How can I calculate the Harmonics Complex Spectra of a Power Substation using a cDAQ or cRIO Chassis?

Updated May 31, 2018

Reported In

Hardware

  • cRIO-9068
  • cRIO-9082
  • cRIO-9074
  • NI-9225
  • NI-9227
  • NI-9242
  • NI-9244

Software

  • LabVIEW Electrical Power Toolkit

Issue Details

I have a power substation with a Single-Bus Single-Line, Single-Bus Multiple-Line or Multiple-Bus Configuration.
I am acquiring the voltage and current of the lines using a cDAQ or cRIO chassis to analyse the power quality of the substation.
How can I calculate the magnitude and phase of the harmonic complex spectra?

Solution

The spectra acquisition depends on the configuration of the Substation. In both Single-Bus configurations you can measure nominal voltage in any line since it's equal across the bus, however the currents can be different.
In the Multiple-bus configuration the voltages and currents may vary among different buses.

Once acquired the spectra in the appropiate lines, you can use the Group Spectrum Lines VI of the Electrical Power Toolkit to group and calculate the complex spectra of harmonic and interharmonic subgroups in both single-line and multiple-line systems.

Then use the Complex To Polar function to convert the results to magnitude and phase or the Complex To Re/Im function to convert to real and imaginary spectra.

 

Additional Information

Depending on the hardware you are using, refer to the following examples of the Electrical Power Toolkit using the Group Spectrum Lines VI:

Harmonics Analysis (DAQmx) VI: labview\examples\Electrical Power\Power Quality\Applications (DAQmx)

Harmonics Analysis VI: labview\examples\Electrical Power\Power Quality\Applications (cRIO) (Delta-Sigma)

Harmonics Analysis VI: labview\examples\Electrical Power\Power Quality\Applications (cRIO) (SAR)

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