Comparison and review of electric machines for integrated starter alternator applications

The integrated starter generator/alternator (ISG or ISA) uses one machine to replace conventional starter and alternator onboard vehicles. Its stop/restart function and vehicle launch assistance etc helps reduce the fuel consumption and emissions and enhance vehicle performance. The ISA machine is required providing high cranking and launch assistant torque at motoring state and supplying constant voltage to charge the battery at wide speed range. Different electric machines are reviewed and compared in selection of the machines for the ISA applications. The design and operation guidelines of the candidate machine are also given in order to meet the ISA system specifications. Useful conclusions benefit to the development of the ISA technology.