Sensorless induction machine based integrated starter alternator with loss minimization

This paper presents sensorless integrated starter alternator (ISA) scheme with loss minimization control for the 42 V PowerNet for automobiles. This provides solution for cost and reliability related issues related to position encoder based systems in automobiles. A loss minimization technique is used to obtain the optimal flux command which provide most efficient combination of copper and core loss. The line voltages of induction motor which needs for rotor flux estimation are constructed from DC bus voltage and reference signals of space vector modulator with necessary correction to compensate device drops and dead time effects. This voltage construction will eliminate two voltage sensors and that leads further cost reduction. Dynamics and efficiency improvements of the proposed control scheme in generation mode were investigated using a prototype system.