Abstract: Since the late 1970s, intensive efforts have been made to utilise renewable energy sources, such as wind, hydro, solar and tidal. However, the application of individual distributed generators can cause as many problems as it may solve. A better way to realise the emerging potential of distributed generation is to take a system approach that views generation and associated loads as a subsystem or a microgrid. Microgrids are, in fact, modern, small-scale versions of the centralised electricity system. They use distributed energy, which shortens the distance between power source and load, reducing transmission loss. They use renewable energy sources, greatly decreasing carbon emissions. They use energy storage, increasing power supply reliability. They are controlled by power electronic devices, so power sources can vary supply according to demand. Plug-and-play power sources and loads make for a more user-friendly grid. And thanks to real-time monitoring and control technology, every disturbance on a microgrid can be detected and adjusted. In fact, generation and loads can be isolated, keeping a high level of service without harming the gridís integrity.

Keywords: microgrid, protection