{
  "$schema": "https://ps-wiki.github.io/schema/v1/term.schema.json",
  "id": "control-performance-standard-2",
  "title": "Control Performance Standard 2",
  "description": "CPS2. Inactive. A standard intended to limit unscheduled flows.",
  "language": "en",
  "tags": [
    "frequency-control",
    "nerc"
  ],
  "related": [],
  "breaking": false,
  "dates": {
    "created": "2025-03-15",
    "last_modified": "2026-05-27"
  },
  "authors": [
    {
      "name": "Jinning Wang",
      "url": "https://jinningwang.github.io"
    }
  ],
  "content": {
    "sections": [
      {
        "order": 1,
        "id": "definition-by-nerc",
        "title": "Definition by NERC",
        "type": "definition",
        "source_keys": [
          "nerc2015bal001"
        ],
        "page": "p22",
        "body_md": "> Initially, a 10-minute metric called CPS2 was developed to keep average ACE within specific bounds.\n> CPS2 was originally used to help prevent excessive transmission flows due to large values of ACE.\n> The problem with CPS2 was that it was not dependent on ACE’s impact on frequency.\n> Additionally, CPS2 could cause control actions that moved against frequency.\n> If a BA had very bad performance in one direction for five minutes, the BA could correct this by having equally bad performance in the opposite direction for the next five minutes.\n> Finally, ACE could be totally unbounded for 10% of the month and it didn’t matter whether it was 1 or 1000 MW over the limit.\n> CPS2 did not provide the correct signal for maintaining frequency.\n"
      },
      {
        "order": 2,
        "id": "calculation-by-nerc",
        "title": "Calculation by NERC",
        "type": "note",
        "source_keys": [
          "nerc2015bal0011"
        ],
        "page": null,
        "body_md": "$$\nCPS2 = \\left[ 1 - \\frac{\\text{Violations}_{\\text{month}}}{\\text{Total Periods}_{\\text{month}} - \\text{Unavailable Periods}_{\\text{month}}} \\right] \\times 100\n$$\n"
      }
    ]
  }
}