{
  "node": {
    "id": "term:virtual-temperature-sensor",
    "type": "Term",
    "label": "Virtual temperature sensor",
    "properties": {
      "id": "virtual-temperature-sensor",
      "name": "Virtual temperature sensor",
      "aka": [
        "soft sensor",
        "core temperature estimation",
        "sensorless temperature estimation"
      ],
      "section": "topic-state",
      "definition": "A temperature computed rather than measured: a thermal model fed with current, coolant temperature and the readings of nearby sensors infers the temperature of cells, or cell cores, that carry no sensor. Packs often fit one thermistor for several cells, and a large cell’s core runs hotter than its surface under load, so derating depends on such estimates.",
      "related": [
        "temperature-sensor",
        "thermal-model",
        "derating",
        "bms",
        "digital-twin"
      ],
      "url": "https://lemonergy.com/learn/glossary/virtual-temperature-sensor/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:6555",
      "source": "term:virtual-temperature-sensor",
      "target": "topic:topic-state",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:6556",
      "source": "term:virtual-temperature-sensor",
      "target": "term:temperature-sensor",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6557",
      "source": "term:virtual-temperature-sensor",
      "target": "term:thermal-model",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6558",
      "source": "term:virtual-temperature-sensor",
      "target": "term:derating",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6559",
      "source": "term:virtual-temperature-sensor",
      "target": "term:bms",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:6560",
      "source": "term:virtual-temperature-sensor",
      "target": "term:digital-twin",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-state",
      "type": "Topic",
      "label": "State estimation",
      "properties": {
        "id": "topic-state",
        "name": "State estimation",
        "lede": "The quantities a battery management system estimates but cannot measure directly.",
        "context": "Distinguish internal states from noisy measurement estimates.",
        "example": "Current-sensor bias accumulates in coulomb counting. Exact model SOC does not establish real estimator accuracy.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/capacity-and-c-rate/",
        "lesson_label": "Open charge balance"
      }
    },
    {
      "id": "term:temperature-sensor",
      "type": "Term",
      "label": "Temperature sensor",
      "properties": {
        "id": "temperature-sensor",
        "name": "Temperature sensor",
        "abbr": "NTC",
        "aka": [
          "thermistor"
        ],
        "section": "topic-thermal",
        "definition": "Usually a negative-temperature-coefficient thermistor glued to a busbar or cell surface, with a few per module. Because sensors read the surface, the hottest point inside a cell can run several degrees higher than the BMS sees.",
        "unit": "°C",
        "related": [
          "bms",
          "thermal-management",
          "operating-temperature",
          "derating",
          "thermocouples-rtds",
          "virtual-temperature-sensor"
        ],
        "url": "https://lemonergy.com/learn/glossary/temperature-sensor/",
        "mentions": [
          "busbar"
        ]
      }
    },
    {
      "id": "term:thermal-model",
      "type": "Term",
      "label": "Thermal model",
      "properties": {
        "id": "thermal-model",
        "name": "Thermal model",
        "aka": [
          "lumped thermal model"
        ],
        "section": "topic-thermal",
        "definition": "A model of cell temperature: at its simplest one thermal mass with heat generation inside and convection outside, at its most detailed a 3D simulation of the pack. Temperature feeds back into every rate, so electrical and thermal models are usually solved together.",
        "related": [
          "heat-generation",
          "thermal-management",
          "arrhenius",
          "newman-model",
          "thermal-characterisation"
        ],
        "url": "https://lemonergy.com/learn/glossary/thermal-model/",
        "mentions": [
          "thermal-mass",
          "heat-transfer-modes"
        ]
      }
    },
    {
      "id": "term:derating",
      "type": "Term",
      "label": "Derating",
      "properties": {
        "id": "derating",
        "name": "Derating",
        "section": "topic-pack",
        "definition": "Reducing the allowed charge or discharge power as the battery approaches a limit — low temperature, high temperature, high or low SOC, or age. It is how a BMS keeps the cells safe while letting the vehicle do as much as it can.",
        "related": [
          "state-of-power",
          "bms",
          "operating-temperature",
          "fast-charging",
          "limp-home-mode"
        ],
        "url": "https://lemonergy.com/learn/glossary/derating/",
        "mentions": [
          "state-of-charge"
        ]
      }
    },
    {
      "id": "term:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    },
    {
      "id": "term:digital-twin",
      "type": "Term",
      "label": "Digital twin",
      "properties": {
        "id": "digital-twin",
        "name": "Digital twin",
        "section": "topic-transport",
        "definition": "A model of a specific battery, kept in step with its real counterpart by live data, used to estimate state, predict life and plan operation. The term is used loosely; a model only earns it when it is continuously updated from the asset.",
        "related": [
          "aging-model",
          "state-of-health",
          "bms",
          "remaining-useful-life"
        ],
        "url": "https://lemonergy.com/learn/glossary/digital-twin/",
        "mentions": []
      }
    }
  ]
}