三电平电压型逆变器控制策略的研究

发布时间：2018-01-26 15:41

本文关键词： 三电平逆变器正弦脉宽调制 SVPWM 矢量控制　出处：《西南交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：作为多电平逆变电路中最常用的三电平逆变电路,三电平逆变电路与传统的两电平逆变器相比,具有谐波电流小,开关损耗低等优点。三电平逆变器以其优越的性能已经逐步取代传统的两电平逆变器,成为了大容量、中高压电机调速的主要实现方式之一。因此对三电平逆变电路的研究很有意义。本文主要以二极管箝位式三电平逆变电路为主,对它的主电路拓扑结构进行了分析,研究其工作原理,并以此为根据建立了三电平逆变器的数学模型。论文详细分析了二极管箝位型三电平逆变电路的正弦脉宽调制(SPWM)和空间矢量调制(SVPWM)的基本原理、实现方法。对SPWM调制方式采用载波同相、载波反相、载波纵向位移、注入零序分量、注入三次谐波进行对比分析,同时利用傅里叶变换分析输出特性。论文对SVPWM调制方式采用六小扇区和四小扇区方式分别进行说明,对比分析其输出特性,论文还以二极管箝位型三电平逆变电路的拓扑结构为基础,分析了中点电位不平衡的原因,并提出了中点电位调制算法。最后通过Matlab/simulink分别对各种调制方式建立仿真模型,通过对各种方式输出结果的FFT分析,验证了各种调制方法的有效性,对比分析了各种方式的直流电压利用率和输出谐波含量等输出特性。最后论文以目前国内机车牵引传动系统中常用的矢量控制方式为例,主要研究了基于磁场定向控制SVPWM方式的电机调速系统的原理和实现过程。利用Matlab/Simulink搭建牵引逆变器仿真模型,通过对电机启动和制动等的仿真研究,验证了系统的快速的响应特性,验证电机的牵引特性和论文所述控制策略的有效性。
[Abstract]:As the most commonly used three-level inverter in multilevel inverter, three-level inverter has less harmonic current than traditional two-level inverter. With its superior performance, three-level inverter has gradually replaced the traditional two-level inverter and become a large capacity. One of the main ways to realize the speed regulation of medium and high voltage motor is to study the three-level inverter circuit. This paper mainly focuses on the diode clamped three-level inverter circuit. The topology of its main circuit is analyzed and its working principle is studied. Based on this, the mathematical model of three-level inverter is established. The sinusoidal pulse width modulation (SPWM) and space vector modulation (SVPWM) of diode clamped three-level inverter are analyzed in detail. The basic principles. The realization method. The SPWM modulation mode adopts carrier phase, carrier inverse phase, carrier longitudinal displacement, injection of zero sequence component, injection of third harmonic to carry on the comparative analysis. At the same time, the Fourier transform is used to analyze the output characteristics. In this paper, six small sectors and four small sectors are used for SVPWM modulation, and the output characteristics are compared and analyzed. Based on the topology of diode clamped three-level inverter circuit, the cause of neutral point potential imbalance is analyzed. The midpoint potential modulation algorithm is proposed. Finally, the simulation models of various modulation modes are established by Matlab/simulink, and the output results of various modes are analyzed by FFT. The validity of various modulation methods is verified. The output characteristics such as DC voltage utilization ratio and output harmonic content are compared and analyzed. Finally, the vector control mode commonly used in domestic locomotive traction drive system is taken as an example. This paper mainly studies the principle and realization process of motor speed regulation system based on SVPWM mode of field-oriented control. The simulation model of traction inverter is built by using Matlab/Simulink. The fast response characteristics of the system, the traction characteristics of the motor and the effectiveness of the control strategy described in this paper are verified by the simulation research on the motor starting and braking.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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