IBA ibaPQU-S, Руководство пользователя

Страница: 28 / 127

Manual ibaPQU-S
28
Issue 1.5
8.3 System integration

Acquisition of the raw values of voltage and current at the input modules

Calculation of the characteristic values in ibaPQU-S

Configuration of the modules, configuration of data recording, acquisition and visu-
alization of the measured and calculated characteristic values in ibaPDA

Transferring the configuration and data with 32Mbit Flex

Analysis, evaluation and if applicable reporting in ibaAnalyzer
8.4 Time synchronization
The ibaPDA computer synchronizes ibaPQU-S with the ibaPDA computer time.
For comparable measurement results which are according to standards, the ibaPDA
computer has to be synchronized.

For more information, see the ibaPDA manual.
8.5 Signal processing
The signals have to be processed in the modules for the standard-compliant calculation
of the characteristic values. This chapter describes the associated effects.
8.5.1 Sampling rate
To calculate the power quality parameters, the ibaPQU-S central unit samples the input
signals in synch with the grid and calculates the characteristic values on this basis. For
this purpose, a synchronization signal (reference signal in ibaPDA) is used and multiplied
to a sampling rate between 30 kHz and 40 kHz. For the nominal frequencies of 50 Hz
and 60 Hz, a sampling rate of 30.72 kHz is set by default and corrected according to the
synchronization signal.
ibaPDA acquires the raw signals on a synchronized time base. Therefore, the signals
are re-sampled internally by ibaPQU-S using the sampling rate set in ibaPDA. As a re-
sult, individual values may not be available or repeated.
ibaPDA sampling
rate ibaPQU sampling
rate Visible signal distortion
1 ms = 1 kHz 30.72 kHz None
0.1 ms = 10 kHz 30.72 kHz Slightly varying slope of the sinus signal
0.05 ms = 20 kHz 30.72 kHz Varying slope of the sinus signal
0.025 ms = 40 kHz 30.72 kHz Values are repeatedly duplicated