General Analytical Model for the Thermal Resistance of Windings Made of Solid or Litz Wire

Design of highly compact short‐time duty power inductors for supercapacitor charging applications

“…11 as an illustrative case of the modelling process of the conduction thermal resistance. Assuming that the horizontal heat transfer and the vertical one are independent of each other, a single wire can be equivalent to a four‐thermal‐resistance model [16], which only includes copper and insulating materials (polymide, Nomex paper, and resin). Between the two adjacent turns in the horizontal direction, there are a conduction path along the conductor (average length nMLT ) and a path through the insulating material.…”

“…Since the object inductor works under water‐cooling for a short time each time, the transient thermal performance and related influencing factors are the most concerned. The empirical formulas in [15] are widely used, however, it can only be used to roughly estimate the steady‐state temperature because of the over‐simplification. In [16], the analytical model for the thermal resistance of windings made of solid or Litz wire is described in detail. The authors in [17, 18] established a transient thermal model for oil‐immersed line‐frequency transformers, which is used to predict the top oil temperature.…”

Numerical Approach to Determining Windings' Thermal Conductivity

“…There are some authors who investigated the windings' equivalent thermal conductivities or contributed to the modeling of windings' in a realistic approximation [10], [11]. Other works provided analytical correlations or methods for windings made of Litz wires [12], [13]. In the former, the authors determined the thermal conductivity of Litz wires' windings in terms of different thermal and geometrical characteristics of the slot composition, based on the analogy between electrostatics and heat transfer.…”

Thermal modelling of high-frequency magnetic components for power electronics by Finite Element Analysis

“…The thermo-electrostatic field analogy proposed by Jaritz et al [39] shows a deviation with experimental measurements in the band of [1.3, 12.5] %. It shows good accuracy, but it might be complex.…”

“…As stated in the review from Pietrak et al in [33], some of the previous approaches can be used to get the effective (equivalent) thermal conductivity which is the magnitude of interest of the present work. And more particularly, they are perfectly suitable to homogenize electrical litz bundles for electrical machines [34]- [38] and inductors or transformers for power converters [39], [40]. The effective thermal conductivity, k w , calculated by these approaches will govern the heat equation,…”