{
  "$schema": "https://ps-wiki.github.io/schema/v1/term.schema.json",
  "id": "subsynchronous-resonance",
  "title": "Subsynchronous Resonance",
  "description": "SSR. A condition involving energy exchange at natural frequencies below the synchronous frequency.",
  "language": "en",
  "tags": [
    "stability"
  ],
  "related": [
    "oscillation",
    "subsynchronous-oscillation"
  ],
  "breaking": false,
  "dates": {
    "created": "2025-03-15",
    "last_modified": "2026-01-18"
  },
  "authors": [
    {
      "name": "Jinning Wang",
      "url": "https://jinningwang.github.io"
    }
  ],
  "content": {
    "sections": [
      {
        "order": 1,
        "id": "definition-in-an-article",
        "title": "Definition in an Article",
        "type": "definition",
        "source_keys": [
          "ieee1980subsynchronous"
        ],
        "page": null,
        "body_md": "> Subsynchronous resonance is an electric power system condition where the electric network exchanges energy with a turbine generator at one or more of the natural frequencies of the combined system below the synchronous frequency of the system.\n>\n> Subsynchronous resonance encompasses the oscillatory attributes of electrical and mechanical variables associated with turbine-generators when coupled to a series capacitor compensated transmission system, where the oscillatory energy interchange between the electric system and the turbine generator is lightly damped, undamped, or even negatively damped and growing.\n> The terms **subsynchronous** and **supersynchronous** are used to denote frequencies below and above the synchronous frequency defined by rotor average speed.\n"
      }
    ]
  }
}