How to calculate total harmonic distortion for a given signal?
16 views (last 30 days)
Show older comments
Millo Dacha
on 15 Nov 2020
Answered: Joel Van Sickel
on 17 Nov 2020
How to calculate total harmonic distortion for a given signal?
I have used 'spectrum analyzer block' in Simulink and it gives me about 13 percent THD, whereas when I use thd() function in MATLAB script I get around 3.3492e-06 percent.
(Signal is output of a LCL filter which has been fed with output of a sine-PWM inverter.)
3 Comments
Accepted Answer
Joel Van Sickel
on 17 Nov 2020
Hello Millo,
when you used the function, did you only provide the signal data, or did you provide attitional parameters? It is likely you should specificy additonal parameters to get the THD that you want. Please look at the doc page carefully to see what else you can specify: Also, please take into account, that the spectrum analyzer is doing a lot of extra work behind the scenes. This matlab function does not return the value in percent, but in dbc, so you need to convert to percent.
However, I find that using fft, while a bit more work, is also more intuitive to understand what is going on. There are numerous examples of calculating THD in the file exchange. Here is one of them.
Regards,
Joel
0 Comments
More Answers (1)
Rahul Kumar
on 15 Nov 2020
click on powergui block then select FTT analysis after that you find your THD spectra for perticular signal.
0 Comments
Communities
More Answers in the Power Electronics Control
See Also
Categories
Find more on Spectral Measurements in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!