NPC三电平逆变器改进型虚拟空间矢量调制  

Improved virtual space vector modulation for NPC three-level inverter

作　　者：贾万水 张成[1,2] 熊梓辰 Jia Wanshui;Zhang Cheng;Xiong Zichen(College of Electrical and Information Engineering,Hunan University of Technology,Hunan Zhuzhou 412007,China;China Railway Signal and Communication(Changsh a)Railway Traffic Control Technology Co.,Ltd,Hunan Changsha 410000,China)

机构地区：[1]湖南工业大学电气与信息工程学院,湖南株洲412007 [2]通号(长沙)轨道交通控制技术有限公司,长沙410000

出　　处：《船电技术》2022年第4期18-23,共6页Marine Electric & Electronic Engineering

摘　　要：NPC三电平逆变器在工业环境中的应用越来越广泛,但此类逆变器存在直流母线中点电压偏移以及共模电压问题。提出一种改进型虚拟空间矢量调制策略,该调制选取共模电压较小的基本电压矢量合成虚拟矢量,改进后的调制产生的共模电压仅为传统调制的50%,并且这些虚拟矢量产生的电流均为零,直流母线中点电压得以控制。同时,改进型调制采用g-h坐标系,计算量极大简化。所提调制策略通过减少开关序列的切换次数使功率器件开关次数大幅降低从而提升中点电压平衡速度62.5%。最后,使用MATLAB/Simulink仿真平台以及RT-LAB半实物平台对改进型调制策略的正确性、可行性进行了验证。NPC three-level inverter has found an increasingly wide utilization in industrial fields. However,this type of inverter has problems with neutral-point voltage fluctuation and common mode voltage. An improved virtual space vector modulation strategy is proposed, which selects the voltage vector with lower common mode voltage to synthesize virtual vector, so that the common mode voltage generated by the improved modulation is only 50% of the traditional modulation. The neutral-point current produced by these virtual vectors is zero, so the neutral-point voltage can be controlled. At the same time, the g-h coordinate system is adopted, which greatly simplifies the calculation. The switching times of the switching sequence are decreased in the proposed modulation strategy, and the number of the power device switches are significantly reduced, therefore, the neutral-point voltage balance speed is increased by 62.5%. Finally,simulation and experiment verify the correctness and feasibility of the new modulation strategy.

关 键 词：NPC三电平逆变器 中点电压平衡 共模电压 虚拟空间矢量 

分 类 号：TM612[电气工程—电力系统及自动化]