Thermal Modeling of Slotless PM Motor for Industrial Hand Tools

In this paper, a time-efficient steady-state thermal model for a slotless PM motor has been developed. Harmonic losses due to inverter supply are also considered, and the impact of different inverter configurations are investigated. The importance of concentric motor manufacturing process control (enabling a shorter air-gap) is demonstrated from a system point of view. The paper has shown that the total system weight can be reduced by 38 % without performance impairment by deploying a shorter air-gap and carefully considering the inverter configuration.