The microgrid is a concept that is modernizing the conventional power system in many countries. It was first proposed in the early 2000s and a lot of research from academia and industry has been conducted to improve the concept as well as the technologies required. Here the definitions of the microgrid are given.
USA Department of Energy (DOE) definition (Ton & Smith, 2012):
"A group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid. A microgrid can connect and disconnect from the grid to enable it to operate in both grid-connected or island mode."
European Union (EU) Research Projects definition (Schwaegerl & Tao, 2013):
"Microgrids comprise LV distribution systems with distributed energy resources (DER) (microturbines, fuel cells, PV, etc.) together with storage devices (flywheels, energy capacitors, and batteries) and flexible loads. Such systems can be operated in a non-autonomous way, if interconnected to the grid, or in an autonomous way, if disconnected from the main grid. The operation of micro sources in the network can provide distinct benefits to the overall system performance, if managed and coordinated efficiently."
From these definitions, the USA DOE definition is widely used in many research and industry literature and projects.
References
Schwaegerl, C., & Tao, L. (2013). The Microgrids Concept. In Microgrids (pp. 1–24). Chichester, United Kingdom: John Wiley and Sons Ltd.
Ton, D. T., & Smith, M. A. (2012). The U.s. department of energy’s microgrid initiative. Electricity Journal, 25(8), 84–94.
