Optimal Thermal Placement and Loss Estimation for Power Electronic Modules

In this paper, a study on loss estimation and optimal thermal placement of power electronic modules is presented. The module is a high-voltage inverter with three separated legs, mostly applicable in electric and hybrid vehicles. The loss is estimated using behavioral model and output waveforms obtained from the simulation in MATLAB. This model has used manufacturer's datasheets in order to facilitate the calculation of heat generation power of both the insulated-gate bipolar transistor and diode. The finite-element (FE) method is used to solve the conductive heat transfer in complex geometry of a three-phase inverter. The heat conduction solution is combined with genetic algorithm (GA) to obtain an effective optimization process of thermal chip placement. In addition, an innovative technique is employed to change the design variables from continuous to discontinuous state and to effectively improve the GA convergence as well as reduce the number of FE simulations. The effectiveness of the proposed method is compared with that of the conventional method, and it shows that both methods resulted in the same optimal placement, whereas FE analysis of the proposed method is about 11.15% of those of conventional methods.