【作者】 谢秀镯；

【导师】 戚栋；

【作者基本信息】 大连理工大学 ， 电工理论与新技术， 2007， 硕士

【摘要】 高频开关电源系统具有体积小、重量轻、高效节能、输出纹波小等优点，现已开始逐步成为现代通信设备的新型基础电源系统。本文针对目前通信电源系统中模拟控制方法所存在的控制电路结构复杂，一旦设计完成控制策略就不能改变等固有缺点，采用基于DSP的数字控制方式，设计了一款48V／50A的通信高频开关电源，利用小信号模型，建立电压环与电流环双环控制结构，直接生成数字PWM波形，经脉冲变压器隔离，驱动主电路与功率因数校正电路的功率开关管，较好的克服了以上缺点。本文在研究中，利用了软开关技术以提高电源转换效率，采用了全桥移相控制ZVSPWMDC／DC变换器作为电源的主变换电路，分析了全桥移相控制变换器的工作原理及各个时刻的电路特征，并针对全桥移相控制变换器副边占空比丢失的问题，结合当前采用的解决方案，提出了保留高频变压器原边串联的谐振电感以及在滞后臂处增设辅助谐振网络，分析了该结构的工作原理，从而实现超前臂和滞后臂开关管的零电压开关。本文按照高频开关电源的设计步骤，对主要元器件进行了参数的计算以及选型，利用PSpice软件对所设计的主电路进行了仿真分析以及参数优化。提出了一种新颖的基于DSP的数字化移相脉冲生成办法，该方法充分利用DSP内部的全比较资源，产生的脉冲经过脉冲变压器隔离，直接驱动主电路以及有源功率因数校正电路的功率开关管。并建立了移相全桥变换器的小信号模型，给出了该系统的传递函数，利用Matlab进行Bode图的绘制，证明所建立的电压环与电流环双环控制系统是稳定的。同时介绍了功率因数校正电路，重点分析了两级有源功率因数校正的工作原理，并给出了Boost电路的传递函数，并给出了基于Matlab／Simulink的仿真结果，针对数字控制中的采样值，分别设计了有源功率因数校正电路的输入电压、输入电流和输出电压的采样电路。本电源的输出电压为48V，功率为2400W，开关频率为100KHz，纹波系数不大于±0.2％，电源效率不低于88％，功率因数不低于0.99。更多还原

【Abstract】 High frequency switch mode power supply, which has the advantages of light, high efficiency and small output voltage ripple, now has been applied step by step in the new type power system of modern communication devices. This thesis focuses on the full digital control which is based on digital signal process (DSP). A communication switch mode power supply (SMPS) with the output 48V/50A has been designed. By using the small signal mode, we have built the two circle loops which contain the voltage loop and the current loop in order to generate the digital pulse-width modulation (DPWM). The full digital control system could overcome these disadvantages that analog system has.During the research, transform efficiency of the power supply have been increased by using soft switching technology. And the structure of full-bridge phase-shift control zero-voltage switching pulse-width modulation (FB-PS-ZVS PWM) has been adopted as the main transition circuit of power supply. Combined with the current methods, a new solution, including adding the resonant inductance to the primary side of the transformer and assistant-resonant network, has been put forward to making up the duty circle lost of the transformer’s second side. The operate principle has been introduced.According to the design-process of high-frequent switch mode power supply, this thesis has introduced the selection of the main elements. The main circuit has been optimized by using PSpice. A new method, which is making full use of the DSP’s source, has been proposed to produce the digital phase-shift pulse. The thesis has built the small signal mode of the full-bridge phase-shift converter and its transfer function. Meanwhile, the power factor correct circuit (APFC) has also been discussed, especially on two-stage active power factor correction circuit. The results of simulation analysis have been proposed, which is based on Matlab/Simulink. And the sample circuits of input voltage, input current and output voltage of the APFC have also been built.The power supply has the parameters listed as below:Output voltage: 48V, output power: 2400W, switching frequency: 100KHz, ripple modulus: within 0.2%, efficiency: higher than 88%, power factor: higher than 0.99.更多还原