基于全桥LLC谐振变换器的基站电源设计

发布时间：2018-01-06 20:33

本文关键词：基于全桥LLC谐振变换器的基站电源设计　出处：《陕西科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：近些年来,开关电源技术得以迅猛发展,主要在于其高效以及高功率密度的优势得到了不断优化和创新,多种拓扑结构的层出不穷。软开关技术在开关电源中的优化应用掀起了业内研究的热潮。全桥LLC谐振开关变换器以开关频率高,开关管损耗小,整体效率高,功率密度高等优点在中大功率场合占据重要的地位。本文采用这种高效率的变换器应用于基站电源,不仅节约能源,而且优化了电源效率。本文对此类LLC谐振变换器的工作原理、主电路结构、高效谐振芯片控制部分和数字控制电路部分都进行了详细的分析。设计了一款分别采用两种控制方式控制的48V/12A的全桥LLC谐振变换器,本文主要工作可总结为五个方面,如下：(1)全桥LLC谐振变换器的拓扑分析及特性研究。本文对全桥LLC谐振变换器的拓扑演变过程和工作原理进行了深入的介绍,并针对此类谐振变换器的频率特性、空载特性和短路特性进行详细的分析研究,对谐振变换器主要参数的选择进行了分析。(2)全桥LLC谐振变换器主电路部分设计。依照本文对LLC谐振变换器制定的各类指标,对此类LLC谐振变换器主电路部分谐振腔参数进行优化设计,其还包括了功率开关管的选取、变压器参数的设计及选取、输出整流二极管选取和输出电容选取等。(3)基于高性能谐振控制器芯片MC33067的控制电路设计。本文采用了高性能谐振控制器MC33067来控制谐振变换器。此芯片主要利用了其自身可以通过改变电流来控制内部压腔振荡器频率的性质调节变换器的工作频率,随后对主电路、外围驱动电路以及芯片自身的参数进行了详细设计从而得到较高质量的输出电压。(4)基于DSP的数字控制电路设计。本文采用的是TI的TMS320F28035作为控制单元,设计了配套的控制电路,给出了DSP实现数字PI控制采样电压和采样电流的算法,详细设计了主程序以及各个子程序。(5) Saber仿真及样机制作。利用Saber2010仿真软件对此变换器主电路拓扑填充必要参数后进行仿真。通过不断调整参数,进行反复仿真,合理地设计了死区时间,避免了直通的发生,解决了空载电压不可调等问题。通过观察仿真结果,分析仿真的可行性,搭建了一款输出为48V/12A的实验样机,效率达到了96%,符合设计要求。本文在分别采用了不同的控制方式来控制全桥LLC谐振变换器,使得谐振变换器获得较高的整机效率,充分发挥了其高功高效,小型化和轻量化的特点。就目前而言,在基站电源系统具有广泛的应用前景。
[Abstract]:In recent years, the technology of switching power supply has been developed rapidly, mainly lies in its high efficiency and high power density has the advantage of continuous optimization and innovation, a variety of topology optimization emerge in an endless stream. The application of soft switch technology in the switching power supply industry set off a research boom. The full bridge LLC resonant converter with high switching frequency and switching tube low loss, high overall efficiency, higher power density advantages in high power applications occupy an important position. This paper adopts the high efficiency converter used in the base station power supply, not only saves energy, but also optimize the power efficiency. In this paper, the working principle of this kind of LLC resonant converter, main circuit structure, resonant control chip and high efficiency the digital control circuit are analyzed in detail. The full bridge LLC resonant converter were used to control a control mode of the two 48V/12A design, this paper The main work can be summarized into five aspects as follows: (1) research on topology analysis and characteristics of full bridge LLC resonant converter. The topology of the full bridge LLC resonant converter, the evolution process and working principle are introduced in detail, and according to the frequency characteristics of such resonant converter, detailed analysis of no-load the characteristics and main parameters of the circuit characteristics, resonant converter selection is analyzed. (2) the main circuit design of LLC resonant converter full bridge. According to various indicators of the LLC resonant converter is developed, to optimize the design of the LLC resonant converter main circuit part of the cavity parameters, which also includes select the power switch, and the selection of design parameters of the transformer, the output rectifier diodes and an output capacitor selection selection. (3) control circuit of High Performance Resonant Controller Chip Design Based on MC33067. This paper adopts the high Can MC33067 resonant controller to control the resonant converter. The working frequency of this chip is mainly used to control the properties of its own internal pressure cavity oscillator frequency by changing the current regulation of the converter, then the main circuit parameters of peripheral drive circuit and chip itself into the detailed design to obtain high quality output voltage (. 4) design of digital control circuit based on DSP. This paper uses TI TMS320F28035 as the control unit and the control circuit matching design, gives the DSP implementation of digital PI control sampling voltage and current sampling algorithm, the detailed design of the main program and subprogram. (5) Saber simulation and prototype using Saber2010 simulation. This software converter main circuit topology parameters necessary for simulation after filling. By adjusting the parameters of the repeated simulation, the rational design of the dead time. Free direct occurrence, solves the problem of no-load voltage is not adjustable. By observing the simulation results, the simulation analysis of the feasibility of building a prototype with 48V/12A output, the efficiency reached 96%, in accordance with the design requirements. This paper in different control methods were used to control full bridge LLC resonant converter. The resonant converter to obtain higher overall efficiency, give full play to the characteristics of high power efficiency, miniaturization and lightweight. Currently, has a wide application prospect in the base station power supply system.

【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM46

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