Optimal design of integrated motor drives - Comparison of topologies (2L/3L/modular), PWM variants, and switch technologies (Si/SiC/GaN)

In this paper, a new design procedure for the optimal design of an integrated motor drive is presented, including an extended iron loss model. The design procedure is based on a multi-objective optimization of power density, efficiency, and cost. In the optimization, a large design space is covered, including the inverter topology, the PWM scheme, the chip technology (Si/SiC/GaN), the winding scheme, the chip area/cost, and the switching frequency. In addition to power density/efficiency/cost, the system reliability is investigated. Considering a 1.5 kW IMD as example, the optimal design in terms of efficiency and cost is achieved using a modular topology, GaN HEMTs, and a 9-phase motor winding. This design enables an efficiency increase of +2.26 % at 36 % higher cost compared to the cost-optimal design that is achieved with the standard 2L-topology, Si IGBTs, and a 3-phase motor winding.