A Dynamic Thermal Model of the Forced Air Cooling Heatsinks and the Optimal Design Closed to the Limit

With the development of high-power density power electronic devices, it becomes more and more significant to design the heatsink with an accurate thermal model. The forced air cooling heatsink could not reach steady-state at the conditions of short-time overloads and burst mode. Therefore, a dynamic thermal model was proposed for the forced air cooling heatsinks, which could predict the dynamic temperature of the heatsink accurately. In this paper, the steady-state and dynamic thermal models of forced air cooling heatsink are optimized considering of spreading effect. The optimized design closed to the limit was proposed based on the dynamic thermal model, which could reduce the volume of the heatsink to 56% of that designed by the conventional method. The experiment shows that the maximum dynamic temperature error of the dynamic thermal model proposed is less than 3.7°C, which proves that the dynamic model proposed has high accuracy.