Reserve & Synthetic Inertia

An inverter-based island needs reserve margin and emulated inertia to stay stable when load or generation changes suddenly.

Stability without a flywheel

A conventional grid gets stability partly from the physical inertia of spinning turbine-generators, which resist sudden frequency change. An Aegis island is inverter-based, so it must provide that stabilising behaviour deliberately: through reserve margin held back for contingencies and through synthetic inertia emulated by the power electronics and storage.

Two mechanisms

Reserve is unused generating capability kept available so that a sudden load rise or a unit trip can be met immediately — the +1 unit and part-loaded units provide it. Synthetic inertia is a fast control response: the grid-forming converters and DC-link storage inject or absorb power in the first fractions of a second to arrest frequency excursions, mimicking the physics of a spinning mass.

• Reserve: spare capability held for contingencies
• Synthetic inertia: fast converter + storage response
• Droop: units share sudden changes automatically
• Together: a stable island without large rotating masses

Design-stage status

These are standard grid-forming techniques applied to the Aegis island. Their performance depends on the conditioning and storage design and on validating the machine's transient behaviour — an objective for the test burner, given that the plug operating regime (166–830× beyond any device) means transient dynamics cannot be fully post-dicted today.

The claim is that the architecture provides reserve and emulated inertia, and that demonstrating it is part of the program — not that it is a fielded result. The size of the reserve is set by the largest single contingency the island must survive — typically the loss of one unit — so reserve, redundancy, and storage sizing are solved together rather than in isolation.