Microgrid solutions help tackle major power disruption events due to inherent islanding of a distribution network from a mainstream grid and automatically reconnect it back once the grid is normalized. Besides, they also facilitate and sustain a coordinated integration of renewable sources of power generation with the distribution network.
A microgrid comprises of a group of interconnected loads and distributed energy resources with clearly defined electrical boundaries. It acts as a single controllable entity with respect to the grid and can connect and disconnect from the grid to enable it to operate in both grid-connected or island modes – IEEE 2030.7
It is a localized and a miniature version of the broader power grid network that is self-sufficient and an autonomous energy system, incorporating generation (gas/steam generators, solar, wind combined heat and power), battery storage and demand within a bounded and controlled power network such as:
- Institutional campuses like universities, governmental scientific institutes etc.
- Green townships
- Hospital complexes
- Business centers
- Industrial complexes
A microgrid can be an isolated or a non-isolated type. While an isolated microgrid is permanently in an islanded mode, the non-isolated microgrid can be operated in grid connected or islanded modes.
An isolated microgrid is deployed in areas that are remote from a wider power grid. It needs to ensure continuous and reliable energy supply, without sufficient renewable sources. The choice of power sources often boils down to large storage installations against fuel costs.
Whereas, a non-isolated microgrid can be deployed in rural, semi-urban and urban centers. The main objectives are to ensure supply using dispatchable generation, towards critical load for a pre-determined period when islanded. In this case, the main targets are towards cost optimization using a mix of local generation and energy import from the utility power grid, in compliance to the grid codes set by the DSO or DNO. Also, the key is to shift from an islanded to grid connected mode in a seamless manner, while achieving the desired control objectives.
The Microgrid control system controls the demand response through dispatchable generation and loads and ensures safe, effective, affordable and reliable power supply to consumers.