Finite element analysis of an integrated starter generator (ISG) for four-wheelers using an induction machine

Due to growing considerations regarding environment protection and energy conservation lead us to integrated starter generator (ISG) for the hybrid electrical vehicle. This paper describes a design of induction machine based ISG for four wheeler automobile application. One of the most promising technologies in the automobile industry is the Integrated Starter Generator (ISG) with a high starting torque and able to operate a wide range of speed. The conventional vehicle needs a Starter motor to start the engine and an alternator to generate the power for battery charging. An ISG replaces both the conventional starter motor and alternator in a single machine. Proposed ISG will be developed using Induction Machine. Induction machine does not require brushes, commutator, and earth magnet when compared to claw pole machine (conventional alternator) and DC machine (conventional starter motor). At the time of engine starting power from the battery is converted to AC by an inverter and fed to the machine then it will act as a motor. Once the engine starts to accelerate, speed goes beyond the base speed at that time ISG act as an alternator. An alternator generates the AC power which is converted to DC by diode bridge rectifier and stored in the battery. The compact dimensions allow ISG to be placed between the crankshaft and the engine transmission via a belt. In the proposed Induction machine based ISG model is designed and it is analyzed using MagNet Finite Element Analysis tool. Induction machine based ISG will considerably reduce overall system weight and space in the vehicle.