Integration of renewable energy generation with conventional diesel-engine powered generation in a microgrid

In this paper, integration of solar panel based renewable energy distributed generation (DG) with conventional diesel-engine generator in a microgrid has been studied in both grid-connected and islanded modes. Besides solar energy based DG and diesel generator, a grid-forming and a grid-supporting distributed generators are also included in the microgrid. The grid-forming DG adopts constant frequency control and decoupled PQ control with self-generated reference voltage while the grid-supporting DG adopts PQ control with its reference voltage taken from its terminal in microgrid. It is found that the conventional diesel-engine based synchronous generator with terminal voltage and frequency control can operate harmoniously with grid-forming, grid-supporting and renewable energy DGs in both grid-connected and islanded modes and also during islanding. Furthermore this paper also tested that when the diesel generators disconnects from microgrid, the left part of the microgrid still can operate to reach its new equilibrium.