三电平NPC逆变器中点电压平衡混合调制策略  

THREE-LEVEL NPC INVERTER MIDPOINT VOLTAG BALANCE HYBRID MODULATION STRATEGY

作　　者：李玥 黄孙伟 徐川[1,2] Li Yue;Huang Sunwei;Xu Chuan(School of Electrical Engineering,Tianjin University of Technology,Tianjin 300384,China;Tianjin Key Laboratory for Control Theory and Application in Complicated,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]天津理工大学电气电子工程学院,天津300384 [2]天津理工大学天津市复杂控制理论与应用重点实验室,天津300384

出　　处：《计算机应用与软件》2021年第2期85-92,共8页Computer Applications and Software

摘　　要：针对二极管中点钳位型(neutral point clamped,NPC)三电平逆变器直流侧电容电压不平衡问题,提出一种混合空间矢量脉宽调制技术(Space vector pulse width modulation,SVPWM)和虚拟空间矢量脉宽调制技术(Virtual space vector pulse width modulation,VSVPWM)的控制策略。采用60°坐标系,通过大扇区旋转模型和小扇区重新划分以简化计算,即在低调制比时,通过一系列处理简化SVPWM算法,并设计PI控制器以调节小矢量作用时间平衡中点电压;在高调制比时,改进VSVPWM,重新定义小、中矢量在降低共模电压的同时设计滞环比较器以平衡中点电压。仿真和实验验证了该方法的正确性和有效性。In order to solve the problem of DC-capacitor voltage imbalance of diode neutral point clamped(NPC)three-level inverter,a control strategy of hybrid space vector pulse width modulation(SVPWM)and virtual space vector pulse width modulation(VSVPWM)is proposed.In 60°coordinate system,large sector rotation model and small sector re-division were used to simplify the calculation.When the modulation ratio was low,a series of processing was used to simplify the SVPWM algorithm,and a PI controller was designed to adjust the small vector action time and balance the neutral point voltage.When the modulation ratio was high,the VSVPWM was improved to redefine the small and medium vectors,and the hysteresis comparator was designed to balance the neutral point voltage while reducing the common mode voltage.The simulation and experimental results show that the proposed method is correct and effective.

关 键 词：电容电压不平衡 调制比 简化空间矢量脉宽调制技术 PI控制器 改进虚拟空间矢量脉宽调制技术 滞环比较器 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术] TM843[电气工程—高电压与绝缘技术]