三相四桥臂逆变器仿真研究学位论文.docVIP

西安理工大学本科生毕业设计（论文） 毕业设计（论文） 题 目 三相四桥臂逆变器仿真研究 专 业 电气工程及其自动化 班 级 电气084 学 生 陈 明 指导教师 杨 惠 2012 年 陈明：三相四桥臂逆变器仿真研究 西安理工大学本科生毕业设计（论文） 论文题目：三相四桥臂逆变器的仿真 研究 专业：电气工程及其自动化 班级：电气084班 作者： 指导教师： 职称： 答辩日期：2006-06-26 摘 要 随着新能源的快速发展，微电网由于其供电的灵活性和独立性越来越受到研究人员的重视。针对微电网中用户负载的可变性和不平衡的特点，逆变器种类有分裂电容式逆变器电路拓扑、三个单相桥组合逆变器拓扑、三相四桥臂逆变器等电路拓扑。相对于其它抑制负载不平衡的逆变器来讲，三相四桥臂逆变器具有控制灵活、输出电压稳定的特点，受到学者的广泛关注。通过对该电路拓扑采取适当的控制策略，逆变器可以向用户负载提供稳定且对称的三相电压。 本文首先对三相四桥臂逆变器电路拓扑的三维空间电压矢量调制策略做了详细阐述。其次，对三相四桥臂逆变器进行数学建模，分别建立了该电路拓扑在静止坐标系和同步旋转坐标系下的数学模型，就目前提出的几种控制方案进行了分析对比，确定了本文所采用的控制策略，即基于双坐标变换的双环控制策略。 在对控制策略的理论分析基础上，利用PSIM仿真软件对控制方案进行了仿真验证，仿真结果证明了本文所采用控制方案的正确性。 关键词：微电网，三相四桥臂逆变器，对称分量法，不平衡负载 Abstract Along with the rapid development of renewable energy,more and more researchers pay attention to the micro-grid for its advantage of independence and flexible power supply.The four-leg inverter can provide the stable and symmetrical three-phase voltage for the unbalance loads. The four-leg inverter has the feature of flexible control compared with other inverters under the condition of the unbalance loads. Firstly, the four-leg inverter is selected as the research object and its mathematical models are realized on the stationary frame and synchronous rotation reference frame respectively and the three dimensional modulation method based on space voltage vector for the four-leg inverter is discussed in detail .Secondly,the control strategy is decided on the basis of analysis and comparison of the other control strategy, the symmetrical component method is used to abstract the positive sequence,zero sequence and negative sequence for the related voltages and currents the outer voltage loop and inner current loop are utilized to control each sequence based on DC components and the better performance is ensured. Keywords: micro-grid; unbalanced load;three-phase four-leg inverter; symmetrical component method 陈明：三相四桥臂逆变器仿真