{
  "node": {
    "id": "term:power-plant-controller",
    "type": "Term",
    "label": "Power plant controller",
    "properties": {
      "id": "power-plant-controller",
      "name": "Power plant controller",
      "abbr": "PPC",
      "aka": [
        "battery plant controller",
        "plant controller",
        "site controller"
      ],
      "section": "topic-data",
      "definition": "The fast closed-loop controller of a grid-connected battery plant that regulates active and reactive power, voltage and frequency response at the point of connection, dispatching setpoints to the inverters. It enforces the grid code, while the energy management system above it decides the schedule.",
      "related": [
        "energy-management-system",
        "inverter",
        "stationary-storage",
        "frequency-regulation",
        "string"
      ],
      "url": "https://lemonergy.com/learn/glossary/power-plant-controller/",
      "mentions": [
        "reactive-power-support"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:5225",
      "source": "term:power-plant-controller",
      "target": "topic:topic-data",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5226",
      "source": "term:power-plant-controller",
      "target": "term:energy-management-system",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5227",
      "source": "term:power-plant-controller",
      "target": "term:inverter",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5228",
      "source": "term:power-plant-controller",
      "target": "term:stationary-storage",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5229",
      "source": "term:power-plant-controller",
      "target": "term:frequency-regulation",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5230",
      "source": "term:power-plant-controller",
      "target": "term:string",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/power-plant-controller/reactive-power-support",
      "source": "term:power-plant-controller",
      "target": "term:reactive-power-support",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-data",
      "type": "Topic",
      "label": "Data, communication and electronics",
      "properties": {
        "id": "topic-data",
        "name": "Data, communication and electronics",
        "lede": "The control units, chips, protocols and file formats through which a battery is measured, controlled and logged.",
        "context": "Separate quantities from encoding and transport.",
        "example": "2500 in a log might mean 25.00 °C, 2.5 V or raw counts. Units and scale must accompany the value.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:energy-management-system",
      "type": "Term",
      "label": "Energy management system",
      "properties": {
        "id": "energy-management-system",
        "name": "Energy management system",
        "abbr": "EMS",
        "section": "topic-pack",
        "definition": "The site-level controller of a storage system that decides when to charge and discharge according to prices, grid signals and the battery’s limits, and dispatches those commands to the BMS and inverters.",
        "related": [
          "bms",
          "inverter",
          "stationary-storage",
          "modbus",
          "energy-arbitrage"
        ],
        "url": "https://lemonergy.com/learn/glossary/energy-management-system/",
        "mentions": []
      }
    },
    {
      "id": "term:inverter",
      "type": "Term",
      "label": "Inverter",
      "properties": {
        "id": "inverter",
        "name": "Inverter",
        "aka": [
          "power conversion system",
          "PCS"
        ],
        "section": "topic-pack",
        "definition": "The power electronics that turn the battery’s DC into AC for a motor or the grid, and back again for charging. In stationary storage it is called the power conversion system and its rating in kW or MW sets the system’s power independently of the battery’s energy.",
        "related": [
          "pre-charge",
          "dc-dc-converter",
          "stationary-storage",
          "energy-management-system",
          "direct-current",
          "iec-62477-1"
        ],
        "url": "https://lemonergy.com/learn/glossary/inverter/",
        "mentions": []
      }
    },
    {
      "id": "term:stationary-storage",
      "type": "Term",
      "label": "Stationary storage",
      "properties": {
        "id": "stationary-storage",
        "name": "Stationary storage",
        "abbr": "BESS",
        "aka": [
          "battery energy storage system",
          "ESS"
        ],
        "section": "topic-applications",
        "definition": "Batteries installed in a fixed place — a container at a solar farm, a cabinet in a home — to shift energy in time or support the grid. LFP cells dominate because cost per cycle and safety matter more than mass.",
        "related": [
          "lfp",
          "energy-management-system",
          "inverter",
          "energy-arbitrage",
          "long-duration-storage",
          "ul-9540a"
        ],
        "url": "https://lemonergy.com/learn/glossary/stationary-storage/",
        "mentions": []
      }
    },
    {
      "id": "term:frequency-regulation",
      "type": "Term",
      "label": "Frequency regulation",
      "properties": {
        "id": "frequency-regulation",
        "name": "Frequency regulation",
        "aka": [
          "ancillary services",
          "frequency response"
        ],
        "section": "topic-applications",
        "definition": "Rapidly injecting or absorbing power to hold the grid frequency at 50 or 60 Hz, a service batteries do better than any generator because they respond in milliseconds. It cycles the battery shallowly but very often.",
        "related": [
          "stationary-storage",
          "energy-arbitrage",
          "specific-power",
          "equivalent-full-cycle",
          "rate-of-change-of-frequency"
        ],
        "url": "https://lemonergy.com/learn/glossary/frequency-regulation/",
        "mentions": []
      }
    },
    {
      "id": "term:string",
      "type": "Term",
      "label": "String",
      "properties": {
        "id": "string",
        "name": "String",
        "aka": [
          "battery string",
          "series string"
        ],
        "section": "topic-pack",
        "definition": "A chain of cells or modules connected in series to reach the system voltage, the basic electrical unit of a large battery. In stationary storage each rack is usually one string of about 1000–1500 V with its own contactors and BMS, and many strings are paralleled on a common DC bus.",
        "related": [
          "series-parallel",
          "pack-voltage",
          "stationary-storage",
          "parallel-string-current-sharing",
          "bms-architecture",
          "contactor"
        ],
        "url": "https://lemonergy.com/learn/glossary/string/",
        "mentions": [
          "bms"
        ]
      }
    },
    {
      "id": "term:reactive-power-support",
      "type": "Term",
      "label": "Reactive power support",
      "properties": {
        "id": "reactive-power-support",
        "name": "Reactive power support",
        "aka": [
          "reactive power",
          "volt-var control",
          "var support"
        ],
        "section": "topic-applications",
        "definition": "Supplying or absorbing reactive power to hold local grid voltage within limits. A battery’s inverter can do it at any state of charge, since reactive power circulates rather than draining stored energy, but it shares the inverter’s apparent-power rating with real power: a 1 MVA inverter exporting 0.8 MW has 0.6 Mvar left.",
        "formula": "S² = P² + Q²",
        "unit": "var",
        "related": [
          "inverter",
          "stationary-storage",
          "frequency-regulation",
          "power"
        ],
        "example": {
          "title": "Read an apparent-power limit",
          "text": "For an ideal converter limited to 10 kVA and operating at 8 kW active power, the circular capability relation allows up to 6 kvar magnitude. Real equipment capability can impose tighter limits."
        },
        "url": "https://lemonergy.com/learn/glossary/reactive-power-support/",
        "mentions": [
          "state-of-charge"
        ]
      }
    }
  ]
}