Functional block · MSSM

Microgrid shedding-group selection matrix

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.

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In plain English

What this block does

Selects a feasible set of assigned controllable groups for the requested load reduction.

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 “Reduction request and group availability” at the input and “Selected shedding groups” at the output. Group power estimates can change during operation.

Reduction request and groupavailabilityMSSMSelected shedding groups
A reading guide. The entry's original illustration and input/output facts describe this application.

What the drawings help you do

Start at the named input: Reduction request and group availability. Identify its source device or document and the state represented on the drawing. Follow the named output: Selected shedding groups. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Reduction request and group availability
Output
Selected shedding groups
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 · MSSMMicrogrid shedding-group selection matrix: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Selects a feasible set of assigned controllable groups for the requested load reduction. 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 “Reduction request and group availability” at the input and “Selected shedding groups” at the output. Group power estimates can change during operation.

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: Reduction request and group availability. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Selected shedding groups. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Group power estimates can change during operation.
  • 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 reduction request and group availability.
  • Identify the destination and defined state of selected shedding groups.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: Group power estimates can change during operation.

A distinction that matters

Group power estimates can change during operation. 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.

SEL · Public reference checked 3 November 2026 · Link only

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.

Entry JSON · Entry Markdown · Last editorial update: 3 November 2026

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