Development of a 48 V Integrated Starter Generator for Mild Hybrid Vehicles

Abstract

This paper presents the development of a 48 V integrated starter generator (ISG) for mild hybrid vehicles. The motor needs to satisfy power and torque performances requirements under the 48 V system voltage as well as the passenger vehicle’s specific requirements, such as acoustic noise and layout space. Several processes have been explored to obtain a 48 V ISG such as the pole number selection process, the electromagnetic design approach for reducing acoustic noise, and a novel position sensor topology. By using the developed technologies, a 48 V ISG motor is designed, built, and tested. Furthermore, the developed motor is demonstrated to achieve 180 Nm, 15 kW exceeding the 95% motor efficiency with acoustic noise reduction design and thin axial motor length.