Computationally Efficient Integration of Complex Thernal Multi-Chip Power Module Models into Circuit Simulators

For analyzing reliability or short-term overload conditions of power electronic systems, it is necessary to know transient temperatures of the power semiconductors. Directly coupling thermal and circuit simulators increases the simulation time by orders of magnitude, therefore making such an approach impractical. A well-known solution to this problem is to extract thermal equivalent circuits from 3D-field simulations and to insert them directly into the circuit simulator. In this paper we discuss the poor scaling performance of this state-of-the-art approach. There is an enormous increase in simulation time if there are more than just a few chips thermally modeled. We propose a general procedure at the circuit simulator solver level to increase the calculation speed of such a coupled simulation significantly.