Thermal Resistance Matrix Extraction from Finite-Element Analysis for High-Frequency Magnetic Components

Abstract

The thermal management of magnetic components for power electronics is crucial to ensure their reliability. However, conventional thermal models for magnetic components are known to have either poor accuracy or excessive complexity. Contrary to these models, the use of Thermal Resistance Matrices is proposed in this paper instead, which combine both accuracy and simplicity. They are usually used to characterize semiconductor devices, but not for magnetic components. The guidelines to apply Thermal Resistance Matrices for magnetic components are discussed in detail. The accuracy of this model is validated by 3D FEA simulations and experimental results, showing an absolute error lower than 5 ∘C and a relative error between −6.4% and 3.9%, which is outstanding compared to the carried-out literature review.

Influence of Non-Linearity in Losses Estimation of Magnetic Components for DC-DC Converters

“…Since the proposed method works in the time-domain, the wipe out rule method is used: when the derivate of the magnetic flux density dB eff /dt is zero, a maximum B max or a minimum B min value of the actual hysteresis loop is reached and, therefore, the values of B DC and B m are updated for a correct estimation of the power loss. This technique has an important improvement which is of fundamental importance to perform time-domain simulations: in iGSE technique the estimation of the core loss is based on the knowledge of the mean average value of the magnetic flux B(t), while the method described in this section uses the effective magnetic flux B eff which is estimated by using (7). Moreover, this approach can be used in a lumped elements circuit and, also, it allows the SPICE subsystem modeling the inductor to be integrated in a more complex circuit, as shown in Figure 1.…”

“…The latter can result in both non-linear and dynamic behavior, because of the saturation and magnetic hysteresis phenomena [6]. This behavior is, in general, due to the material [7]. Considering the device geometry (i.e., the magnetic core shape), additional complexity arises due to the non-uniform distribution of the magnetic induction field across the core section, and this issue has only been partially investigated [8].…”

Numerical study of heat transfer in high voltage solid insulating materials using transmission line method

“…In the performed studies by De Tommasi et al ( 2018 ) and Salinas et al (2021) , a methodology was developed to extract the thermal resistance matrices from 3 D finite element analysis and thermal simulations. On the other hand, in the proposed TLM model, the variations of insulation temperature are analyzed after the external voltage application.…”

“…Here, the resistance and capacitor elements are physically real, and they are used to model the conductivity and the insulator’s capacitor. On the other hand ( De Tommasi et al , 2018 ; Salinas et al , 2021 ), these elements represent the thermal impedance, and they do not carry the physical realities .…”