A Space Vector PWM Scheme for Multilevel lnverters Based on Two-Level Space Vector PWM

1. INTRODUCTION MULTILEVEL inverters are increasingly being used in high-power medium voltage applications due to their superior performance compared to two-level inverters, such as lower common-mode voltage, lower dv/dt, lower harmonics in output voltage and current, and reduced voltage on the power switches.     

Analysis of Output Current Ripple rms in Multiphase Drives Using Space Vector Approach

Multiphase variable-speed drives, supplied from two-level voltage source inverters (VSIs), are nowadays considered for various industrial applications. Although numerous pulsewidth modulation (PWM) schemes for multiphase VSIs, aimed at sinusoidal output voltage generation, have been developed, no detailed analysis of the impact of these modulation schemes on the output current ripple has ever been reported. This paper presents a comprehensive analytical analysis and comparison of the output current ripple caused by the application of three different continuous PWM schemes, using a five-phase VSI as an example. Main properties of sinusoidal PWM, fifth harmonic injection PWM, and space vector PWM are elaborated and analyzed using the harmonic flux concept. Space vector theory is applied in the analysis. As a result, harmonic distortion factors are obtained for each PWM scheme. Theoretical considerations are verified by simulations and experimental investigation using a custom-designed five-phase VSI-fed induction motor drive.      

Space Vector Modulation for Two-Level Unidirectional PWM Rectifiers

This paper presents the concepts for application of space vector modulation to two-level unidirectional pulsewidth modulation (PWM) rectifiers, and a methodology for the use of this modulation is proposed and applied in three different groups of rectifiers. For each group of rectifiers, the converter switching stages are analyzed to determine switch control signals for space vector modulation. One switching sequence is proposed for all rectifiers in order to minimize the number of switch commutations and reduce the switching losses. Duty cycle functions are determined, and the desired switching sequences are performed by a simple PWM, without the need to determine the present sector of the vector. For this purpose, it is necessary to impose the desired current sectors from input voltage references only. In order to validate the proposed modulation techniques, simulation and experimental results are presented for a 20-kW prototype.      

Multilevel Multiphase Space Vector PWM Algorithm

In the last few years, interest in multiphase converter technology has increased due to the benefits of using more than three phases in drive applications. Besides, multilevel converter technology permits the achievement of high power ratings with voltage limited devices. Multilevel multiphase technology combines the benefits of both technologies, but new modulation techniques must be developed in order to take advantage of multilevel multiphase converters. In this paper, a novel space vector pulsewidth modulation (SVPWM) algorithm for multilevel multiphase voltage source converters is presented. This algorithm is the result of the two main contributions of this paper: the demonstration that a multilevel multiphase modulator can be realized from a two-level multiphase modulator, and the development of a new two-level multiphase SVPWM algorithm. The multiphase SVPWM algorithm presented in this paper can be applied to most multilevel topologies; it has low computational complexity and it is suitable for hardware implementations. Finally, the algorithm was implemented in a low-cost field-programmable gate array and it was tested in a laboratory with a real prototype using a five-level five-phase inverter.     

三相PWM整流器滞环空间矢量控制的研究

本文介绍了三相PWM整流器的一种基于不定频滞环的空间矢量脉宽调制（sVPWM）电流控制方法。该方法结合了滞环电流控制和SVPWM电流控制的优点,在取得快速电流响应的同时又能有效地降低开关频率,提高系统的运行效率。用Simulink模块库建立仿真模型,仿真结果表明了该控制策略的可行性。     

基于电压空间矢量的三相PWM整流器控制研究

首先建立了三相电压型PWM整流器的数学模型，并对其矢量控制策略进行了分析，在此基础上提出了一种简单的电压空间矢量算法，该算法根据参考电压矢量在坐标系上的分量直接计算电压空间矢量在各个扇区内的作用时间，实验结果验证了所提出控制算法的可行性。     

基于空间电压矢量的三相电压型PWM整流器的研究

建立了三相电压型PWM整流器在三相静止坐标系和两相同步旋转坐标系下的数学模型,将双闭环工程设计方法应用于PWM整流器,研究了其前馈解耦控制策略。在此基础上结合空间矢量调制（SVPWM）的算法,设计了三相电压型PWM整流器控制系统,并在Matlab的Simulink中进行了系统仿真。仿真结果表明,设计方法可行,具有良好的动静态性能,实现了单位功率因数。     

电压空间矢量PWM控制技术的探讨

本文利用SVPWM控制技术产生的正六边形旋转磁场,在基本电压矢量之间插入零电压矢量。利用得到的SVPWM波及傅立叶级数基本知识,证明了基频以下调速时,逆变器输出电压一频率比为恒值这一结论。这对准确而全面理解SVPWM控制技术、深刻掌握交流调速系统有关内容具有重要意义。     

SVPWM技术的研究及其仿真实现

SVPWM技术比普通的SPWM调制谐波分量小,容易数字化实现,在交流传动领域得到了广泛的应用,并逐渐应用到大容量高电压领域。本文详细地分析了SVPWM控制技术的工作原理,采用MATLAB／Simulink对控制算法进行仿真。仿真结果表明空间矢量脉宽调制方案正确可行。     

Current Reconstruction Techniques for Survivable Three-Phase PWM Converters

In high-performance three-phase pulsewidth-modulated (PWM) converter systems used in generator and motor drives, failure of current sensors will directly interrupt the system performance, and will even cause disastrous consequences. Redundancy in design is one of the popular choices to overcome this issue. However, this usually leads to an undesirable increase in size and cost. This letter presents two novel model-independent current reconstruction methods for three-phase PWM converter systems based on space vector modulation. Using the proposed sensor placement and software algorithm, phase currents within a three-phase converter can be reconstructed to an acceptable level of accuracy under single-survived-sensor ($S^3$) scenario. A hardware prototype is built and fault tolerant algorithm is implemented using a DSP (TMS320F2812). Experiments are conducted under worst-case scenario to verify the flexibility of sensor placement/converter layout and software algorithm.      

