Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

GFM

Symbols

Grid-forming inverter

A grid-forming inverter controls its output as a voltage source behind an impedance, setting voltage magnitude and frequency itself rather than measuring and following them. This lets it start a dead microgrid, share load with other sources through droop or virtual synchronous machine control, and respond instantly to load steps.

Drawing use: SLD
Application: Microgrid systems
Reference family: IEC / IEEE / ANSI

A distinction that matters

A grid-forming inverter sets voltage and frequency; a grid-following inverter injects current synchronised to a voltage that something else provides.

Full reference

GFL

Symbols

Grid-following inverter

A grid-following inverter measures the network voltage, locks to it with a phase-locked loop and injects a controlled current. Most rooftop and utility-scale solar inverters work this way. They need a stable voltage from the grid, a synchronous machine or a grid-forming inverter to operate, and they disconnect when that reference is lost.

Drawing use: SLD
Application: Microgrid systems
Reference family: IEC / IEEE / ANSI

A distinction that matters

A grid-following inverter needs an external voltage reference; a grid-forming inverter provides that reference.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.