Finite Element CAD Experiments on the Effect of Magnetic Loss in Power Transformers with Laminated Cores

• 作者: Antônio Flavio Licarião Nogueira Rodolfo Lauro Weinert Leonardo José Amador Salas Maldonado
• 来源期刊: 电磁分析与应用期刊(英文)
• 学科: 工学
• 关键词: Eddy Currents Electromagnetic Engineering Education Finite Element Analysis HYSTERESIS Magnetic Loss Transformer Cores
• 年，卷（期）: 2021,（1）
• 页码范围: 1-19
• 页数: 19页
• 分类号: TP3

摘要

The paper describes a simulated experiment that focuses on the numeric computation of magnetic loss in the laminated core of a single-phase power transformer. The students’ laboratory work is part of the library of experiments of the Electrical Machines virtual laboratory and makes use of the two-dimensional open-access electromagnetic field analysis software Finite Element Method Magnetics. The idea of the simulated exercise is to demonstrate how the magnetic loss caused by time-varying excitations affects the magnetic permeability, <em>μ</em>, of the laminated core and the terminal quantities of the energizing winding. A parametric analysis employing different values for the electrical conductivity and maximum hysteresis-induced angle of the laminated material yields five different field problems with increasing magnetic loss. Electric circuits characterized by the (<em>I-V</em>) operating point and reflected impedance of the energizing winding provide the information required to compute the changes in real power Δ<em>P</em>, reactive power Δ<em>Q</em> and magnetically stored energy Δ<em>W</em>_m between successive problems characterized by increasing magnetic loss. The concept of reflected impedance helps to explain the physical meaning of the changes in power dissipation and energy storage in the laminated core.