基于空间矢量PWM的多电平NPC功率变流器电压平衡控制  

Voltage Balance Control of Multi-Stage NPC Power Converter Based on Space Vector PWM

作　　者：陈豪 王法 倪瑞君 王佳伟 彭静 王军 薛士敏[3] CHEN Hao;WANG Fa;NI Ruijun;WANG Jiawei;PENG Jing;WANG Jun;XUE Shimin(Jiaxing Hengchuang Electric Power Design and Research Institute Co.,Ltd.,Jiaxing 314033,Zhejiang,China;State Grid Linyi Power Supply Company,Linyi 276000,Shandong,China;School of Electrical Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]嘉兴恒创电力设计研究院有限公司,浙江嘉兴314033 [2]国网临沂供电公司,山东临沂276000 [3]天津大学电气工程学院,天津300072

出　　处：《电网与清洁能源》2022年第8期30-39,共10页Power System and Clean Energy

基　　金：国家自然科学基金资助项目(51977144)。

摘　　要：传统NPC拓扑受到直流中性点上电压不平衡的影响,不仅导致系统不稳定,还会影响电容器和半导体器件的额定值,增加总功率损耗。基于此,提出了一种适用于单相三线配电系统的新型变流器拓扑结构及其控制策略。所提变流器为中性点箝位(NPC)的H桥。为了解决基于NPC的变换器直流端口电容电压平衡问题,还提出了一种基于空间矢量PWM的直流端口电压平衡方法来平衡中性点电压,该方法充分考虑了输出电压的谐波影响和开关损耗,还定义了所应用的矢量序列。最后,通过与传统变流器进行仿真比较,以验证变流器在平衡和不平衡负载情况下的开关损耗的优越性。此外,还进行了实验验证,结果验证了所提电压平衡方法的有效性和优越性。The traditional NPC topology is affected by the voltage imbalance at the DC neutral point,which not only leads to the system instability,but also affects the ratings of capacitors and semiconductor devices,and increases the total power loss.Based on this,this paper proposes a novel converter topology and its control strategy,which are suitable for the AC-DC converter link of the microgrid with DC distributed power supply or the AC-DC microgrid. The proposed converter is a neutral point clamped(NPC)H-bridge. In order to solve the problem of capacitive voltage balance of the DC port of the NPC-based converter,a DC port voltage balance method based on space vector PWM is proposed to balance the neutral voltage. This method fully considers the harmonic effect of output voltage and switching loss, and defines the applied vector sequence.Finally,the simulation comparison with the traditional converter is carried out to verify the advantages of switching loss of the converter under balanced and unbalanced loads. In addition,experiments are carried out to verify the effectiveness and superiority of the proposed voltage balancing method.

关 键 词：三角形负载 中点箝位(NPC)逆变器 电容电压平衡 空间矢量调制 混合拓扑 

分 类 号：TM28[一般工业技术—材料科学与工程]