Design and Analysis of a Novel Integrated Starter-Generator Based on Brush DC Motor

The conventional brushless integrated starter-generator used for the power supply system is driven by the power electronic converter, which would be composed of many controllable electronic switching devices in parallel when the system runs in high current conditions. As a result, it complicates the structure and control of the system, occupies the limited volume, and increases cost. Thus, a novel integrated starter-generator based on a conventional brush DC motor is proposed in this paper. It changes the concentrated stator winding of the DC motor to a distributed winding. At starting mode, the machine uses the stator winding as field winding and adopts an electric brush for commutation. At generating mode, the machine uses the rotor winding as field winding, and a slip ring is used to provide a DC excitation current. In this way, the machine can function as a DC motor and a synchronous generator. The basic structure and working principle of the machine are described in detail, and the feasibility of the scheme is verified by finite element analysis (FEA) results.