Three-phase alternating current measurement

Description

A ThreePhaseAcMeasurement entity represents a measurement from an electrical system that uses three-phase alternating current. It has attributes for various electrical measurements such as power, frequency, current and voltage. For some attributes such as current and voltage the value is a structured value with properties for the three different phases: L1, L2 and L3. For some measurements such as the different power types (active, reactive and apparent power) there is an attribute for the total from all phases e.g. totalActivePower and an attribute for values from each phase as a structured value e.g. activePower. There are also attributes for different energy types: active (delivered net energy), reactive and apparent. They are cumulative values and the start time for their measurement can be saved to the dateEnergyMeteringStarted attribute.

For most of the attributes there are various ways they can be actually measured. For this purpose the measurementType metadata attribute can be used. It can have the following values:

  • instant: The value is from the specific instant of time
  • average: The value is the average of a time period
  • rms: The value is the root mean square of a time period
  • maximum: The value is the maximum of a time period
  • minimum: The value is the minimum of a time period

When using the average, rms, mininum or maximum values another metadata attribute called measurementInterval should be used to give the length of the measurement period in seconds. Also the timestamp metadata attribute should be the end time of the measurement period.

Data Model

A JSON Schema corresponding to this data model can be found here.

  • id : Entity's unique identifier.

  • type : It must be equal to ThreePhaseAcMeasurement.

  • source : A sequence of characters giving the source of the entity data.

    • Attribute type: Text or URL
    • Optional
  • dataProvider : Specifies the URL to information about the provider of this information

    • Attribute type: URL
    • Optional
  • name : Name given to the measurement location or target.

  • description : A longer description of the measurement.

  • location : location of the measurement target represented by a GeoJSON point.

  • address : Civic address where the measurement target is located.

  • areaServed : Higher level area to which the measurement target belongs to. It can be used to group per responsible, district, neighbourhood, etc.

  • refDevice : Device(s) used to obtain the measurement.

    • Attribute type: List of Reference to entity(ies) of type Device
    • Optional
  • refTargetDevice : Device(s) for which the measurement was taken.

    • Attribute type: List of Reference to entity(ies) of type Device
    • Optional
  • dateModified : Last update timestamp of this entity.

    • Attribute type: DateTime
    • Read-Only. Automatically generated.
  • dateCreated : Entity's creation timestamp.

    • Attribute type: DateTime
    • Read-Only. Automatically generated.
  • totalActiveEnergyImport : Total energy imported i.e. consumed since metering started (since dateEnergyMeteringStarted).

    • Attribute type: Number
    • Default unit: kilowatt hour (kWh).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • totalReactiveEnergyImport : Total energy imported i.e. consumed (with regards to fundamental frequency reactive power) since the metering start date (dateEnergyMeteringStarted).

    • Attribute type: Number
      • Default unit: kilovolt-ampere-reactive-hour (kVArh).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • totalApparentEnergyImport : Total energy imported i.e. consumed (with regards to apparent power) since the metering start date (dateEnergyMeteringStarted).

    • Attribute type: Number
      • Default unit: kilovolt-ampere-hour (kVAh).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • totalActiveEnergyExport : Total energy exported since metering started (since dateEnergyMeteringStarted).

    • Attribute type: Number
    • Default unit: kilowatt hour (kWh).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • totalReactiveEnergyExport : Total fundamental frequency reactive energy exported since metering started (since dateEnergyMeteringStarted).

    • Attribute type: Number
    • Default unit: kilovolt-ampere-reactive-hour (kVArh).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • totalApparentEnergyExport : Total energy exported (with regards to apparent power) since the metering start date (dateEnergyMeteringStarted).

    • Attribute type: Number
      • Default unit: kilovolt-ampere-hour (kVAh).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • activeEnergyImport : Active energy imported i.e. consumed per phase since the metering start date. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: kilowatt hour (kWh)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • reactiveEnergyImport : Fundamental frequency reactive energy imported i.e. consumed per phase since the metering start date. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: kilovolt-ampere-reactive-hour (kVArh)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • apparentEnergyImport : Apparent energy imported i.e. consumed per phase since the metering start date. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: kilovolt-ampere-hour (kVAh)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • activeEnergyExport : Active energy exported per phase since the metering start date. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: kilowatt hour (kWh)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • reactiveEnergyExport : Fundamental frequency reactive energy exported per phase since the metering start date. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: kilovolt-ampere-reactive-hour (kVArh)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • apparentEnergyExport : Apparent energy exported per phase since the metering start date. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: kilovolt-ampere-hour (kVAh)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
    • Optional
  • dateEnergyMeteringStarted : The starting date for metering energy.

