三电平变流器直流侧电容的纹波分析  

Ripple Components Analysis of DC Capacitor of Three-level Converters

作　　者：李星宇[1] 李崇坚[1] 朱春毅[1] 邢卫宏[1] 王成胜[1] 

机构地区：[1]冶金自动化研究设计院,北京100071

出　　处：《电气传动》2013年第S1期93-97,共5页Electric Drive

基　　金：国家高技术研究发展(863);计划资助项目(2011AA050403)

摘　　要：三电平中点箝位(NPC)变流器具有优良的性能,在高压大功率的场合得到越来越广泛的应用。其中直流侧电容需承受的纹波电流影响电容的大小和寿命,直流侧纹波电压的大小影响功率器件需承受的电压,因此直流侧的纹波成分对变流器的设计至关重要。通过对变流器拓扑和开关调制方式的分析,得出了三电平NPC变流器直流侧电容电流和电压纹波的解析表达式,其中纹波电流的有效值随调制度和负载功率因数变化,纹波电压随直流电容值和负载功率因数变化。最后通过一些工作点的仿真,验证了解析表达式的有效性。Three-level Neutral Point Clamped(NPC)converters have been widely applied in high voltage and high power applications for their excellent performances. The capacitor size and life are affected by the current stress on the capacitor; the voltage to be blocked by the power devices is affected by the voltage ripple in the converter DC link capacitors. Hence,these ripple components are very important for the design of the converter. The analytical expressions for the current and voltage ripple in the capacitors of a three level NPC converter through analytical study of the topology and modulation are derived. The DC link capacitor current root mean square value varies with modulation index and load power factor; the DC link capacitor voltage ripple varies with the DC link capacitors value and load power factor. The analytical expressions derived are validated through simulations results at a number of operating points.

关 键 词：直流电容 纹波分析 三电平 中点箝位变流器 

分 类 号：TM46[电气工程—电器]