光伏逆变器的网控制仿真.doc

毕业论文(设计) 设计(论文)题目： 光伏逆变器的并网控制仿真 指导教师： 2011年6月10日摘 要 世界环境的日益恶化和传统能源的日益枯竭，促使了对新能源的开发和发展。具有可持续发展的太阳能资源受到了各国的重视，各国相继出台的新能源法对太阳能发展起到了推波助澜的作用。其中，光伏并网发电具有深远的理论价值和现实意义，仅在过去五年，光伏并网电站安装总量已达到数千兆瓦。而连接光伏阵列和电网的光伏并网逆变器便是整个光伏并网发电系统的关键。 光伏并网逆变器是将太阳能电池所输出的直流电转换成符合公共电网要求的交流电并送入电网的设备。首先介绍了光伏并网逆变器。其次，本文采用直流电压外环、电流内环的双闭环控制方法，既保证了逆变器输出的静态误差为零，又保证了逆变器良好的输出波形。随后，本文详细讨论了并网过程中的软件锁相环技术，对锁相环电路的组成、工作原理进行了研究。 本文根据逆变器结构的特点，提出了基于DC-AC单级并网逆变器的结构。在DC-AC转换器中，采用输出电流控制，根据正弦脉冲宽度调制的缺点，提出空间矢量脉宽度调制方法对逆变器进行控制，从而提高直流侧电压的利用率，减少谐波。基于SVPWM的控制原理，在MATLAB_simulink上建立系统模型，并进行了仿真实验。仿真结果表明输出电流与电网电压保持同相位，从而证明了原理的可行性。 关键词：光伏发电 并网逆变器 SVPWM 锁相环技术 ABSTRACT The worlds environment is deteriorating and the increasing depletion of traditional energy sources to promote the development of new energy development. Solar energy resources by the countries attach importance to sustainable development,countries have introduced a new energy law has played a role in fueling the development of solar energy. Among them,photovoltaic power generation has far-reaching theoretical value and practical significance,in the past five years alone,the total photovoltaic power plant installation has reached thousands of megawatts. Connected photovoltaic arrays and grid photovoltaic grod-connected inverter is the key to the entire grid-connected PV systems. PV grid-connected inverter solar cell output DC into AC meet the requirements of the public grid and into the power grid equipment. First introduced the PV grid-connected inverter. Secondly,the DC voltage loop and inner current closed-loop control method,both to ensure zero static error of the inverter output,but also to ensure that the inverter output waveform. Subsequently,the detailed discussion of the software phase-locked loop technology and network process,the composition of the phase-locked loop circuit,the working principle of the study. According to the characteristics of the inverter structure,based on the structure of the DC-AC sin