  • frequency : The frequency of the circuit.

    • Attribute type: Number
    • Default unit: Hertz (Hz)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • totalActivePower : Active power consumed (counting all phases)

    • Attribute Type: Number
    • Default unit: watt (W).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • totalReactivePower : Reactive power consumed (counting all phases).

    • Attribute Type: Number
    • Default unit: volt-ampere-reactive (VAr).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • totalApparentPower : Apparent power consumed (counting all phases).

    • Attribute Type: Number
    • Default unit: volt-ampere (VA).
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • activePower : Active power consumed per phase. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: watt (W)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • apparentPower : Apparent power consumed per phase. The actual values will be conveyed by subproperties which names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: volt-ampere (VA)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • reactivePower : Fundamental frequency reactive power. The actual values will be conveyed by subproperties whose names will be equal to the name of each of the alternating current phases: L1, L2, L3.

    • Attribute Type: StructuredValue
    • Default unit: volts-ampere-reactive (VAr)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • totalPowerFactor : Power factor including all phases.

    • Attribute Type: Number
    • Allowed values: A number between -1 and 1.
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
      • onlyPositive: Is the value always greater than zero or can it also be negative. If not present this is assumed to be false.
    • Optional
  • powerFactor : Power factor for each phase. The actual values will be conveyed by one subproperty per alternating current phase: L1, L2 and L3

    • Attribute Type: StructuredValue
    • Allowed values: A number between -1 and 1.
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
      • onlyPositive: Is the value always greater than zero or can it also be negative. If not present this is assumed to be false.
    • Optional
  • totalDisplacementPowerFactor : Displacement power factor including all phases. The quantity is based on the fundamental frequency of the system

    • Attribute Type: Number
    • Allowed values: A number between -1 and 1.
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
      • onlyPositive: Is the value always greater than zero or can it also be negative. If not present this is assumed to be false.
    • Optional
  • displacementPowerFactor : Displacement power factor for each phase. The quantity is based on the fundamental frequency of the system. The actual values will be conveyed by one subproperty per alternating current phase: L1, L2 and L3

    • Attribute Type: StructuredValue
    • Allowed values: A number between -1 and 1.
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
      • onlyPositive: Is the value always greater than zero or can it also be negative. If not present this is assumed to be false.
    • Optional
  • current : Electrical current. The actual values will be conveyed by one subproperty per alternating current phase and the neutral wire: L1, L2, L3 and N.

    • Attribute Type: StructuredValue
    • Default unit: Ampers (A)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • phaseVoltage : The voltage between each phase and neutral conductor. The actual values will be conveyed by one subproperty per alternating current phase: L1, L2 and L3

    • Attribute Type: StructuredValue
    • Default unit: Volts (V)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • phaseToPhaseVoltage : Voltage between phases. A value for each phase pair: phases 1 and 2 (L12), phases 2 and 3 (L32), phases 3 and 1 (L31).

    • Attribute Type: StructuredValue
    • Default unit: Volts (V)
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • thdVoltage : Total harmonic distortion of voltage for each phase. The actual values will be conveyed by one subproperty per alternating current phase: L1, L2 and L3

    • Attribute Type: StructuredValue
    • Allowed values: A number between 0 and 1.
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional
  • thdCurrent : Total harmonic distortion of electrical current. The actual values will be conveyed by one subproperty per alternating current phase: L1, L2 and L3

    • Attribute Type: StructuredValue
    • Allowed values: A number between 0 and 1.
    • Attribute metadata:
      • timestamp: Timestamp when the last update of the attribute happened.
      • measurementType: How the measurement was made. (see beginning of document for details)
        • type: Text
      • measurementInterval: For certain measurement types the measurement period. (See beginning of document for details)
    • Optional

Note: JSON Schemas only capture the NGSI simplified representation, this means that to test the JSON schema examples with a FIWARE NGSI version 2 API implementation, you need to use the keyValues mode (options=keyValues).

