Power Density Optimization of Two-Level Three-Phase Inverter for DC-Fed Motor Drives

Abstract

A model-based multi-objective optimization has been proposed in this paper to find the optimum switching frequency, modulation method, and semiconductor to maximize both efficiency and power density. Power loss estimations have been done for semiconductors as the primary source, but volume optimizations for DC-Link capacitors, heatsink, and passive components in EMI filter, separately. The analysis has been done for a 30(kW) three-phase two-level inverter for DC-Fed motor drive applications using a model, based on the PLECS thermal model of semiconductors. A maximum 4% difference has been found between the power loss results of the model and PLECS, which was expected due to using average junction temperature in the model to decrease its running time. Optimum switching frequency, modulation methods, and semiconductor comparisons have been reported, as well as the optimum efficiency and power density achieved.