计及杂散电感的多芯片IGBT模块损耗计算

摘要

Aiming at the issue that packaging stray parameter of insulated gate bipolar transistor (IGBT) module affects the distribution of current and power loss of the internal parallel chips, an IGBT module internal loss calculation method considering the influence of stray inductance is proposed. First, a detailed equivalent circuit model is established based on the internal packaging structure of IGBT module to obtain the influence on the IGBT dynamic characteristics. Then,the function relation between the stray inductance and the proportion of each branch turn-on loss is derived theoretically, based on the corresponding relation between the rate of current changing and the loss distribution. Finally, the phenomenon of turn-on dynamic non-uniform current is simulated and testified, and the effectiveness of the proposed loss calculation method is verified by comparing the result of theoretical calculation and experimental measurement in different loading. Results show that there are obvious current unbalance in the turn-on process of the lower bridge arm of IGBT module,which leads to the difference of loss distribution.%针对绝缘栅双极型晶体管(IGBT)模块封装杂散参数影响内部多芯片并联电流和损耗分布的问题,提出计及杂散电感影响的IGBT模块内部开关损耗计算方法.首先,基于功率模块内部封装结构建立了计及封装杂散电感影响的IGBT等效电路模型,理论推导和分析封装杂散电感对IGBT动态特性的影响.其次,基于开通折线模型中并联芯片间电流变化率与损耗分布对应关系,理论推导了杂散电感分布参数与各支路开通损耗所占比例之间的函数关系,提出计及杂散电感影响的IGBT模块内部开关损耗计算方法.最后,仿真并实验验证了开通过程中IGBT模块内部电流分布规律,测得在不同负载条件下IGBT模块下桥臂各支路损耗并与理论计算结果进行了比较,验证了所提损耗计算方法的有效性.结果表明,IGBT模块下桥臂各并联芯片开通过程中存在明显不均流现象,导致损耗分布存在差异.