基于调制波分解的中点钳位型三电平逆变器的混合调制策略  

Hybrid modulation strategy for neutral point clamped three-level inverter based on modulation wave decomposition

作　　者：王金平[1] 吉耀聪 张庆岩 刘圣宇 姜卫东[1] WANG Jinping;JI Yaocong;ZHANG Qingyan;LIU Shengyu;JIANG Weidong(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,安徽合肥230009

出　　处：《电机与控制学报》2023年第11期66-78,共13页Electric Machines and Control

基　　金：国家自然科学基金(52077050)。

摘　　要：对于中点钳位型三电平逆变器,传统的载波脉宽调制在高调制度低功率因数下中点电压会发生三倍频波动,而虚拟空间矢量调制虽然能实现中点电压无条件平衡,却存在开关损耗高的问题。针对上述问题,基于调制波分解的多约束目标的协调,提出一种适用于中点钳位型三电平逆变器的混合调制策略。该调制策略采用双调制波单载波比较的方式实现,分析开关次数和中点电压无条件平衡的两类约束,为了在确保中点电压平衡的条件下降低开关损耗,提出上述两类约束的混合调制策略。在此基础上,探讨两种约束下的中点电压主动控制方法。另外,还对比了混合调制策略与其他调制策略的性能指标。混合调制策略可以在全调制度全功率因数下实现中点电压平衡,且相比虚拟空间矢量调制开关损耗有所降低,实验结果证明了其可行性和优越性。For neutral point clamped three-level inverter(NPC TLI),traditional carrier-based pulse width modulation(CBPWM)can cause triple frequency fluctuations in neutral point voltage(NPV)un-der high modulation index and low power factor.Although virtual space vector pulse width modulation(VSVPWM)can achieve unconditional balance of NPV,it has the problem of high switching loss.To address the above issues,a hybrid modulation strategy suitable for NPC TLI was proposed based on the coordination of multi-constraint objectives through modulation wave decomposition.It is realized by com-paring double modulation waves with a single carrier.Two types of constraints for switching times and un-conditional balanced neutral point voltage were analyzed.In order to reduce the switching loss under the condition of ensuring NPV balance,the proposed hybrid modulation strategy with the above two con-straints was obtained.On this basis,active NPV control methods under these two constraints were dis-cussed.In addition,the performance indicators of the proposed strategy and other strategies were com-pared.The hybrid modulation strategy can achieve NPV balance under full modulation index and full power factor,and has reduced switching losses compared to VSVPWM.Experimental results verify the feasibility and superiority of the proposed strategy.

关 键 词：中点钳位型三电平逆变器 调制波分解 中点电压主动控制 开关损耗 调制策略 

分 类 号：TM464[电气工程—电器]