As part of the foundations for a smart grid, the concept and definition of a micro grid has been evolving.
The Micro Grid Institute provides a definition of a micro grid as a small energy system capable of balancing captive supply and demand resources to maintain stable service within a defined boundary.
Further, that micro grids are defined by their function, not by their size and that there a mainly three categories of micro grids:
The isolated islands are used in remote areas as dedicated power generation for a specific application or geographic area. Applications include remote mine sites and townships. The micro grid satisfies the need for electrification. Key requirements are the security of supply, survivability, efficiency and operating costs.
Islandable micro grids are used in either in mission critical applications such as hospitals, data centres or in distributed generation situations where there is a local load. There are coal mines which use gas fuelled generators for both revenue and back-up island operation.
The diverse range of technologies which can be found in micro grids include:
The IEEE 1547 series of standards was developed to provide standards for the interconnecting of distributed resources with electric power systems. The documents provide uniform requirements for the performance, operation, safety, testing and maintenance of the interconnection. The standards apply for the interconnection of 10 MVA or less. A workshop was held in December 2014 to initiate the process of developing the next version of IEEE 1547. One of the questions to be addressed is whether there is a need to expand and include more requirements for islanding (micro grids, Etc.).
In Australia each utility has in-house developed standards for interconnection. There are requirements specified by the Australian Energy Market Operator for systems of 30 MVA or greater, which are connected to the grid.
BESST can provide the power and control system design for micro grid systems, including SCADA networks and system commissioning.