{
  "$schema": "https://ps-wiki.github.io/schema/v1/term.schema.json",
  "id": "fast-frequency-response",
  "title": "Fast Frequency Response",
  "description": "FFR. Power in response to frequency changes during the arresting phase",
  "language": "en",
  "tags": [
    "inertia",
    "frequency-control",
    "system-operator"
  ],
  "related": [
    "primary-control",
    "secondary-control",
    "frequency-stability"
  ],
  "breaking": false,
  "dates": {
    "created": "2025-03-15",
    "last_modified": "2025-06-22"
  },
  "authors": [
    {
      "name": "Jinning Wang",
      "url": "https://jinningwang.github.io"
    }
  ],
  "content": {
    "sections": [
      {
        "order": 1,
        "id": "definition-in-a-nerc-webinar-by-ercot",
        "title": "Definition in a NERC Webinar by ERCOT",
        "type": "definition",
        "source_keys": [
          "nerc2020ffr"
        ],
        "page": null,
        "body_md": "> Power injected to (or absorbed from) the grid in response to changes in measured or observed frequency during the **arresting phase** of a frequency excursion event to improve the **frequency nadir** or **initial rate-of-change of frequency**\n"
      }
    ]
  }
}