Highly Integrated Synchronous Reluctance Motor Drive System with SiC-MOSFETs

The design of a highly integrated synchronous reluctance motor drive system with SiC-MOSFETs is presented. The motor-drive-system has a power of 22 kW at 3000 /min rated speed. The power electronics is radially integrated on the motor housing. With the used modular splitting of power electronics (grid side, motor side and HMI side) an equalized distribution of losses around the motor housing is possible. Further on, the position of each module can be defined by customer and in case of failure an easy replacement of any module is possible. Due to the compact design and combined air cooling of motor and drive the overall volume of the drive system (motor + electronics) will be reduced by 25 % applying this new concept compared to the actual solution. In this paper a detailed thermal design approach is presented and comparisons between calculated and measured results are given.