基于任务剖面的单相Boost型功率解耦光伏逆变器寿命预测

MISSION PROFILE BASED LIFETIME PREDICTION FOR SINGLE-PHASE BOOST POWER DECOUPLING PHOTOVOLTAIC INVERTER

以单相Boost型功率解耦光伏并网逆变器为研究对象,提出一种基于任务剖面的光伏并网逆变器的寿命预测方法。首先将安装点1年的太阳辐照度和环境温度作为任务剖面,通过PLECS热模型仿真获得不同工况下IGBT的结温数据;然后利用插值查表法得到安装点年任务剖面下对应的IGBT结温剖面,并根据结温循环寿命模型预测单个IGBT的寿命;最后通过蒙特卡罗法计算IGBT的寿命分布函数,并利用串联系统可靠性评估框图得到逆变器系统的寿命分布。计算结果表明逆变器的寿命分布在5年以上,满足ISO 9001质量管理体系认证。

A method based on mission profile is proposed for predicting the lifetime of the single-phase Boost power decoupling photovoltaic grid-connected inverter.Firstly,the annual solar irradiance and ambient temperature of the installation site are taken as the mission profile,and the junction temperature data of IGBT under different operation conditions are obtained through thermal model simulation by PLECS.Then,the corresponding IGBT junction temperature profile under a yearly mission profile of the installation point is simulated by using the interpolation look-up table method.The lifetime of a single IGBT is predicted by the junction temperature cycle lifetime model.Finally,the distribution function of IGBT’s lifetime is calculated through Monte Carlo method,and the lifetime distribution of the inverter system is predicted by the reliability evaluation block diagram of the series system.The simulation results show that the lifetime distribution of the inverter is no less than 5 years,which meets the ISO9001 quality management system certification.