ABSTRACT
An integrated starter generator (ISG) is an electric subsystem in which the functions of the starting engine and the generating electric power are performed by one electric machine on-board the vehicle, instead of two separated electric machines in a traditional automotive vehicle. The early preliminary concept of the ISG can be dated back to the 1930s after the starter was invented in 1911. The ISG is accordingly named integrated starter alternator (ISA). The ISA can be connected with gasoline or diesel engines either through the crankshaft directly or the belt system indirectly. In crank shaft-driven ISA, the rotor of an ISA machine is sometimes served as the flywheel, providing additional mechanical damping function, so that the system can be called ISA damper. If an ISA system is added to the powertrain-level subsystem, a traditional powertrain system becomes a hybrid powertrain system.
