考虑谐波特性和中点电位平衡的Vienna整流器改进断续脉宽调制策略  

Modified DPWM strategy for Vienna rectifier considering current harmonic distortions reduction and neutral point voltage balance

作　　者：黄海宏[1] 王超[1] 王海欣[1] HUANG Hai-hong;WANG Chao;WANG Hai-xin(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：《电机与控制学报》2020年第4期23-31,共9页Electric Machines and Control

基　　金：国家自然科学基金(51177037)。

摘　　要：Vienna整流器在以高功率密度为设计目标的场合中,应用十分广泛。且Vienna整流器通常运行在较高的开关频率下,因此减小开关损耗,降低装置的发热,十分有必要。断续脉宽调制(DPWM)可以降低开关损耗,本文研究了一种适用于Vienna整流器的具有最大开关损耗降低效果的DPWM方法。为改善DPWM相对于SPWM和SVPWM方法谐波特性较差的缺点,提出了一种适用于Vienna整流器的改善谐波特性的改进DPWM方法。该方法通过对子扇区注入的零序分量进行修正,改善了三相电流的谐波特性。为针对三电平拓扑固有的中点电位不平衡问题,提出了DPWM方法的中点电位平衡控制策略。最后,通过仿真和实验验证了本文提出的调制方法和中点电位平衡控制策略的有效性,对不同调制方法Vienna整流器的工作效率和电流THD进行了比较。Vienna rectifier has been widely applied when power density is the design objective.Vienna rectifier usually works with high switch frequency,so it is necessary to reduce the switch losses to control the temperature of the device.Discontinuous pulse width modulation(DPWM)can reduce the switch losses of the power device.A DPWM method with minimum switch losses is discussed for Vienna rectifier in this paper.To reduce the current harmonic distortions of DPWM method,a modified DPWM method was introduced.This method improved the harmonic characteristics of the three-phase current by modifying the zero sequence component injected into the sub sector.The three-level topology has the problem of neutral point potential unbalanced.Hence,a neutral point potential balance control strategy for DPWM method was introduced.Finally,all these proposed modulation and control strategies were verified by the simulation and experiment results,and Vienna rectifier’s efficiency and current THD with different modulation methods were compared.

关 键 词：VIENNA整流器 断续脉宽调制 开关损耗降低 中点电位平衡 电流谐波 空间矢量 

分 类 号：TM46[电气工程—电器]