Definition
A grid-following inverter is the conventional grid-tied converter found in most solar and battery installations. It controls the AC-side current it injects and synchronizes to the existing grid voltage by tracking the voltage phase angle with a phase-locked loop (PLL). Because it follows an external reference, a grid-following inverter cannot operate on its own: it needs a live, stiff grid (or a separate grid-forming source) to lock onto.
Current-source behavior
Where a grid-forming inverter imposes voltage, a grid-following inverter behaves as a controlled current source that follows voltage. The two are formally described as duals of each other. This design has dominated because it is simple, robust, and ideal for maximizing export to a strong utility grid, but it provides little inherent support to system frequency and contributes nothing to forming or restoring a network during a blackout.
Limits in low-inertia and off-grid settings
As grids host more inverter-based generation, an all-following fleet struggles: with no source actively forming voltage and frequency, stability degrades. A miner running entirely on grid-following inverters has no islanding ability — lose the utility and the inverters trip. Sovereign or microgrid setups therefore pair following inverters with at least one grid-forming source.
See also the grid-forming inverter and rate of change of frequency.
In Simple Terms
A grid-following inverter is the conventional grid-tied converter found in most solar and battery installations. It controls the AC-side current it injects and synchronizes to…