摘要本文研究了一种单级升降压PWM整流电路。与传统的二极管和可控硅整流器相比，三相PWM电压型整流电路具有交流侧输入电流为正弦波且谐波分量小、功率因数接近于1且可调、直流侧电压波动小、能量能双向流动等优点。升降压型三相PWM整流电路由三相PWM整流器与直流斩波电路组合而成，利用斩波电路的特性，通过控制开关器件的占空比来调整输出电压的大小，获得较大的直流电压调节范围。本文采用Cuk电路建立升降压PWM整流电路模型，讨论了电路结构和控制方法，完成了参数设计。在此基础上建立仿真模型，完成计算分析，归纳了电路的工作性能和特点等。该电路可用于电机驱动、新能源并网等领域。87409

毕业论文关键词  三相PWM整流电路  升降压  占空比。

毕业设计说明书外文摘要

Title  Analysis on a Three-Phase PWM Step-up/down AC/DC Converter

Abstract In this paper, a single stage three-phase PWM step-up/down AC/DC converter is studied。 Compared with the traditional rectifiers built with diode and SCR(silicon controlled rectifier),three-phase PWM step-up/down AC/DC converter merits the sinusoidal AC input current and less harmonics, adjustable power factor which can be close to 1, small DC voltage fluctuation and bi-directional energy flow。 Based on fully controllable devices, general three-phase PWM step-up/down AC/DC converter is composed of a three-phase PWM rectifier bridge and a DC chopper。 By using the features of choppers to obtain DC voltage and then by controlling the duty ratios, the output voltage is adjustable within a wider range。Instead of the frequently used buck-boost circuit, a three-phase PWM step-up/down AC/DC converter using the Cuk circuit is investigated。 In this dissertation, the circuit model is established, the structure and the control method are discussed, and the parameters are designed。 Then the simulation model is set up, the calculation and the analysis are carried out。At last, the performance and the characteristics of the circuit are summerized。The circuit can be widely used in motor drive, new energy grid,etc。

Keywords  voltage source rectifier,AC/DC converter, duty cycle。 

目   录

1  绪论 1

1。1  课题背景和研究意义 1

1。2  研究现状 2源-于Y优+尔-论.文:网www.youerw.com 原文+QQ7520^18766

1。3  本论文的主要工作 2

2  升降压PWM整流电路的结构和工作原理 3

2。1  Cuk型升降压PWM整流器的工作原理 3

2。2  电路结构和统一空间矢量的概念 5

2。3  转换器的工作原理 7

2。4  电压增益和等效直流电压占空比 9

2。5  LC 参数的选择 13

2。6 本章小结 14

3  仿真建模与结果分析 15

3。1  降压仿真实验 18

3。2  升压实验部分 20

3。3  本章小结 22

结  论