The Modeling and Simplification of a Thermal Model of a Planar Transformer Based on Internal Power Loss

Abstract

With the development of high-performance wide-band-gap devices and increasing converter frequency, planar transformers are widely used in high-frequency and high-power-density power conversions. Due to the skin effect and proximity effect, accurate thermal analysis and a simplified thermal model of planar transformers are needed for quick thermal verification as well as system design. This paper proposes two thermal simplification models based on the planar transformer’s thermal impedance network. The internal power loss and thermal coupling between each component are first analyzed. Then, based on thermal radiation theory, the simplified thermal model of the planar transformer is presented. It only requires the input of the total power loss of the planar transformer to calculate the temperature rise, and it does not need the power loss of each component. Finally, the simulation and experimental verification are carried out on a MHz prototype.

Investigation of the Temperature Field Distribution in an EI Type Iron-Cored Coil Using 3D FEM Modeling at Different Load Conditions

“…Engineering practice often deals with electromagnetic devices in the form of a currentcarrying coil, which is surrounded by a ferromagnetic core. These devices vary from the view-point of construction and dimension, starting from low frequency small electric transformers for radio-electronic purpose, medium power air or oil-cooled transformers for public service use [1], some special transformers for medium frequency [2] and ending with high frequency planar transformers for special electronic applications [3]. For all of them, the most important task of the designer is to ensure that the coil average temperature will not exceed certain limits [4], which depends on the selected wire, and more specifically, on the thermal properties of any additional electrical insulation used.…”

“…Again, a single heat source is included to energize the scheme, which for that case is acceptable due to the unique coil-core construction. That same idea for a single heat source has also been utilized for the investigation of a high MHz frequency planar transformer [3]. For large oil-immersed power transformers, the problem with a single or divided heat source is presented and discussed in [10,11].…”

A Robust Control Scheme for Dynamic Voltage Restorer with Current Limiting Capability

“…Power quality issues such as voltage dip, voltage swell, unbalance, and harmonic pollution are the main concerns of power grids [1,2]. Nowadays, the integration of the large scale of renewable energy and other nonlinear loads further deteriorates these voltagerelevant power quality issues [3,4].…”