Development of an Engine Starter Generator and Implementation of a Power Efficient Starting Procedure

In this work, the integration of an electric machine into an existing drive train is carried out. The primary goal was to design a machine for starting the internal combustion engine and additionally operating as a generator to deliver electrical power. This motor constellation is referred to as a starter generator. Particular challenging was optimizing the electric machine under limited installation space and existing 12V low-voltage electrical supply. Under the given conditions, a three-phase external rotor synchronous machine with surfacemounted permanent magnets was found to best meet the given requirements. Furthermore, this work also focuses on motor control to optimize the starting procedure of the combustion engine. Self-running speed is achieved even with an electric motor whose maximum torque capability is much lower as the maximum drag torque of the combustion engine.