大功率移相全桥同步整流电源关键技术的研究

发布时间：2018-04-29 13:20

本文选题：同步整流 + 移相全桥　；参考：《北京交通大学》2017年硕士论文

【摘要】：近些年,大功率开关电源在工业生产中的应用已越来越广泛,如有色冶炼、电解电镀、高频加热等。这些行业都是用电大户,即使电源效率只提升1%,也能带来巨大的经济效益。传统大功率开关电源采用二极管整流,在大电流输出条件下,其导通压降会带来巨大损耗,严重制约了电源功率等级和效率的提升。同步整流采用通态电阻极低的MOSFET替代二极管整流,可减小整流损耗,提升电源效率,是一种极具工程应用价值的技术。目前,同步整流研究的热点大多在小功率场合,大功率场合研究应用还不够成熟。基于此,本文就同步整流技术在大功率开关电源中的应用做出了研究。首先,本文从两个方面研究了移相全桥同步整流电路的基本原理:一是研究了移相全桥同步整流电路的运行模态,分析了该拓扑的特点和常见问题;二是用三端PWM开关模型法研究了其数学模型,给出了小信号等效电路,并在此基础上得出相关传递函数,最后对系统进行了闭环设计。接着,本文就同步整流侧的应用问题进行了研究。一是同步整流侧损耗优化问题,从MOSFET损耗模型、小功率场合损耗优化分析、大功率场合下损耗优化分析三个方面进行了研究;二是同步整流侧并联均流的研究,通过仿真研究了影响MOSFET并联均流性的因素以及变压器原副边结构对电源均流性的影响,提出了一些提高均流性的建议。然后,本文就大功率移相全桥同步整流电源系统的开发做出了详细的分析,包括功率主电路的设计和数字控制系统的设计。最后,本文基于前面的分析研制了一台2800A/15V的大功率移相全桥同步整流开关电源,并通过实验验证了该电源的稳定性与高效率。
[Abstract]:In recent years, high power switching power supply has been widely used in industrial production, such as non-ferrous smelting, electroplating, high-frequency heating and so on. These industries are large users of electricity, even if the power efficiency only increase by 1, it can bring huge economic benefits. The traditional high power switching power supply uses diode rectifier. Under the condition of high current output, its on-voltage drop will bring huge losses, which seriously restricts the power level and efficiency of the power supply. Synchronous rectifier adopts MOSFET with very low on-state resistance instead of diode rectifier, which can reduce the rectifying loss and improve the power supply efficiency. It is a very valuable technology for engineering application. At present, the research focus of synchronous rectifier is mostly in small power field, and the application of high power field is not mature enough. Based on this, this paper studies the application of synchronous rectifier technology in high power switching power supply. Firstly, this paper studies the basic principle of phase-shifted full-bridge synchronous rectifier circuit from two aspects: first, the operating mode of phase-shifted full-bridge synchronous rectifier circuit is studied, and the characteristics and common problems of the topology are analyzed. Second, the mathematical model is studied by using the three-terminal PWM switch model method, and the small signal equivalent circuit is given. On the basis of this, the correlation transfer function is obtained. Finally, the closed-loop design of the system is carried out. Then, the application of synchronous rectifier side is studied in this paper. The first is the optimization problem of synchronous rectifier side loss, which is studied from three aspects: MOSFET loss model, low power situation loss optimization analysis, high power situation loss optimization analysis, and synchronous rectifier side parallel current sharing research. The factors affecting the parallel current sharing of MOSFET and the influence of transformer side structure on the current sharing of power supply are studied by simulation, and some suggestions to improve the current sharing performance are put forward. Then, this paper makes a detailed analysis on the development of the high-power phase-shifting full-bridge synchronous rectifier power supply system, including the design of the main power circuit and the design of the digital control system. Finally, based on the previous analysis, a 2800A/15V high power phase-shifted full-bridge synchronous rectifier switching power supply is developed, and the stability and high efficiency of the power supply are verified by experiments.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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