Z源逆变器直通电流回路及功率开关管电流应力分析  

Analysis of Circuit Path and Current Stress of Power Devices under Shoot-Through Mode in Z-Source Inverter

作　　者：张千帆[1] 董帅[1] 周超伟 程树康[1] 

机构地区：[1]哈尔滨工业大学电气工程及自动化学院,哈尔滨150001

出　　处：《电工技术学报》2016年第4期123-128,共6页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51177027)

摘　　要：Z源逆变器直通方式按桥臂直通数目可以分为单相、两相和三相直通,其中三相直通方式较其他两种具有开关管电流应力更小的特点。现有文献分析三相直通方式下功率开关管的最大电流应力是在直通电流比较大的基础上得出的,其值要大于负载相电流峰值。本文揭示了小电压增益和低功率因数下,功率开关管的最大电流应力与负载相电流峰值相等。并详细分析了三相直通方式时不同直通电流下负载的电流回路,为进一步分析开关管损耗、温升和热管理奠定基础;揭示了当Z源逆变器工作于直通状态,直通电流不同时负载的电流回路也不尽相同。针对不同的电流情况,得出了相应的开关管电流应力表达式,为三相直通方式下选择开关管的功率等级提供了依据。实验验证了理论分析的正确性。The three shoot-through modes in Z-source inverter are one-phase, two-phase and three-phase shoot-through. The current stress of the power device is lowest in the third mode. Generally, in three-phase shoot-through mode, the current stress of power devices is analyzed based on big shoot through current, and its value is greater than the peak value of load current. This paper reveals the current stress of power devices is equal to the peak value of load current with small voltage gain and low power factor. Current path of the load in three-phase shoot-through mode is analyzed, which supports further analysis on loss, temperature increment and thermal management of the power devices. It is shown that freewheeling current path in shoot-through state is different if the value of shoot-through current is different. The expression of power device current stress is obtained under different freewheeling conditions, which provides the theoretical basis for the selection of the current level of power devices. Experimental results verify the theoretical analysis.

关 键 词：Z源逆变器 直通方式 电流回路 电流应力 

分 类 号：TM46[电气工程—电器]