导　　师： 程红丽

学科专业： 080902

授予学位： 硕士

作　　者： ;

机构地区： 西安科技大学

摘　　要： DC//DC变换器是一种时变非线性系统。电路参数存在许多不确定性，主电路的性能必须满足输入和负载的变化，这些使DC//DC变换器的控制研究变得比较困难。由于传统变换器的控制方法都是基于线性系统理论，通常是采用模拟电路来实现电压或电流的控制。随着电力电子技术和控制理论的发展，对于复杂多变的DC//DC开关电源，传统的控制方法已经无法满足其越来越高的要求；数字控制具有低功耗、灵活多变、易于引入鲁棒性强的现代控制等优点。模糊控制、神经网络、遗传算法等控制方法被广泛应用于DC//DC变换器中，显示出了比传统控制方式更加优越的性能。 直流电源是科学研究中必不可少的供电设备，传统线性稳压器稳压性能好，纹波小，但效率只有35/%~60/%；开关电源效率可高达70/%~95/%，体积小、质量轻，但控制电路复杂，纹波大。目前大部分电源仍然以线性电源为主，特别是用于实验研究的电源设备。 针对上述问题本文将开关电源与线性电源结合起来，采用DC//DC串联LDO的方法，兼顾二者的优点，可以保证输出电压纹波小、连续可调的同时，提高了电源的效率。为了提高整个系统的效率，Buck电路中采用同步续流技术，减小续流二极管上的损耗，并对LDO进行恒压差控制，避免输出电压在宽范围内变化时因LDO输入输出压差增大产生的损耗；在控制策略方面，将传统的PID控制与模糊控制相结合，采用自适应模糊PID控制，改善了电路的动静态性能，达到了满意的控制效果。多项技术的结合使所研制的电源具有绿色环保和智能化的特点。根据所设计电源的技术指标，完成了DC//DC降压型变换器串联LDO的电路设计，及自适应模糊PID控制器的设计，在MATLAB//Simulink环境中建立了自适应模糊PID控制的Buck变换器系统模型，进行了系统仿真， DC//DC converter is a strongly nonlinear, time-varying and uncertain system. Parametersof the circuit there are many uncertainties, the input and load is varied, the main circuitperformance must meet a wide range of input and load changes, which the DC//DC convertercontrol study becomes more difficult, due to the traditional transformation control methods arebased on the linear system theory, which is usually implemented using an analog circuit tocontrol the voltage or current applied to DC//DC converter and the desired dynamic effects cannot be obtained. Switching power supply for the complexity and time-varying, conventionalcontrol methods can not meet their requirements. Digital control with low power consumption,flexible design cycle is short, easy to implement modular management and cluster control,ease of introducing complex and delicate control strategies and so on. Fuzzy control, slidingmode variable structure control, neural networks, genetic algorithms and other controlmethods are widely used in DC//DC converter, showing a more superior than traditionalcontrol method performance. DC power supply is essential for scientific research equipment, traditional linear regulatorregulator performance, the output ripple is small, but the efficiency is only35/%~60/%;switching power efficiency up to70/%~95/%small size, light weight, but the adjustmentelement control circuit complexity, the ripple is large. Currently, most power is still dominatedby linear power, especially the power equipment used for experimental research. This paper will address these issues with a linear power supply switching power supplycombine both the advantages of both, using DC//DC series LDO method, taking into accountthe advantages of both, so that the output voltage ripple small, continuously adjustable. Inorder to further improve the efficiency of the whole system, the synchronous rectificationusing Buck circuit, reducing the freewheeling diode loss. When using constant pressuredifferential control on LDO, avoiding the output vol

关 键 词： 模糊 变换器 变换器

领　　域： [电气工程]