Representative End User Clients
For electricity generation, microgrids typically use some combination of back-up diesel generators and renewables, such as solar panels. Microgrids can incorporate battery systems to store electricity and deploy it during outages or when grid demand spikes. Intelligent software controls can automatically switch the facility between the utility grid and the microgrid based on factors such as power reliability and cost efficiency.
Microgrid Automation
Microgrid automation is a subset of all grid automation, and it's probably about 15% the size of the entire grid. The hardware for microgrids includes inverters, rectifier battery chargers, relays, reclosers, switchgear, circuit protection, power meetings, SCADA, all the switching and communications. Microgrid automation excludes all of the generation equipment, like wind turbines, diesel generators, and solar panels. Also excluded are video surveillance, StepUp transformers, HVAC, and building automation.
The microgrid control consists of three levels: primary, secondary, and tertiary. The first two are associated with the sole operation of the microgrid, while the third is associated with the coordination operation of the microgrid and host network. Conventionally, a hierarchical control is applied in the existing power grids for voltage and frequency regulation and to maintain the power balance.
This hierarchical control scheme for a microgrid consists of three control levels. A multimode operation control for a flexible microgrid is based on a three-layer hierarchical structure consisting of autonomous, cooperative, and scheduling controllers. The droop control is most commonly applied at the primary level. This method is the conventional manner to share the demand power among the generators in a microgrid.
A microgrid can be operated in a centralized or decentralized manner. In the decentralized manner, it is suggested to apply the controllers in distributed nodes forming a distributed control system.