Multiphase starter generator for 48V mini-hybrid powertrain: Design and testing

The paper focuses on the design and experimental test results of a belt driven starter generator for 48V mini hybrid powertrains. The functionalities required to the system are the engine start up, launch assistant torque, regenerative braking, battery charging and early fuel cut off. The cost effective electrical machine must provide high starting torque and wide constant power range both in motor and generator mode. The authors outline the motivation of the electrical machine topology selection in relation to the specification and constraints. In particular, a double three-phase induction machine has been selected as the suitable candidate. Details of the machine design are presented including a study on multi-layers bar stator windings. Finally, predicted and measured performance of the prototype are reported and discussed.