# Microgrid power-surplus detection block

Canonical URL: https://eloragrid.ai/symbols/microgrid-power-surplus-detection-block
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: MPDB
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: microgrids
Input: Generation and absorption capacity
Output: Power-surplus indication

Identifies the defined condition in which available generation exceeds the assigned absorption and load capacity.

## In plain English

### What this block does

Identifies the defined condition in which available generation exceeds the assigned absorption and load capacity.

### A simple example

In a microgrid with solar generation, a battery and generators, the controller can allocate an import/export target among the available resources while reserving the power needed for operating disturbances. For this reference, the drawing identifies “Generation and absorption capacity” at the input and “Power-surplus indication” at the output. Surplus handling requires compatible resources.

### What the drawings help you do

Start at the named input: Generation and absorption capacity. Identify its source device or document and the state represented on the drawing. Follow the named output: Power-surplus indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Generation and absorption capacity
- Output: Power-surplus indication
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Generation and absorption capacity → MPDB → Power-surplus indication
A reading guide. The entry's original illustration and input/output facts describe this application.

- [Microgrid control systems](https://selinc.com/services/microgrids-power-management/microgrid-control-systems/)


## What it represents

Identifies the defined condition in which available generation exceeds the assigned absorption and load capacity. Active-power dispatch allocates the electrical work performed by the microgrid resources. A total site target, a resource power limit and the actual measured contribution are different quantities that must be connected clearly in the diagram.
In a microgrid with solar generation, a battery and generators, the controller can allocate an import/export target among the available resources while reserving the power needed for operating disturbances. For this reference, the drawing identifies “Generation and absorption capacity” at the input and “Power-surplus indication” at the output. Surplus handling requires compatible resources.
Identify the measurement boundary, power sign convention, resource limits and target priority. An original control block does not supply dispatch settings, a financial operating policy or proof of grid-code compliance. 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: Generation and absorption capacity. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Power-surplus indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Surplus handling requires compatible resources.
- Identify the measurement boundary, power sign convention, resource limits and target priority. An original control block does not supply dispatch settings, a financial operating policy or proof of grid-code compliance.

## Information to show or reference

- Label the source and connection reference for generation and absorption capacity.
- Identify the destination and defined state of power-surplus indication.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Surplus handling requires compatible resources.

## Important distinction

Surplus handling requires compatible resources. 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.

## Facts

- Representation: Functional block
- Installation focus: Microgrids
- Input / boundary: Generation and absorption capacity
- Output / connection: Power-surplus indication
- Lookup label: MPDB is a library lookup label, not a standard device designation.

## Public references

- [Microgrid control systems](https://selinc.com/services/microgrids-power-management/microgrid-control-systems/) — SEL. Public technical context for microgrid active-power dispatch controls. Active and reactive power, generation, load control, operating reserves and system supervision. The application text and educational graphic are independently authored; the publisher does not certify this representation.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.