【作者】 王文彬；

【导师】 王宏；

【作者基本信息】 哈尔滨工业大学 ， 电气工程， 2013， 硕士

【摘要】 开关电源以其优越的性能，经过多年的发展，目前已经取代线性稳压电源，越来越被广泛的应用。由于正激电源具有较高的可靠性和效率而被广泛的应用在航天动力系统、通信电源、计算机电源等各个领域。近年来，随着计算机、微电子等行业技术上的革新，要求有低电压高电流输出的开关电源技术成了各国科研人员研究的重要课题。本文对具有高可靠性的低压大电流直流开关电源进行了深入的研究。本文首先分析比较了几种磁复位方式的优缺点，采用有源箝位磁复位方式实现零电压开通，主要它能够利用箝位电容及开关管的输出电容与变压器绕组的励磁电感发生谐振，创造软开关的条件，减少开关损耗，从而提高电源效率。且在主开关关断期间，箝位开关能够限制主开关两端的电压值，克服了常规硬开关电路中变压器漏感及寄生电容产生的电压尖峰，控制技术用以保证开关电源输出电压电流的稳定，在对不同隔离反馈控制方法对比研究的基础上，设计采用电压控制模式的幅度调制磁反馈电路，说明了其工作原理，并进行了仿真，仿真结果表明该方法能够有效保证电源输出电压稳定，动态特性好，其变压器的隔离方式结构简单，能够有效实现输入输出间的信号隔离，具有较长的寿命和较好的抗辐照能力。为了从理论上对电源的环路进行有效分析，本文建立了有源箝位正激变换器的小信号模型，同时对采用幅度调制磁反馈的环路进行了小信号深入分析，并以此为基础设计了补偿电路。本文最后设计了5V/20A输出的DC-DC电源样机，在实验中对其主拓扑波形、动态特性、纹波测试、效率曲线等进行测试分析，结果表明该样机能够达到各项指标要求，并具有较好的静态特性和动态特性，同时达到了较高的效率和可靠性，说明了本文提出的设计方法切实可行。更多还原

【Abstract】 After years of development, switching power supply has replaced the linearregulated power supply with its superior performance. And it is more and more widelyapplied in almost all fields. The excitation converter due to its high reliability andefficiency are widely used in aerospace system, communication power supply, computerpower supply and so on. In recent years, along with the technology innovation ofcomputer and microelectronics industry, switching power supply with low voltage andhigh current output has became the hot topics in the study by scientific researchpersonnel. In this paper, the high reliability DC-DC power supply with low voltage andhigh current output is made in-depth research.Firstly, this paper compared with the advantages and disadvantages of severalkinds of magnetic reset, and the active clamp magnetic reset method was adopted torealize zero voltage opening. It can use the clamping capacitance, output capacitance ofthe switch tube and the inductance of excitation transformer winding in resonance tocreate the condition of soft switch, reduce the switching loss, so as to improve thepower efficiency. And during the period of the main switch off, clamping switch canlimit the voltage value of main switch, to overcome the leakage inductance of thetransformer in a conventional hard switching circuit and the voltage spike of theparasitic capacitanceControl technology is used to ensure the stability of switch power supply outputvoltage and current. At first, on the basis of analyzing and studying the differentfeedback control methods, and then designs the amplitude modulation magneticfeedback circuit with the voltage control mode, introduces its working principle, andcarries on the simulation. The simulation results show that the method can effectivelyguarantee that the power supply has a stable output voltage and a good dynamiccharacteristic. The transformer isolation method has a simple structure, can effectivelyrealize the signal isolation between the input and output. It also has a long life and agood irradiation resistance. In order to analysis of the power supply loop effectively intheory, this paper builds the model of the active clamp forward, and then makes a smallsignal analysis of the amplitude modulation magnetic feedback. On this basis, thecompensation circuit has been designed. The simulation results show that the loop hasgood amplitude and frequency characteristics.Finally, this paper designs a DC-DC power supply prototype with5V/20Aoutput. Through analysis the experimental waveforms including output voltage andcurrent when load switching, voltage ripple, and tests the efficiency curve, the prototype can meet the requirements of the indicators. A good stability and dynamiccharacteristics can be achieved using the design of this paper, at the same time,achieving a high efficiency.更多还原