Abstract
Due to the global warming threat, power generation from the renewable sources such as wind and solar are encouraged world wide. On the other hand, the power generated from these renewable engergies depend on weather condition which make the power fluctuates and may cause voltage deviations. This paper analyses the DC smart grid operation in grid connected and isolated mode. The analysed power system consists of wind turbine, photovoltaic, batteries as controllable loads, DC loads and grid converter. To insure the power supply to the critical DC loads for long time as possible in isolated mode, the coordinated load shading was proposed. A DC micro smart grid was modeled and simulated in PSIM (R) card's to show the effectiveness of the proposed method. The simulation results help to analyze the DC smart grid in different operation modes.