3 phase net with ULx

[TBLUgent]

Hello

I have already written a measurement program for a Line Start PMSM, but now I want to create a 3 phase net for the motor. I've bought a USB-3101FS from Measurement Computing. This device creates 4 analog outputs +-10V and it can be programmed via the library ULx. The signal is then amplified with PAS to 3x400V. I already found how I should create 1 phase, but I don't know how to create 3 phases who are 120 degrees delayed from eacht other. Can someone please help me with this?

If this is working, I would like to create disturbances in the net via Labview. Example: voltagedips, harmonic distortion, frequencychanges,...

Dear regards
Thybris Loyson
University of Ghent

[GerdW]

Hi Thybris,

according to specs that device allows for:

- 4 simultaneously updated analog outputs

- 16-bit resolution

- 100 kS/s update rate per channel

It seems you need to setup 3 analog output waveforms with a phase shift between them. Then start to output them at the same clock/trigger…

[TBLUgent]

Thanks for the support.

I'm using this VI right now (see attachement), but I don't know how to install a phase shift between them. I know how I can do it via DAQmx, but I can't find the right function to do this with ULx.

[GerdW]

Hi TBL,

I don't have ULx installed, so cannot comment a lot on your VI.

What I see: You create a single waveform to output on a single AO channel.

What I suggested:

You need to create 3 waveforms for 3 AO channels! (aka: "an array with 3 waveform elements")

And your phase shift between those 3 channels should already be included in the waveforms…

Then you output those 3 waveforms to your 3 AO channels and start them together.

Don't know which features your DAQ hardware provides, NI-DAQ devices usually support start trigger to start several channels at the same time…

[TBLUgent]

Dear GerdW

Now I have created 3 phase (120 degrees phase shift between each other), but now I would like to implement some disturbances (like voltagedips, harmonics, etc...). Do you have any suggestions/examples to do so? The program is attached as "3fasignet_T".

Dear regards

[GerdW]

Hi TBL,

what is the use of those FOR loops? Your code will run without too…

Why do you create 3 waveforms, when your AO output is set to just 2 channels?

[TBLUgent]

Yes thanks. I removed the for-loops and added a third channel (I already did, but I attached the wrong program). 
Here is the new one. 

Could you please help me with the disturbances?

Regards

[GerdW]

Hi TBL,

I would like to implement some disturbances (like voltagedips, harmonics, etc...)

Then you need to add them to your sine wave!

There are a lot more function generator VIs…