基于动态调整小矢量选择方式的三电平变换器中点电压平衡控制  

Neutral point voltage balancing control of three-level converter based on dynamic adjustment of small vectors selection mode

作　　者：赵红雁[1] 刘明[2] 李艳[1] 林飞[1] 张纯江[2] ZHAO Hongyan;LIU Ming;LI Yan;LIN Fei;ZHANG Chunjiang(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China;School of Electrical Engineering,Yanshan University,Qinhuangdao,Hebei 066004,China)

机构地区：[1]北京交通大学电气工程学院,北京100044 [2]燕山大学电气工程学院,河北秦皇岛066004

出　　处：《燕山大学学报》2022年第1期73-81,共9页Journal of Yanshan University

基　　金：国家自然科学基金资助项目(51877007)。

摘　　要：直流侧中点电压不平衡是三电平变换器中的常见问题之一,中点电压不平衡将导致直流侧两个串联均压电容和桥臂功率开关的电压应力不均衡,甚至会造成二者过压损坏;同时也会使得交流电流中谐波成分增加、总谐波畸变率增大。传统中点电压平衡控制方法的控制策略复杂,动态响应速度慢,影响了三电平变换器在对直流侧中点电压平衡度要求高的场合的应用,本文以三相VIENNA电路为例,对该问题展开研究,通过分析VIENNA电路中小矢量对中点电压波动的作用与影响,提出了一种基于动态调整小矢量选择方式的控制策略。通过判断中点电压的波动情况动态选择不同的小矢量对电路进行作用,完成对中点电压的实时调整和控制。最后,利用仿真和硬件平台,把所提出的方法与传统的零序电压注入法做了比较分析和验证,验证了该方法的可行性和具有的优势。The unbalanced neutral point voltage in DC side is one of the common problems in three-level converter.The unbalanced neutral point voltage will lead to the unbalanced voltage stress of the two series voltage-sharing capacitors and the bridge-arm power switches in DC side,and even lead to overvoltage damage;at the same time,the harmonic component and total harmonic distortion rate of AC current increase.The control strategy of traditional neutral point voltage balancing control method is complex and the dynamic response is slow,which affects the application of three-level converter in the situation of requiring high neutral point voltage balancing coefficient.To study the problem,three-phase VIENNA circuit is taken as an example and a control strategy based on dynamic adjustment of small vector selection mode is proposed.By judging the fluctuation of the neutral point voltage,different small vectors are selected to act on the circuit dynamically to complete the real-time adjustment and control of the neutral point voltage.Finally,the simulation and hardware platform are used to compare the proposed method with the traditional zero sequence voltage injection method,and the feasibility and advantages of the proposed method are verified.

关 键 词：中点电压 平衡控制 三电平变换器 VIENNA电路 小矢量 

分 类 号：TM401[电气工程—电器]