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 surface-mounted 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.