# Microgrid power-deficit detection block

Canonical URL: https://eloragrid.ai/symbols/microgrid-power-deficit-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: Demand and available supply
Output: Power-deficit indication

Compares assigned demand with available supply under the defined island or connected condition.

## In plain English

### What this block does

Compares assigned demand with available supply under the defined island or connected condition.

### 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 “Demand and available supply” at the input and “Power-deficit indication” at the output. Measurement and estimation errors affect the result.

### What the drawings help you do

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

### Terms

- Input: Demand and available supply
- Output: Power-deficit indication
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Demand and available supply → MPDB → Power-deficit 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

Compares assigned demand with available supply under the defined island or connected condition. 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 “Demand and available supply” at the input and “Power-deficit indication” at the output. Measurement and estimation errors affect the result.
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: Demand and available supply. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Power-deficit indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Measurement and estimation errors affect the result.
- 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 demand and available supply.
- Identify the destination and defined state of power-deficit indication.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Measurement and estimation errors affect the result.

## Important distinction

Measurement and estimation errors affect the result. 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: Demand and available supply
- Output / connection: Power-deficit 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.