ReFreeDrive’s activities progress as we dive into the last months of the project. These last months will be devoted mainly to perform testing activities both at the test benches and on road, with the motor prototypes integrated within a van. With the manufacturing activities reaching its end, it is a perfect time to share with you some insights on the latest technology developed within the project, the induction motor.
The die-cast induction motor design is based on several distinctive features. Regarding the stator, its lamination is conceived to accommodate flat wires. The advantage of flat wire windings with a parallel slot configuration is a much higher copper slot fill factor. Regarding the rotor, it is built using die-casted pure copper; therefore the bars and the end-rings have the same electrical properties. In these motors, the cooling system comprises two elements: a spiral stator water jacket and a spiral shaft groove, both using convection with water-ethylene-glycol mixture as cooling fluid.
Finally, from a performance point of view it is worth remarking that both the 75kW and 200kW are constructively identical, hence the different power outputs are achieved through the appropriate configuration of the Power Electronics for each case.