How is thermal design performed for power electronic systems?

Thermal design ensures reliable operation within temperature limits. Process: calculate losses (switching + conduction) under worst-case conditions, model thermal network (Rth from junction to ambient), select cooling method (natural convection, forced air, liquid), and size heatsink. Transient thermal analysis uses thermal capacitances for pulsed loads. Key considerations: ambient temperature, altitude derating, thermal interface materials, mounting pressure, and thermal monitoring. Computational tools include thermal FEA and CFD. Design must account for component aging and thermal cycling fatigue.