Heat sink design considerations in medium power electronic applications with long power cycles
Paper i proceeding, 2015

The aim of this work is to investigate the impact of the heat sink thickness and material, as well as, of the convection coefficient of the water cooling system on the power-electronics module thermal stressing. The heat extraction capability of different thicknesses is tested. It is concluded that the thickest heat sink results in marginally lower temperature variation at the junction level compared to the second thickest one. In the thickest heat sink case, the linear dependence of the thermal resistance on the thickness counteracts the benefit of the increased thermal capacitance. The increase in the cooling medium flow rate, which corresponds to an increase in the convection coefficient between the heat sink bottom surface and the water, can be avoided by increasing the thickness of the heat sink. In this way, the energy consumption of the cooling system is reduced. The increase in the flow rate drastically reduces the thermal stressing in the thinnest heat sink case. The increase of the heat sink thickness can be beneficial for long power cycles. Copper and aluminum are the two materials that are compared, with the copper heat sink exhibiting a slightly increased performance. The study is conducted for a medium power DC-DC converter of a magnet supply with focus on long power cycles.

Power electronics

Heat convection

Energy utilization

Convection coefficients

Heat sinks


Electric inverters

Electronic cooling

Thermal stressing

Cooling systems

Thermal stress

Power cycling

Heat resistance

Thermoelectric equipment

Lower temperatures

DC-DC converters

Power electronics modules

Thermal capacitance


DC-DC converter

Thermal design

Physics research

Thermal designs


Panagiotis Asimakopoulos

Chalmers, Energi och miljö, Elkraftteknik

K. Papastergiou

European Organization for Nuclear Research

Torbjörn Thiringer

Chalmers, Energi och miljö, Elkraftteknik

Massimo Bongiorno

Chalmers, Energi och miljö, Elkraftteknik

17th European Conference on Power Electronics and Applications, EPE-ECCE Europe 2015, Geneva, Switzerland, 8-10 September