一种N相中点钳位型三电平逆变器的PWM策略  

A PWM Strategy for Neutral Point Clamped N-Phase 3-Level Inverter

作　　者：姜卫东[1] 李劲松 王金平[1] 李来保 翟飞 Jiang Weidong;Li Jinsong;Wang JinPing;Li Laibao;Zhai Fei(School of Electrical Engineering and Automation Hefei University of Technology Hefei 230009 China)

机构地区：[1]合肥工业大学电气与自动化工程学院,合肥230009

出　　处：《电工技术学报》2019年第10期2194-2206,共13页Transactions of China Electrotechnical Society

摘　　要：本文研究了N相中点钳位型三电平逆变器(NPC 3LI)的调制策略和中点电压控制方法。提出一种适用于N相NPC 3LI的PWM策略——N相虚拟空间矢量脉宽调制策略(N-VSVPWM),这种PWM策略通过准确地计算和执行每相1电平占空比实现中点电压无条件平衡。一些非理想因素(如死区插入)会破坏该PWM策略的中点电压自平衡能力,因此,本文还提出基于N-VSVPWM的中点电压主动控制方法。理论分析和实验结果表明,N-VSVPWM较空间矢量脉宽调制策略(SVPWM)具有更好的中点电压控制能力,较好的谐波特性,但是开关损耗有所上升。This paper studies the modulation strategy and neutral point voltage control method of N-phase neutral point clamped 3-level inverter. A novel PWM strategy for N-phase NPC 3LI is proposed, named N-phase virtual space vector pulse width modulation strategy. This PWM strategy unconditionally balances the midpoint voltage by accurately calculating and executing a 1-level duty cycle per phase. Some non-ideal factors, such as dead zone insertion, will destroy the midpoint voltage self-balancing capability of the PWM strategy. Therefore, this paper also proposes active neutral point voltage control based on N-VSVPWM. Theoretical analysis and experimental results show that N-VSVPWM has better midpoint voltage control capability and better harmonic characteristics than space vector pulse width modulation strategy, but the switching loss increases.

关 键 词：三电平逆变器 N相 中点钳位 载波 中点电压 

分 类 号：TM464[电气工程—电器]