KBR multimess D9-PQ
20144 EDEBD
A0228-5023-1_EN
62
6.5.5 Interharmonics
The „Interharmonics“ card is used to display all current and voltage interharmo-
nics up to 2,500 Hz online. The measurement data is calculated by the measu-
ring device in accordance with IEC61000-4-30 Class A following the grouping
process and transferred to the PC.
There are three bar charts available:
Interharmonic voltages conductor-earth
Interharmonic voltages conductor-earth
Interharmonic currents
If an interharmonic is selected with the mouse pointer, this measurement value
is displayed in the field on the top right.
Explanation of the grouping process in accordance with the IEC:
To evaluate the interharmonics in the grid, subgroups are created. In each
case, all of the in-terharmonics between two harmonics are combined into one
harmonics subgroup.
Example for 50Hz:
Interharmonic H2 includes all frequencies from 110Hz to 140Hz.
harmonic
subgroup n+1
harmonic
order
DFT
output
n
n+1
n+2
n+3
interharmonic
subgroup n+2,5
Software WinPQ smart