Control of an Open-Winding Machine in a Grid-Connected Distributed Generation System

In this paper, a grid-connected distributed generation system, which consists of engine-generator, DC link with multiple energy sources, and inverter, is proposed. All six of the stator leads of the generator, which is the surface-mount permanent-magnet machine, are brought out to the terminal of the generator. Three leads are connected to the inverter, and the others are connected to the utility grid. In this proposed system, the power from the engine-generator and the power from DC link can be controlled simultaneously by only one three-phase power converter. Furthermore, the inductance of the generator functions also as the reactor of AC-DC converter. A control algorithm for the system is developed and verified by experimental results.