How to get stable sine waveform at higher frequency using "variable Ramp 32 Block"

Altair Forum User

Submitted by keerthi.bhandar... on Sat, 02/23/2013 - 17:40 

 

 

Hi All,

I am unable to generate proper ramp signal & hence proper sinusoidal signal at higher frequencies. My objective is to get a clean & neat ramp signal & sinusoidal signals at frequencies above 150Hz. This is required for me to get reference currents to do a scalar closed loop control. I need to compare the ADC sampled signals with these reference signals at higher frequencies.

I have attached diagram for reference..

Awaiting for some reply... Thanks keerthi

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Altair Forum User

Submitted by Anders89 on Sat, 02/23/2013 - 19:28.

I can see from the status bar in your screen shot that your VisSim sample rate is 100 Hz. By Nyquist sampling theorem you can not produce any signal greater than 50Hz at your sample rate. For a clean 150Hz signal you should sample at least 10x faster than than that. I would choose 2 kHz.
To change sample rate, select System > System Properties... > Time Step and set to .0005

In the future, please attach your .vsm file instead of a screen shot.