电工技术学报2024，Vol.39Issue(14)：4508-4518,11.DOI:10.19595/j.cnki.1000-6753.tces.230847
计及金属化薄膜电容器与IGBT模块退化过程相关性的柔直换流阀组件可靠性评估方法
Reliability Evaluation Method for VSC-HVDC Valve Submodules Considering the Correlation between the Degradation Process of Metallized Polypropylene Film Capacitors and IGBT Modules
摘要
Abstract
Flexible DC transmission technology can rapidly and flexibly control active and reactive power in large-scale new energy power transmission,providing voltage support to weak AC or passive systems.With the increasing demand for system capacity and the expansion of engineering application scenarios,it is of great engineering significance to accurately and real-time evaluate the operational reliability of flexible and direct converter valves as core equipment.However,most existing reliability assessment methods focus on modeling the reliability of key components such as IGBT modules and metalized thin film capacitors,neglecting the coupling relationship between component degradation processes.Previous studies have shown that capacitor capacity degradation causes an increase in IGBT module switching frequency,affecting the reliability of IGBT modules.Therefore,this paper proposes a reliability evaluation method for flexible direct converter valves,considering the correlation between the degradation process of capacitors and IGBT modules.Copula theory is used to model the coupling relationship between capacity degradation and IGBT module life,improving the accuracy of reliability evaluation results for flexible direct converter valves. The reliability evaluation of IGBT modules considers the influence of typical mission profiles of flexible and direct converter valves,and the life distribution adopts the Weibull distribution model.The IGBT module losses include static and dynamic losses.Static losses include IGBT on-state losses,IGBT off-state losses,diode on-state losses,and diode off-state losses.Athermal network model is established using the principle of electrical analogy,which includes heat sinks,ambient temperature,and device packaging structure.The junction temperature of the IGBT is calculated.The variable amplitude load is converted into a complete cycle of a series of transverse thermal loads using statistical notation.According to the linear damage principle,the cumulative life loss of IGBT is calculated.Device manufacturers,such as ABB and Infineon,indicate that the reliability of IGBT follows a Weibull distribution through accelerated aging experiments.Finally,the reliability function of IGBT modules can be obtained.Based on the monitoring data of capacity degradation,a reliability evaluation model for metalized thin film capacitors is established based on the wiener process.The Wiener process is a stochastic process with a linear drift term,where the capacitance tends to decrease due to the accumulation of many minor self-healing points.The maximum likelihood estimation value is obtained by estimating wiener distribution parameters through accumulated monitoring data of capacitor capacity degradation. The capacitance of the capacitor declines over a long period of operation,increasing the switching frequency of the component IGBT where it is located,while other components'switching frequency on the same bridge arm IGBT almost remains unchanged.The correlation is modeled using a two-dimensional Gumbel-type Copula function.The proposed method is more accurate than existing reliability evaluation methods.The average time between failures of flexible and direct converter valves has been revised from 4.05 to 5.20 years.关键词
柔性直流换流阀/可靠性评估/金属化薄膜电容器/IGBT模块/Copula理论Key words
Modular multilevel converter(MMC)/reliability evaluation/metallized polypropylene film(MPPF)capacitor/IGBT module/Copula theory分类
信息技术与安全科学引用本文复制引用
张午宇,齐磊,张翔宇,崔翔,郭宁明..计及金属化薄膜电容器与IGBT模块退化过程相关性的柔直换流阀组件可靠性评估方法[J].电工技术学报,2024,39(14):4508-4518,11.基金项目
国家电网有限公司科技资助项目(5500-202140126A-0-0-00). （5500-202140126A-0-0-00）
