三相逆变器在不平衡负载下的2种调制策略对比  

Comparison between two modulation strategies of three-phase inverter with unbalanced load

作　　者：刘德红[1] 汪光森[1] 胡安[1] 郭俊华[1] 

机构地区：[1]海军工程大学舰船综合电力技术国防科技重点实验室电力电子技术研究所,湖北武汉430033

出　　处：《电力自动化设备》2009年第1期41-45,共5页Electric Power Automation Equipment

基　　金：国家自然科学基金委员会创新群体科学基金资助项目(50721063);国家自然科学基金资助项目(50737004;50607020)~~

摘　　要：在不平衡负载条件下,对比分析了2种调制策略对三相逆变器静、动态特性的影响:采用正、负序同步旋转坐标系下的电压正、负序值调制策略;采用延迟信号撤销法(DSC)分离出正、负序同步坐标系下的电压正、负序分量值调制策略。前者存在PI调节器无法完全消除电压正弦参考信号与电压反馈信号的静差问题;后者存在DSP处理DSC分离电压正、负序分量时有1/4电网基波周期的延时取整处理问题。基于Matlab/Simulink对2种策略进行仿真并在380 kW的三相逆变器样机上做了实验,结果证实:无论是在空载还是稳态时,采用正、负序分量值控制策略具有更好的稳压精度和较小的总谐波畸变率;处理DSC延迟问题时做的取整简化处理对系统静、动态特性影响不大。Static and dynamic characteristics of three-phase inverter under unbalanced load are compared between two modulation strategies： the positive and negative sequence values in synchronous rotating frame and the positive and negative sequence components separated by DSC（Delayed Signal Cancellation）. The PI controller of the former can＇t completely remove the static error between voltage feedback and sinusoidal reference, while there is setting error of one-quarter cycle delay in the later. The two modulation strategies are simulated with Matlab/Simulink and validated on a 380 kW three-phase inverter prototype. Results show that, the latter has better precision and smaller THD under both no-load and stable conditions, and the rounding operation of DSP in one-quarter cycle delay setting has little effect on system static and dynamic characteristics.

关 键 词：三相逆变器 正序分量值 不平衡负载 

分 类 号：TM464[电气工程—电器]