Champs,
In C2000 Digital Control Library, DCL 3.1, there are Direct Form 1 - Third order (DF13) and Direct Form 2 - Third order (DF23).
I am confused with them because their difference equations seem same.
u(k) = bo*e(k)+b1*e(k-1)+b2*e(k-2)+b3*e(k-3)-a1*u(k-1)-a2*u(k-2)-a3*u(k-3)
Are they just functionally same but with different implementation of codes?
In order digital power library, we have 3-pole-3-zero codes (CNTL_3P3Z : Three Pole Three Zero Controller).
Which direct form is CNTL_3P3Z in? DF13 or DF23?
Some customers are interested in 3-pole-3-zero compensators for digital power controllers.
Which direct form should they use? DF13 or DF23?
Wayne Huang
