【作者】 梅志伟；

【导师】 沈毅；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2009， 硕士

【摘要】 随着传统的三大化石能源日渐枯竭,绿色能源的开发和利用将会得到空前发展。太阳能作为世界上最清洁的绿色能源之一,其并网发电备受世界各国的普遍关注。而光伏并网逆变器是光伏并网发电系统的核心部件,如何可靠和高质量地向电网输送功率尤为重要,因此在可再生能源并网发电系统中起电能变换作用的逆变器成为了研究的一个热点。本文主要以单相光伏并网逆变器为研究对象,对并网系统的拓扑结构,控制策略,MPPT最大功率点跟踪,孤岛保护等方面做了详细的分析与研究,主要内容有:通过对目前常见的各种逆变系统主体电路拓扑结构进行分析和比较,确定了系统DC-DC-AC的拓扑结构方案。DC-DC环节选择用双并联Boost电路取代高频变压器,提高了系统的效率和减小了设备体积;后级逆变环节选择全桥式结构。选择TMS320F2812高性能定点DSP作为系统主控单元,充分利用DSP强大的运算能力和其丰富的片内外设功能,使硬件电路设计相对简单,而且系统输出具有很好的动态响应。建立太阳能电池等效电路模型,分析太阳能电池输出特性,并在此基础上研究各种MPPT最大功率点跟踪算法。理论分析了产生孤岛效应时电路状态的变化,并提出主被动结合的孤岛保护方法。针对DC-DC和DC-AC两级拓扑结构,分别采用各自独立的控制方案,前级实现MPPT和升压功能,后级控制直流母线电压稳定和使输出电流与电网电压同频率同相位,并通过Simulink仿真验证了控制方案理论上的可行性。根据理论上的分析研究,针对给定指标,设计了系统主体电路和控制电路并进行参数的选择。开发了并网逆变器样机,对其硬件电路及软件程序进行了分模块调试,并给出了实验结果。通过分析实验数据和测试波形,证明了所设计样机系统工作性能可靠,设计思路确实可行。更多还原

【Abstract】 With growing depletion of the three traditional fossil energy,the utilization of the green energy including solar energy will get unprecedented development. Solar energy is one of the most clean regeneration energy resource,and its grid-connected system has been cared by the world.Photovoltaic grid-connected inverter is the core component of grid-connected PV system,it is particularly important to transmit the power to grid with high quality and reliability.So Photovoltaic grid-connected inverter is becoming a hot reseach. This paper presents a detailed analysis and research on the topologies of grid-connected system, control strategy, maximum power point tracking, and Gudao protection ,the main content are:By analyzing and comparing a variety of the current commom circuit topologies, the DC-DC-AC topology program is adopted in this dissertation.In the DC-DC part,a dual parallel links boost circuit is choosed to replace a high-frequency transformer circuit to improve the efficiency and reduce the volume of equipment,and the next structure is full-bridge.Choosing the high-performance fixed-point DSP TMS320F2812 as the control unit ,using its powerful DSP computing power and peripheral functions,so that the hardware design is relatively simple ,and the system output has a very good dynamic response.It establishs the solar cell equivalent circuit model ,analysis the output characteristics of solar cell,and study a various of algorithms of the maximum power point tracking.Then it analysis the changes of island effect, and propose a method of island protection with active and passive combined.For the DC-DC and DC-AC two-tier topology,a separate control program is presented.The function of the former class is to boost and achieve the maximum power point.The simulink simulation indicates the feasibility of control theory.According to theoretical analysis and sign specifications for the system,this paper gives the system the main circuit and control circuit and the choice of parameters.The prototype of grid inverter is developed, the hardware circuits and software programs have been sub-module testing, and experimental results are given. By analyzing the experimental data and test waveforms, it demonstrates that the prototype system is reliable and practical.更多还原