6.2.2.2 Explanations to the defined measurements

In general, measurements of voltage and current are RMS values calculated over 3 seconds or 10 minutes as described in IEC 61000-4-30. Note: 3s corresponds to 150 cycles on a 50Hz system or 180 cycles on a 60 Hz system.

Energy values are calculated over a period of time, typically 15 minutes, as described in IEC 61577-12.

Values described as minimum or maximum values are calculated over the period since the last reset.

For measurements defined in this companion standard that do not have a specific measurement period, the system integrator or manufacturer may use any period that is appropriate or available.

The BrowseNames of the standardized measurement identifiers follow the following naming conventions:

AcPe: Phase to Neutral

AcPp: Phase to phase

Lp: Low Precision (Float DataType)

Hp: High Precision (Double DataType)

Total: concerns all phases

Sum: concerns the sum of all measured import and export parts (sum = import - export)

Some explanations to the Description text in the table:

Qtot is according to IEC61557-12 [4] the reactive power calculated by the triangle formula, also known as Fryze's definition (harmonics are specified vendor specific)

Qn is according to IEC61557-12 [4] the reactive power calculated according to the Budeanu's harmonic definition (harmonics are specified vendor specific)

Measurements defined to have the DataType Int16[5] represent values as defined in [8].