考虑输出电压平衡的三相四开关逆变器SVPWM过调制策略  

Overmodulation SVPWM algorithm of three-phase four-switch inverter for balanced output voltages

作　　者：李泽 郭源博[1] 张铭 张晓华[1,2] LI Ze;GUO Yuan-bo;ZHANG Ming;ZHANG Xiao-hua(School of Electrical Engineering,Dalian University of Technology,Dalian 116024,China;School of Electrical Engineering and Automation,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]大连理工大学电气工程学院,辽宁大连116024 [2]哈尔滨工业大学电气工程及自动化学院,哈尔滨150001

出　　处：《电机与控制学报》2019年第7期53-62,共10页Electric Machines and Control

基　　金：国家自然科学基金(51407023,51377013);中央高校基本科研项目(DUT15RC(4)04)

摘　　要：针对三相四开关逆变器(TPFSI)电压输出能力受限,且传统过调制方法存在输出三相电压基波幅值不平衡的问题,提出一种考虑输出电压平衡的空间矢量脉宽调制过调制算法。首先,推导三相四开关逆变器输出平衡三相电压的约束条件;然后,根据调制比的大小,将过调制区域分为三部分,即过调制Ⅰ区、过调制Ⅱ区和过调制Ⅲ区,并基于叠加定理分别选择用于矢量合成的电压矢量和加权系数,合成期望的电压矢量;最后,对传统的过调制算法与提出的基于叠加定理的过调制算法进行仿真研究和实验验证。结果表明:与传统的三相四开关逆变器过调制算法相比,所提出的过调制算法能够输出平衡的三相电压,且基波幅值与调制比呈线性关系,同时避免了控制角和保持角的在线计算或离线存储,具有易于数字化实现的优点。The ability of voltage output for three-phase four-switch inverter(TPFSI)is limited,and the problem of three-phase fundamental voltage unbalance exists in traditional overmodulation strategy.As a result,an overmodulation algorithm of TPFSI for balanced output voltages was proposed.Firstly,the constraint condition for TPFSI outputting balanced three-phase voltages was derived.Then,according to the value of the modulation index,the overmodulation region is divided into three parts,namely overmodulation region I,overmodulation region II,and overmodulation region III.Next,the voltage vectors and the corresponding weighting coefficients were chosen to synthesis the reference voltage vector.Finally,the output voltage performance of the TPFSI using traditional overmodulation algorithm and the proposed overmodulation algorithm was simulated and validated,respectively.The results show that compared with traditional overmodulation algorithm,the proposed overmodulation algorithm based on superposition principle can output the balanced three-phase voltages,and the fundamental component of the output voltage is proportional to the modulation index.Meanwhile,the proposed algorithm can be easily digitally realized without online calculation or offline storage for the control angles and holding angles.

关 键 词：三相四开关逆变器 三相输出电压平衡 叠加定理 空间矢量脉宽调制 过调制 

分 类 号：TM46[电气工程—电器]