Symmetrical Components / Sequence Components

[laserjet4200]

Hello,

I am working with power systems and I need to work in Symmetrical Components as opposed to working directly with the three individual voltage waveforms.  I am using Labview 7.1.

To convert to Symmetrical Components you normally delay one waveform by 120deg, another by 240deg, then sum with the reference waveform.  My difficulty is two fold.

Firstly, I don't seem to be able to find something similar to Matlab's "Transport Delay" to give me the 120deg phase shift.

Secondly, the frequency will vary, so a constant delay won't work.  In Matlab I was using the "Variable Transport Delay" to overcome this (the delay being preportional to the measured frequency).

Has anyone tried anything similar in Labview before?

Many thanks,

David

[Tom.]

Hello,

Id take a look at this KnowledgeBase article.

Generate a Delayed Waveform from an Acquired Waveform 

Let me know if this helps, after looking at "Variable Transport Delay" on the MathWorks website this looks very similar.

Cheers

Tom | NIUK

[laserjet4200]

Hi Tom,

This looks the business!  Don't think I would have thought of doing it that way myself.

Many thanks.  I'll drop by and leave a note when I get my symmetrical components analyser working.

All the best,

David