Abstract:

Power Electronics is a multidisciplinary subject that covers many fields. It needs to combine the knowledge of other subjects such as circuit theory, modeling and simulating techniques, various types of electronic and electric components (capacitors, inductors and transformers), etc., in order to be able to convert efficiently and control and condition the electric power. This subject is taught in universities at both undergraduate and postgraduate levels. To take the course students need previous knowledge of circuit theory, electronic technology and design, automatic control and knowledge of computer science as well as knowing how to use advanced applications in personal computers as support for the numerical solutions of circuits and their simulation. While studying this subject, students come across complicated concepts they need to understand and it is here where the visual software such as commercial Finite Element programs are of great interest. As the simulations can be performed in 2D or in 3D ,they allow students to observe and understand the magnetic processes involved in the magnetic components that are included in the power circuits, in particular inductors with ferrite cores with different number of turns and shapes such as E, toroidal, RM and POT. When students carry out a Finite Element simulation of a ferrite inductor excited by a sinusoidal or square waveform, they can analyze and explore the distribution of the magnetic fields and the nonlinear behavior of the core that exhibits saturation and hysteresis, as well as easily change parameters, such as the number of turns, shape and size of the ferrite core and air-gap thickness, among others. Also, as this commercial software includes several specific solvers (electric, magnetic and thermal), students can perform a wide variety of studies. In this paper we present some guidelines and considerations for the correct use of Finite Elements for the modeling of inductors with ferrite cores in educational and investigational contexts. We focus on the election of adaptative meshing and approximations and simplifications that students should perform to achieve convergence. These are necessary as 3D simulations have a high computational cost and often have convergence problems. This procedure is aimed at undergraduate students and postgraduate students beginning their doctorate.

Keywords:

Power Electronics, Nonlinear Inductors, Ferrite cores, Finite Element Analysis, Educational Electronics.