Examples

Normalized Example

Normalized NGSI response

{
    "id": "ThreePhaseAcMeasurement:LV3_Ventilation",
    "type": "ThreePhaseAcMeasurement",
    "dateEnergyMeteringStarted": {
        "type": "DateTime",
        "value": "2018-07-07T15:05:59.408Z"
    },
    "refDevice": {
        "type": "Relationship",
        "value": ["Device:eQL-EDF3GL-2006201705"]
    },
    "name": {
        "value": "HKAPK0200"
    },
    "description": {
        "value": "measurement corresponding to the ventilation machine rooms"
    },
    "totalActiveEnergyImport": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            }
        },
        "value": 150781.96448
    },
    "totalReactiveEnergyImport": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            }
        },
        "value": 20490.3392
    },
    "totalActiveEnergyExport": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            }
        },
        "value": 1059.80176
    },
    "totalReactiveEnergyExport": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            }
        },
        "value": 93275.02176
    },
    "totalActivePower": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "value": 31700.269531
    },
    "activePower": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 11996.416016,
            "L2": 9461.501953,
            "L3": 10242.351562
        }
    },
    "totalReactivePower": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "value": -7830.332031
    },
    "reactivePower": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": -2612.606934,
            "L2": -2209.906006,
            "L3": -3007.81958
        }
    },
    "totalApparentPower": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "value": 36019.089844
    },
    "apparentPower": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 13201.412109,
            "L2": 10755.304688,
            "L3": 11941.094727
        }
    },
    "powerFactor": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            },
            "onlyPositive": {
                "value": true
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 0.908817,
            "L2": 0.879906,
            "L3": 0.859293
        }
    },
    "displacementPowerFactor": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            },
            "onlyPositive": {
                "value": true
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 0.978013,
            "L2": 0.973317,
            "L3": 0.960382
        }
    },
    "frequency": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "value": 50.020672
    },
    "current": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "rms"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 56.126038,
            "L2": 45.894356,
            "L3": 50.872452,
            "N": 0.0
        }
    },
    "phaseVoltage": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "rms"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 234.961304,
            "L2": 234.563477,
            "L3": 235.354034
        }
    },
    "phaseToPhaseVoltage": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "rms"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L12": 406.769196,
            "L23": 407.081238,
            "L31": 407.734558
        }
    },
    "thdVoltage": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 0.01471114,
            "L2": 0.01600046,
            "L3": 0.01541459
        }
    },
    "thdCurrent": {
        "metadata": {
            "timestamp": {
                "type": "DateTime",
                "value": "2019-01-24T22:00:00.173Z"
            },
            "measurementType": {
                "value": "average"
            },
            "measurementInterval": {
                "value": 1
            }
        },
        "type": "StructuredValue",
        "value": {
            "L1": 0.38497337,
            "L2": 0.45807529,
            "L3": 0.4938652
        }
    }
}

key-value pairs Example

Sample uses simplified representation for data consumers ?options=keyValues

{
    "id": "ThreePhaseAcMeasurement:LV3_Ventilation",
    "type": "ThreePhaseAcMeasurement",
    "dateEnergyMeteringStarted": "2018-07-07T15:05:59.408Z",
    "refDevice": ["Device:eQL-EDF3GL-2006201705"],
    "name": "HKAPK0200",
    "description": "measurement corresponding to the ventilation machine rooms",
    "totalActiveEnergyImport": 150781.96448,
    "totalReactiveEnergyImport": 20490.3392,
    "totalActiveEnergyExport": 1059.80176,
    "totalReactiveEnergyExport": 93275.02176,
    "totalActivePower": 31700.269531,
    "activePower": {
        "L1": 11996.416016,
        "L2": 9461.501953,
        "L3": 10242.351562
    },
    "totalReactivePower": -7830.332031,
    "reactivePower": {
        "L1": -2612.606934,
        "L2": -2209.906006,
        "L3": -3007.81958
    },
    "totalApparentPower": 36019.089844,
    "apparentPower": {
        "L1": 13201.412109,
        "L2": 10755.304688,
        "L3": 11941.094727
    },
    "powerFactor": {
        "L1": 0.908817,
        "L2": 0.879906,
        "L3": 0.859293
    },
    "displacementPowerFactor": {
        "L1": 0.978013,
        "L2": 0.973317,
        "L3": 0.960382
    },
    "frequency": 50.020672,
    "current": {
        "L1": 56.126038,
        "L2": 45.894356,
        "L3": 50.872452,
        "N": 0.0
    },
    "phaseVoltage": {
        "L1": 234.961304,
        "L2": 234.563477,
        "L3": 235.354034
    },
    "phaseToPhaseVoltage": {
        "L12": 406.769196,
        "L23": 407.081238,
        "L31": 407.734558
    },
    "thdVoltage": {
        "L1": 0.01471114,
        "L2": 0.01600046,
        "L3": 0.01541459
    },
    "thdCurrent": {
        "L1": 0.38497337,
        "L2": 0.45807529,
        "L3": 0.4938652
    }
}

Test it with a real service

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