摘要随着电力电子技术的广泛应用与发展,供电系统中添加了大量的非线性负载,引起电网电压、电流的畸变,导致电力污染,实现“绿色”电能变换成为目前电力电子技术研究的重点之一。在众多谐波治理措施中,使用PWM整流器来调节网侧功率因数,实现能量双向流动这一主动改善电能质量的技术得到了深入的研究和发展。本文基于三相两电平PWM整流器结构,对PWM整流器的控制策略进行了研究。78821
PWM整流器的工作原理及数学模型是实现整流器控制的基础。本文分析了PWM整流器各种工作状态的工作原理,基于开关函数和占空比两种描述方法建立了PWM整流器的数学模型。
对PWM整流器的有效控制是实现其改善电网质量的关键技术。本文重点分析了滞环电流控制和电流前馈解耦控制两种控制策略,并采用电压控制外环和电流控制内环组成的双闭环控制系统,而且对控制器的参数进行了设计,为PWM整流器的控制奠定了理论基础。
最后运用MATLAB/Simulink构建了三相VSR仿真平台,对实验结果进行分析,证明了控制策略的正确性。
毕业论文关键词:PWM整流器; 数学模型; 控制策略; 仿真
Abstract Recent years, power electronic devices have been used wildly used in various industrial applications as essential modules。 A large part of these facilities are composed of diodes or thyristors, which bring severe harmonics pollution to the power grid。 The "green "converter of power has become the study key point of power electronic technology。 Among the methods of harmonic restraining, the technoogy of using PWM rectifier, which can modulate the grid power factor, emplement the bidirectional transmission of power and improve the power quality actively has gotten in-depth study and development。 This paper studied on the control strategy of rectifier based on the structure of the structure of three phase PWM rectifier。
The working principle and mathematic model of PWM rectifier is the base of rectifier's control。 This paper analyzed the working principle of PWM rectifier at every work state, and built the AC mathematic model of PWM rectifier based on the switching function and duty ratio。
The efficient control of PWM rectifier is the key technology of improving grid quality。 This paper analyzed the two control strategy of hysteresis current control and feed-forward decoupled current control, and designed the parameter of the controller, and settled the theory base of the PWM rectifier's control。
A three-phase VSR simulation platform is built with Simulink software, and the simulation results prove the correctness of the control strategy。
Keywords:PWM rectifier; mathematic model; control strategy; simulation
目 录
1 绪论 1
1。1PWM整流器概述 1
1。2研究PWM整流器的意义 1
1。3PWM整流器的研究现状 2
1。4本课题研究内容 3
2 PWM整流器的工作原理、拓扑结构以及数学模型 4
2。1PWM整流器的工作原理 4
2。2PWM整流器拓扑结构 5
2。3三相VSR一般数学模型 9
2。3。1采用开关函数描述的VSR一般数学模型 10
2。3。2采用占空比描述的VSR一般数学模型 11
2。4基于两相αβ(静止)坐标系的数学模型