【作者】 刘大刚；

【导师】 龚春英；

【作者基本信息】 南京航空航天大学 ， 电力电子与电力传动， 2009， 硕士

【摘要】 本文以两级式小功率三相航空静止变流器为主要研究对象,结合小功率逆变电源的特点,针对效率和小型化的问题,在深入理解各种拓扑特点的基础上,选择LLC谐振变换器为前级直直拓扑,高效可靠的三相双Buck逆变器为后级电路,并重点对双Buck电路作了深入的研究。在简单介绍了几种谐振变换器的工作特性后,分析了LLC谐振变换器的工作原理,给出了LLC谐振变换器的谐振参数计算方法以及500W半桥LLC电路的设计实例,并进行了实验验证。实验结果表明,在本课题中从空载到满载LLC谐振电路都能实现零电压开通,变压器副边整流二极管可以实现零电流关断,实验结果表明该电路具有较高的效率。双Buck逆变器是一种高效率的,高可靠性的电路,它不存在桥臂直通的问题,并且续流管和功率管可以分别单独优化设计。本文在介绍双Buck逆变器工作原理的基础上,研究了开关管工作频率和电路中输入电压、滤波电感及电流滞环宽度之间的关系,并提出了一种可以提高逆变器短路时电路可靠运行的方法,给出了仿真和实验验证。针对逆变器的两个滤波电感占电路体积重量大的问题,对逆变器两滤波电感进行了磁集成技术的研究。介绍了几种磁集成方法,并提出了一种新的磁集成方法。最后将两级联调,实现整机高效、稳定、可靠的运行。更多还原

【Abstract】 The two-stage low power three-phase Aeronautical Static Inverter (ASI) is researched in this thesis. With the purpose to improve overall efficiency and realize low profile, the LLC resonant converter which has the characteristic of simple and high efficiency is employ as the front-end and the dual buck inverter which has the merits of high efficiency and high reliability is selected as the second stage, after taking a comprehensive investigation of different topologies and constructs.The characteristics of several resonant converters are briefly introduced and the operation principles and characteristics of LLC resonant converter are analyzed. On presenting the methods of calculating the resonant parameters of the LLC resonant converter, a prototype of 500W half bridge LLC resonant converter is designed. Experimental results show that this circuit has a high efficiency in terms of zero-voltage turn-on of the main switches and zero-current turn-off of the secondary rectifier diodes are realized from no load to full load.Compared with conventional half-bridge inverter, the dual buck inverter (DBI) overcomes the short-through problem, which greatly improves the overall reliability. Besides, the power switches and the power doides can be chosen separately and optimized designed, which results in higher overall efficiency. Based on the introduction of Dual-Buck Inverter, this thesis studies the relationship between operating frequency of switching tube and the circuit’s input voltage, filter inductance and current hysteresis bandwidth. Then, a method of improving the inverter’s reliability in short-circuit protection mode is proposed, and simulation and experimental results verify its feasibility. With the purpose to overcome the drawback that the two filter inductors share a large proportion of the weight and volume of the inverter, integrated magnetism technology is researched. Several magnetics integrated techniques are introduced, and a new method is offered by this paper. However, none of those methods can effectively reduce the volume and weight of the inductors except that the new proposed scheme can only take effect under specifically conditions. At the end, two stages of the ASI is tested together to achieve high efficiency, stable and reliable operation.更多还原