On the surface: convection and radiation
After the heat reaches the external cooling surface A, it is discharged from the object through the external cooling surface A through the convection flux Qconv and the radiation flux Qrad.
In order to minimize the temperature rise, not only should there be A very low thermal resistance Rt, but also the external cooling area A of the object should be as large as possible.
In any electrical component, the total external cooling area should be as large as possible to ensure good heat removal. The ROLINX® bus bar has A large total surface area for its size due to its flat sheet construction. The ROLINX® bus bar can be further optimized to maximize the external cooling area A.
For IGBT modules, the heat loss is seen from another Angle (KW range), and the cooling area is fixed, which is not a design parameter. Only Rt may be affected by the cooling method and fin design in order to accommodate the increased losses with the required system life.
The heat dissipation of medium busbar is in the range of 50W, while the loss generated by IGBT/SiC chips is between 1 and 5kW, so different cooling methods are required. Therefore, the optimal cooling mode is directly related to the total heat loss and the allowable temperature rise.
Typical cooling methods that can affect the outer surface by the typical heat flux Q (the result of dividing the heat eliminated P (W) by the surface area A (dm²)) include:
1. Natural convection: loss Q is within the range of 5W/ DM ² (outer surface) : mobile phones and most other devices; Depends on the allowable temperature rise of the device.
2, forced air cooling: loss in the range of 50W/dm² : heat sink with forced air cooler, or projector.
3, forced water cooling: loss up to 5kW/dm²; IGBT/ silicon carbide module.
Post time: Mar-29-2022