A robust integrated starter/alternator drive adopting a synchronous reluctance machine for automotive applications

A synchronous reluctance machine is investigated as a promising solution for integrated starter/alternator applications. For this application the electric machine should exhibit a high torque during the engine start-up and a wide constant-power speed range during electric energy generation. Peculiarities of the synchronous reluctance machine are the possibility of a large torque overload at low speed, its extended flux-weakening capability, and its inherent fault-tolerance. In details, this paper reports the design of the electric machine, the results of finite-element computations, the description of the control system, and the experimental test measurements on the drive prototype.