双PWM变换器.docx

摘要常规功率变换器能实现交流电压幅值、频率和相数的改变，并能改善电能质量，在实际中得到非常广泛的应用。但常见的功率变换器，由于其整流环节不可控，存在网侧功率因数低、谐波含量高等缺点，因而限制了它的应用范围。双PWM变换器采用全控型功率开关器件，并引入PWM控制技术实现对整流部分的控制，能有效地消除变频装置对电网的谐波污染，提高功率因数，实现再生能量向电网回馈。三相双PWM变频电源可分为PWM整流器和PWM逆变器两部分。本文在双PWM变换器拓扑结构的基础上，分析了三相PWM整流器结构及其控制方法和三相PWM逆变器结构及其控制方法。分析了PWM变换器能运行在整流和逆变状态的原理。PWM整流器采用双闭环的控制结构，即电压外环和电流内环。PWM逆变器采用电压滞环比较控制方案实现控制目标。在理论分析的基础上，利用MATLAB simulink仿真工具箱搭建双PWM功率变换器的系统仿真模型，并进行了系统仿真。仿真结果表明能对PWM整流器输出直流电压和网侧输入交流电流进行有效控制,使他们的相位基本一致，三相交流输入的功率因数接近1，PWM逆变器也能实现逆变输出电压的频率和幅值均可调，并且逆变波形为三相标准正弦波。AbstractConventional power converters to achieve AC voltage amplitude, frequency and phase changes in the number and improve power quality, in practice, been very widely used. But the common power converters, because of its links are not controlled rectifier, there is net power factor is low, the disadvantages of harmonic content, limiting its scope of application. Dual PWM converter using full-controlled power switching devices, PWM control technology introduced on the control of rectifier, inverter device can effectively eliminate harmonic pollution on the grid, improve power factor, achieve renewable energy back to the grid. Dual PWM three-phase PWM rectifier inverter power supply can be divided into two parts and the PWM inverter. In this paper, dual PWM converter topology based on the analysis of three-phase PWM rectifier and its control structure and three-phase PWM inverter and its control structure. Analysis of the PWM converter can be run on the principle of state rectifier and inverter. PWM rectifier control with dual-loop structure, the voltage outer and current inner. PWM inverter with voltage hysteresis control scheme to achieve control objectives. Based on theoretical analysis, simulation toolbox using MATLAB simulink build dual PWM power converter system simulation model, and the system simulation. Simulation results show that the energy of the PWM rectifier output DC voltage and AC current in net-side input control, so that they basically the same phase