电工技术学报2024，Vol.39Issue(14)：4422-4431,10.DOI:10.19595/j.cnki.1000-6753.tces.230705
并联IGBT占空比的温度特性建模与分析
Modeling and Analysis of Temperature Characteristics of Parallel IGBTs Duty Cycle
摘要
Abstract
IGBT parallel connection effectively solves the problem of increasing the power supply capacity for plasma vertical displacement fast control in Tokamak devices.However,in the working process of parallel devices,due to the inconsistency of device parameters,stray parameters in the circuit,driver parameters,and heat dissipation system parameters between IGBTs,loss differences always exist between parallel IGBTs,resulting in junction temperature differences.The junction temperature difference may increase the loss difference between IGBTs,potentially leading to overheating and failure.However,the existing research mainly focuses on the loss model of a single device or the optimal operating frequency range of parallel IGBTs.The optimal operating duty cycle range of parallel IGBTs is rarely discussed. It is found that when the IGBT device works in the range of a large current positive temperature coefficient,the on-state loss difference ΔEc and the switching loss difference ΔEsw caused by the junction temperature difference ΔTj show different temperature characteristics.Therefore,there is a zero temperature-duty cycle D0,where the duty cycle of parallel IGBTs operates on both sides of the zero temperature-duty cycle.The total loss difference shows two different temperature characteristics,indicating distinct junction temperature mismatch trends.In this paper,the duty cycle range beneficial to IGBT parallel operation is called the optimal duty cycle range. Since the duty cycle is closely related to the operating current of the IGBTs,reasonably improving the loss model of the parallel IGBTs is a challenge to analyze the duty cycle and junction temperature difference.Therefore,taking the BUCK transformation as an example,this paper makes a linear assumption on the switching behavior of parallel IGBTs to simplify the loss model and proposes a zero temperature-duty cycle analysis model.Accordingly,the influence of circuit design parameters,IGBT device parameters,and junction temperature difference on the zero temperature-duty ratio is analyzed.Finally,the existence of a zero temperature-duty ratio is verified by building a double-pulse experimental platform of parallel IGBTs.The following conclusions are drawn: (1)If the duty cycle D is less than the zero temperature-duty cycle D0,the switching loss is less than the on-state loss.The on-state loss is dominant,and the temperature is negative feedback,which benefits the IGBT parallel connection. (2)If the duty cycle D is greater than the zero temperature-duty cycle D0,the switching loss is greater than the on-state loss.The switching loss is dominant,and the temperature is positively fed back,which is not conducive to the IGBT parallel connection. (3)The larger the junction temperature difference ΔTj between the two parallel IGBTs,the smaller the zero temperature-duty cycle D0 is,which is conducive to the parallel operation of IGBTs.关键词
并联IGBT/开关损耗/导通损耗/温度特性/零温度-占空比Key words
Parallel IGBTs/switch loss/conduction loss/temperature characteristic/zero temperature-duty cycle分类
信息技术与安全科学引用本文复制引用
黄海宏,彭岚,王海欣..并联IGBT占空比的温度特性建模与分析[J].电工技术学报,2024,39(14):4422-4431,10.基金项目
国家自然科学基金区域创新发展联合基金资助项目(U22A20225). （U22A20225）
