# Microgrid storage precharge-complete interface

Canonical URL: https://eloragrid.ai/symbols/microgrid-storage-precharge-complete-interface
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: MSPI
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: microgrids
Input: Precharge state
Output: Converter connection readiness

Receives the storage system's documented precharge completion state.

## In plain English

### What this block does

Receives the storage system's documented precharge completion state.

### A simple example

In a microgrid with a battery energy storage system, the controller can request discharge to support a power deficit while the battery management and conversion systems enforce their own operating limits. For this reference, the drawing identifies “Precharge state” at the input and “Converter connection readiness” at the output. The detailed precharge sequence is equipment-specific.

### What the drawings help you do

Start at the named input: Precharge state. Identify its source device or document and the state represented on the drawing. Follow the named output: Converter connection readiness. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Precharge state
- Output: Converter connection readiness
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Precharge state → MSPI → Converter connection readiness
A reading guide. The entry's original illustration and input/output facts describe this application.

- [Avista Shared Energy Economy microgrid protection and control case study](https://selinc.com/api/download/135486/)


## What it represents

Receives the storage system's documented precharge completion state. Storage coordination combines the battery's energy limits with the converter's electrical capability and the microgrid's operating demand. State of charge, allowable power and connection status describe different aspects of availability.
In a microgrid with a battery energy storage system, the controller can request discharge to support a power deficit while the battery management and conversion systems enforce their own operating limits. For this reference, the drawing identifies “Precharge state” at the input and “Converter connection readiness” at the output. The detailed precharge sequence is equipment-specific.
Show which system declares each limit and which controller receives the target. Battery protection, converter capability, thermal management and emergency responses remain with the selected system design. 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: Precharge state. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Converter connection readiness. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- The detailed precharge sequence is equipment-specific.
- Show which system declares each limit and which controller receives the target. Battery protection, converter capability, thermal management and emergency responses remain with the selected system design.

## Information to show or reference

- Label the source and connection reference for precharge state.
- Identify the destination and defined state of converter connection readiness.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: The detailed precharge sequence is equipment-specific.

## Important distinction

The detailed precharge sequence is equipment-specific. 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: Precharge state
- Output / connection: Converter connection readiness
- Lookup label: MSPI is a library lookup label, not a standard device designation.

## Public references

- [Avista Shared Energy Economy microgrid protection and control case study](https://selinc.com/api/download/135486/) — SEL. Public technical context for microgrid storage coordination interfaces. 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.

## 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.