大功率三电平变频器损耗及IGBT结温分析

Analysis of High-power Three-level Inverter Losses and IGBT Junction Temperature

提出一种大功率三电平变频器损耗及器件结温计算的简便方法,通过实验数据建立绝缘栅双极型晶体管(IGBT)模块导通损耗和开关损耗数学模型,并利用功率器件驱动信号来计算变频器的损耗,综合考虑了调制策略、负载功率因数、输出电流谐波、直流母线电压波动等因素,适用于变频器任何工况下的损耗和结温计算。建立了中点箝位型(NPC)三电平变频器电-热耦合模型,通过仿真和实验证明了所提方法的正确性,并分析了基于单开关周期的功率器件瞬态损耗及结温波动情况。

A simplified method for calculating the losses of the three-level inverter and insulated gate bipolar transistor(IGBT)junction temperature is proposed.The conduction and switching loss mathmatical model of the IGBT module is built by experimental data.The power device driving signals are then used to calculate the inverter loss,considering the modulation scheme,load power factor,output current ripples and direct current bus voltage fluctuation,etc.The method is applicable to loss calculation and junction temperature for inverter under any working condition.Moreover,an electro-thermal model of the three level neutral point clamped(NPC)inverter is built.The accuracy of the proposed method is verified by simulation comparison and experiment.The transient losses and variations of the junction temperature based on single switching period power device module during a switching period is analyzed by the proposed method.