热点温度是影响金属化薄膜电容器(metallized film capacitors,MFC)绝缘寿命的重要因素之一,但由于其无法直接测量,因此通常采用热仿真分析或温度反演的方法获得.该文提出了基于共轭梯度法(conjugate gradient method,CG)的热点温度反演模型,建立了内部传热过程的温度分布目标函数,采用有限差分法求解电容器温度场,再通过CG对内部温度分布进行迭代求解.同时,通过交流温升试验校核了仿真模型以及反演模型.研究结果表明:热点温升与表面温升存在线性关系,热点温度出现在 MFC 中央靠近芯轴处,反演模型与仿真模型最大误差为4.35%,说明该模型可实现现场工况下的温度分布、热点分布等的有效预测.
Hot-spot Temperature Inversion for Metallized Film Capacitors Based on Conjugate Gradient Method
Hot-spot temperature is one of the important factors affecting the insulation life of metallized film capacitors,because it can not be measured directly but be usually obtained by thermal simulation analysis or temperature inversion.This paper proposes a hot-spot temperature inversion model based on the conjugate gradient method(CG).The inversion model establishes the temperature distribution objective function of the internal heat transfer process,adopts the finite difference method to solve the capacitor temperature field,and adopts CG to analyze the internal temperature distribution by iterative solution.At the same time,an AC temperature rise test is carried out to check the simulation model and the inversion model.The results show that there is a linear relationship between the hot-spot temperature rise and the surface temperature rise,the hot-spot temperature appears in the center of the MFC near the mandrel,and the maximum error between the inversion and the simulation model is 4.35%,which indicates that the model can realize the effective predic-tion of temperature distribution and hot-spot distribution under field working conditions.
metallized film capacitorsinversion modelhot-spot temperature risesurface temperature riseconjugate gradient method
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维普
