Hi Fater,
I understand that when you are using a negative angle for abc to dqo transformation you are getting 2nd order harmonics.
You can try the below alternative approach which transforms negative sequence to dq0 components.
- Use a sequence analyser to decompose the three-phase signals into positive, negative, and zero sequences and isolate the negative sequence.
- Apply the abc/dq0 transformation to the isolated negative sequence using the normal angle. This method avoids the introduction of unwanted harmonics.
- After transformation, use a low-pass filter to smooth out any residual oscillations in the dq0 negative sequence components.
Hope this answers your query!