基于SVPWM的异步电动机控制系统的仿真研究

本文在深入分析电压空间矢量脉宽调制（SVPWM）基本原理及算法的基础上,应用MATLAB／SIMULINK构建了与原理及算法相对应的电动机控制系统的仿真模型并给出了SVP哪触发单元的详细仿真结构。为了便于比较仿真波形,本文也给出了SPWM逆变器供电的同一异步电动机控制系统的仿真波形。     

基于SVM-PWM的异步电动机直接转矩控制

文中介绍了空间矢量脉宽调制(SVM-PWM)的基本原理,构建了异步电动机直接转矩控制的模型,定子电压由空间矢量脉宽调制方式实现。通过MATLAB/Simulink对该系统进行了仿真,结果表明空间矢量脉宽调制直接转矩控制能够有效地减少电动机转矩和磁链的脉动。     

Space Vector Modulation for Low Switching Frequency Current Source Converters With Reduced Low-Order Noncharacteristic Harmonics

High-power current source converters (CSCs) are usually implemented with gate turn off thyristors (GTOs) or integrated gate commutated thyristors (IGCTs) that present a maximum switching frequency of a few kilohertz. Space vector modulation (SVM) offers a very elegant way of generating CSC gating signals online with increased gain and reduced switching frequency. However, for very low switching frequency, SVM results in low-order (5th and 7th) noncharacteristic harmonics complicating the design of the input filter. The reduction of the magnitude of these harmonics has been sought mostly through new sequences of space vectors (states) that present better performance for different ranges of modulation index and power factor. Moderate improvement can be obtained by calculating the statespsila on times for the reference vector in the middle of an SVM cycle. This paper proposes calculating the statespsila on times as the reference vector rotates. Simulation results show that this approach results in a significant reduction in the harmonic distortion of these two components, which, for a selected sequence of states, can be limited to 0.3% of the fundamental component as the modulation index varies from 0.05 to 1.0. Experimental results obtained with a digital signal processor development kit are also provided to show the superior performance of the proposed techniques.     

逆变器的空间电压矢量控制及DSP设计

介绍了空间电压矢量脉宽调制(SVPWM)的基本原理,提出了矢量时间计算的简单算法,采用了快速扇区判断方法,在Matlab/Simulink环境下对SVPWM控制的逆变器系统进行了仿真,并给出了相应的仿真结果,同时基于TI公司DSPLF2407芯片进行了控制算法的设计,给出了算法流程。     

基于TMS320F240的空间电压矢量PWM的实现

文中叙述了空间电压矢量（SVPWM）的基本原理，介绍了采用矩阵求妥两相邻向量作用时间的方法和用数字信号处理器TMS320F240生成对称空间电压矢量的方法，它的优异性能可以实时完成SVPWM的控制算法，且速度快，精度高。     

n电平空间矢量算法的优化及其硬件实现

 本文提出了一种适合硬件实现的多电平空间矢量调制算法,该算法利用空间矢量图的几何对称性来实现算法优化.多电平空间矢量图可以划分为几何形状完全一致的六大扇区,优化算法通过扇区之间的对应关系把矢量调制算法的计算集中在一个扇区内完成.与传统的空间矢量算法相比,计算量减少为原来的1/6,更适合用硬件实现.为了设计出的硬件电路具有通用性,本文给出了具体设计过程.最后,文章以两电平和三电平IP(Intellectual Property)核的设计为实例验证了优化算法的正确性和有效性.     

电压空间矢量PWM控制的仿真研究

本文介绍了电压空间矢量调制的原理,并对电压矢量的合成做了详细分析,给出SVPWM调制方式与载波调制的关系及用载波调制的方法实现电压矢量控制的具体步骤。最后通过Matlab/simulink进行仿真验证。     

三相PWM整流器电压空间矢量控制的实现

提出了一种便于数字实现的三相PWM整流器电压空间矢量的控制算法，该算法采用输入电压空间矢量定向，根据参考电压矢量直接计算空间电压矢量的位置和作用时间；利用DSP（数字处理器）实现了三相PWM整流器全数字化控制，并得出了最终实验结果。     

基于空间矢量调制三相电压型PWM整流系统的仿真

正弦脉冲宽度调制(SPWM)技术应用于传统的电压型PWM整流中,SPWM的控制波形可由相间解耦得到。然而,这个过程复杂且直流电压利用率很低。本文提出了一种在同步参考坐标下的三相电压模型的控制策略,空间矢量脉冲宽度调制(SVPWM)。整流器具有高质量的直流侧电压和功率因数。文章提供了MATLAB/SIMULINK的仿真模型。结果证实了模型的正确性及其控制方法。仿真结果表明,与传统的SPWM方法相比,这种方法能明显提高系统的动态性能。