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

Abstract

This paper presents the development of a 48V integrated starter generator (ISG) for mild hybrid vehicles. The motor needs to satisfy power and torque performances requirements under the 48V 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 48V 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 48V ISG motor is designed, built, and tested. Furthermore, the developed motor is demonstrated to achieve 180Nm, 15kW exceeding the 95% motor efficiency with acoustic noise reduction design and thin axial motor length.