# Microgrid voltage-control mode selector

Canonical URL: https://eloragrid.ai/symbols/microgrid-voltage-control-mode-selector
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: MVMS
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: microgrids
Input: Mode request and authority
Output: Selected reactive-control mode

Selects the authorized voltage, reactive-power or power-factor operating objective.

## In plain English

### What this block does

Selects the authorized voltage, reactive-power or power-factor operating objective.

### A simple example

In an islanded microgrid, the assigned reference source supports bus voltage while other compatible resources share reactive demand according to the selected control method. Grid-connected operation can use a different objective at the PCC. For this reference, the drawing identifies “Mode request and authority” at the input and “Selected reactive-control mode” at the output. Concurrent control objectives need coordination.

### What the drawings help you do

Start at the named input: Mode request and authority. Identify its source device or document and the state represented on the drawing. Follow the named output: Selected reactive-control mode. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Mode request and authority
- Output: Selected reactive-control mode
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Mode request and authority → MVMS → Selected reactive-control mode
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

Selects the authorized voltage, reactive-power or power-factor operating objective. Voltage and reactive-power control coordinate the AC operating condition of the microgrid resources. A voltage target, reactive-power target and power-factor target represent different control objectives and should have explicit ownership.
In an islanded microgrid, the assigned reference source supports bus voltage while other compatible resources share reactive demand according to the selected control method. Grid-connected operation can use a different objective at the PCC. For this reference, the drawing identifies “Mode request and authority” at the input and “Selected reactive-control mode” at the output. Concurrent control objectives need coordination.
Show each measured quantity, target and resource capability limit. Control-loop tuning, equipment capability and parallel operation require a validated design rather than an assumed property of the symbol. 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: Mode request and authority. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Selected reactive-control mode. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Concurrent control objectives need coordination.
- Show each measured quantity, target and resource capability limit. Control-loop tuning, equipment capability and parallel operation require a validated design rather than an assumed property of the symbol.

## Information to show or reference

- Label the source and connection reference for mode request and authority.
- Identify the destination and defined state of selected reactive-control mode.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Concurrent control objectives need coordination.

## Important distinction

Concurrent control objectives need coordination. 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: Mode request and authority
- Output / connection: Selected reactive-control mode
- Lookup label: MVMS 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 voltage and reactive-power 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.