal, oil and natural gas, as conventional sources of energy, account for a large proportion of the total. But fossil energy stocks are limited. The local conflicts and even national wars that have broken out to fight for energy are common. On the other hand, the massive consumption of fossil fuels has aggravated environmental pollution and worsened the living environment of the earth. Therefore, it is necessary to develop sustainable energy and alleviate the current energy crisis. Solar energy, as the cleanest energy in the world, has attracted the attention of the governments of all countries, which have formulated a photovoltaic development strategy for solar energy. As the core component of photovoltaic power generation system, micro-inverter can significantly improve the efficiency of the whole power generation system and effectively solve the problems of shadow and heat spot faced by the traditional centralized inverter. The installation of the system is convenient and flexible, and the component level maximum power point tracking is realized. Therefore, it has great commercial value and practical value. This paper first introduces the development policy of photovoltaic in the world and the current development trend of solar cell technology, focusing on the analysis of three main solutions of solar photovoltaic grid-connected system; Aiming at the hardware design of miniature photovoltaic grid-connected inverter, this paper presents the hardware design of the core module of micro-photovoltaic grid-connected inverter by adopting efficient topology structure of interleaved flyback converter. The miniature grid-connected inverter is divided into primary side system and auxiliary side system from the angle of safety isolation. The working principle analysis and hardware design scheme of main power topology, control loop and auxiliary power supply circuit are given respectively, which correspond to hardware system. The software design of miniature photovoltaic grid-connected inverter is also divided into two parts: primary side system design and auxiliary side system design. Aiming at the design of the original edge system of miniature photovoltaic grid-connected inverter, the principle of DCM algorithm for miniature inverter in open-loop mode is given in detail. An adaptive BCM algorithm is proposed to realize the efficient current modulation of the miniature inverter, which can significantly reduce the harmonic component of the current, and on the basis of analyzing the PV characteristics of the photovoltaic cell in the miniature inverter system, Combined with the classical disturbance observation control idea, an improved MPPT algorithm based on bang-bang control is proposed, which can achieve good dynamic response and steady-state accuracy without detecting DC current. On the basis of studying the advantages and disadvantages of Sandia active islanding algorithm, an improved MPPT algorithm is proposed. An active islanding algorithm for Sandia based on frequency hopping is proposed, which improves the sensitivity of fault detection when the isolated island occurs. For the design of auxiliary side system of miniature inverter, the working principle of d-q synchronous phase-locking algorithm is studied. In this paper, a d-q software phase-locking algorithm based on bang-bang control is proposed to realize precise synchronization with the power network, and an adaptive network model based on power line carrier communication is proposed according to the characteristics of power LAN. The algorithm of obtaining sub-side network address of miniature inverter is presented, which realizes distributed network communication and component-level monitoring. On the basis of comprehensive software and hardware design, an experimental prototype of 250W miniature photovoltaic grid-connected inverter is developed. The test waveforms of the main algorithms are given, and some personal suggestions are given for the problems that need to be solved and the future development of the miniature photovoltaic grid-connected inverters.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464
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本文编号：1544298