有源箝位型三电平变频器功率器件损耗分析

针对传统中点箝位型三电平变频器运行过程中存在功率器件损耗分布不均匀问题,介绍了有源箝位型三电平拓扑的工作原理和基本调制策略,分析了有源箝位型三电平变频器的损耗特性。有源箝位型三电平拓扑使用双向功率器件取代传统中点箝位型三电平中的箝位二极管,通过选择恰当的零电压状态组合,可实现功率器件损耗均衡的目的。仿真结果表明,在各种典型工作状态下,相比于中点箝位型三电平拓扑,有源箝位型拓扑可更好地平衡功率器件内外管损耗,提升了变频器容量。

Analysis of loss distribution for power devices of active neutral point clamped three-level inverter

In view of problem of uneven loss distribution of power devices in running process of traditional neutral point clamped three level inverter,this paper introduced working principle and basic modulation strategy of active neutral point clamped three-level topology,analyzed loss characteristics of active neutral point clamped three-level converter.Active neutral point clamped three-level topology uses bidirectional power device to instead of traditional clamp diode of neutral point clamped three level,which can realize purpose of loss equilibrium of power device by selecting appropriate combination of zero voltage condition.The simulation results show that active neutral point clamped three-level topology can balance the loss of power devices,and improve the converter capacity under various typical working conditions compared with the traditional neutral point clamped three level.