正弦脉宽调制波SPWM的仿真优化

论文编号:CK121   论文字数:14306,页数:52

摘 要
   
    目前，SPWM（正弦脉宽调制）控制技术已被广泛应用于电力电子逆变电源中。理论上，提高开关频率可以减小逆变电源输出波形的谐波，改善波形质量。但是，开关频率的提高会进一步增加功率器件的开关损耗。在较低的开关频率下，为了降低逆变电源输出波形的谐波畸变，各种SPWM 控制策略相继提出，并被广泛应用。SPWM 的控制就是根据三角载波与正弦调制波比较后的交点来确定逆变器功率器件的开关时刻，如何计算SPWM 的开关点，是SPWM 信号生成中的一个难点，也是当前人们研究的一个热门课题。本文论述了SPWM 控制原理及目前广泛应用的几种采样方法（自然采样、规则采样、不规则采样），运用MATLAB仿真软件对几种采样方法进行仿真，对比分析了这几种采样方法的优缺点及输出电压中的谐波成分，更好的抑制与消除输出电压中的谐波成分，以达到优化的效果。

关键词： 正弦脉宽调制，控制原理，采样方法，MATLAB仿真，谐波分析 

Abstract
 
 At present， SPWM (Sinusoidal Pulse Width Modulation) control technology has been widely used in power electronic inverter. Theoretically， improve the inverter switching frequency can reduce the output waveform of the harmonic and improve the waveform quality. However， switch frequency increases will further increase the switch loss. In the lower switching frequencies， in order to reduce the harmonic distortion of the inverter output waveform. Various of SPWM control strategy is put forward，and have widely application. The control is based on triangle SPWM sine wave after comparing with the carrier to determine the intersection of switch power inverter，how to calculate the switch points is a difficulty in SPWM signal generated， and also a hot research subject in current. This article discusses the principle of SPWM control and the current widely used several sampling methods (natural sampling， Regular sampling， irregular sampling)，use of MATLAB software simulation the several sampling method， comparative analysis of the advantages and disadvantages of these different sampling methods and the output voltage harmonic components， better inhibit and eliminate the harmonic voltage output， in order to achieve optimal effect.
Keywords： Sinusoidal pulse width modulation，Control principle，Sampling method，    MATLAB simulation，Harmonic analysis

目 录

摘要……………………………………………………………………………………………………Ⅱ
Abstract ……………………………………………………………………………………………Ⅲ
1  前言……………………………………………………………………………………………… 1
2  正弦脉宽调制变频器…………………………………………………………………… ……2
    2.1  PWM变频器…………………………………………………………………………………2
    2.2  电压SPWM原理…………………………………………………………………………… 3
    2.3  单极式SPWM ………………………………………………………………………………4
    2.4  双极式SPWM ………………………………………………………………………………7
3  SPWM采样法仿真………………………………………………………………………………10
 3.1  自然采样法仿真 …………………………………………………………………………10
        3.1.1  自然采样法概述 …………………………………………………………………10
        3.1.2  脉冲开关点算法 …………………………………………………………………11
        3.1.3  逆变电路仿真 ……………………………………………………………………15
                    3.1.4  电压谐波分析 ……………………………………………………………………18
    3.2  对称规则采样法仿真 ……………………………………………………………………20
        3.2.1  对称规则采样法概述 ……………………………………………………………20
        3.2.2  脉冲开关点算法 …………………………………………………………………21
        3.2.3  逆变电路仿真 ……………………………………………………………………26
                  3.2.4  电压谐波分析 ……………………………………………………………………29
    3.3  不对称规则采样法仿真 …………………………………………………………………30
        3.3.1  不对称规则采样法概述 …………………………………………………………30
        3.3.2  脉冲开关点算法 …………………………………………………………………31
        3.3.3  逆变电路仿真 ……………………………………………………………………35
                    3.3.4  电压谐波分析 ……………………………………………………………………37
4  总结………………………………………………………………………………………………39
致谢……………………………………………………………………………………………...……40
参考文献 ……………………………………………………………………………………………41
附录……………………………………………………………………………………………………42