MGC
Microgrid controller
The supervisory controller that dispatches sources, storage and loads and manages islanding and reconnection of a microgrid.
SLD / Schematic
Functional block · MRLS
Microgrid reserve-based load shedding
Functional block · Microgrids
An independently authored application reference. The drawing shows the named function or circuit relationship; use the project legend and selected equipment documentation for its drafting form and connections.
Browse this installation focusIn plain English
What this block does
Requests load reduction when the defined operating reserve falls below its assigned requirement.
A simple example
In a microgrid island, the controller can disconnect lower-priority loads when a source is lost and later request restoration when the documented reserve and stability conditions permit it. For this reference, the drawing identifies “Available reserve and requirement” at the input and “Reserve restoration by shedding” at the output. Reserve definitions must include resource constraints.
What the drawings help you do
Start at the named input: Available reserve and requirement. Identify its source device or document and the state represented on the drawing. Follow the named output: Reserve restoration by shedding. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Input
- Available reserve and requirement
- Output
- Reserve restoration by shedding
- Application reference
- An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.
Read the source: Avista Shared Energy Economy microgrid protection and control case study
Schematic · MRLS
What it represents
Requests load reduction when the defined operating reserve falls below its assigned requirement. Load management balances the available electrical supply against the loads that remain connected. Shedding, restoration, priority and proof of disconnection are separate control functions and should remain traceable to individual load groups.
In a microgrid island, the controller can disconnect lower-priority loads when a source is lost and later request restoration when the documented reserve and stability conditions permit it. For this reference, the drawing identifies “Available reserve and requirement” at the input and “Reserve restoration by shedding” at the output. Reserve definitions must include resource constraints.
Identify each load group, priority, measured contribution and feedback. Shedding amounts, operating times and restoration conditions require the approved power-management design and the actual connected-load data. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.
How to read it
- Start at the named input: Available reserve and requirement. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Reserve restoration by shedding. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Reserve definitions must include resource constraints.
- Identify each load group, priority, measured contribution and feedback. Shedding amounts, operating times and restoration conditions require the approved power-management design and the actual connected-load data.
Information to show or reference
- Label the source and connection reference for available reserve and requirement.
- Identify the destination and defined state of reserve restoration by shedding.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Reserve definitions must include resource constraints.
A distinction that matters
Reserve definitions must include resource constraints. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Avista Shared Energy Economy microgrid protection and control case study
Public technical context for microgrid load shedding and restoration. Storage, protection, black start, load restoration and coordinated island operation. The application text and educational graphic are independently authored; the publisher does not certify this representation.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
Explore related references
Put the reference into a drawing workflow.
Elora Grid helps electrical teams work with drawings, specifications and equipment information. Explore the drafting workflow or join the early-access waitlist.