Talk:Direct-quadrature-zero transformation

As introduced in this page, the park transform is different than what appears in Park's original paper " two reaction theory...". This needs to be rectified other wise it leads to confusion. Maybe it could be introduced as it was in the original paper then for implementation purposes could be split into KpKc as done in this page. — Preceding unsigned comment added by 173.66.144.197 (talk) 14:04, 27 March 2024 (UTC)

Elaboration on zero component in Power-variant Form
In the explanation of the Power-variant form of the Clarke transformation matrix, it is explained that "we uniformly apply a scaling factor of √(2/3) and a √(1/radical) to the zero component to get the power-variant Clarke transformation matrix." I think that latter manipulation of applying √(1/radical) to the zero component merits some explanation, it is not obvious to me or most likely other readers where this particular operation is coming from. I believe the article would benefit greatly from a further elaboration on the meaning of the scale of the zero-component axis in the transforms. Jocajo (talk) 00:51, 19 April 2021 (UTC)

modified park transformation
hi Does any body know something about modified park transformation ?
 * Please be more specific. There are variations of the park transformation: different scaling of the transformation matrix (power vs. voltage invariant); the sign of the q axis is sometimes reversed ( $$[-sin(\theta), -sin(\theta-2\pi/3),-sin(\theta+2\pi/3)]$$ vs. $$[sin(\theta), sin(\theta-2\pi/3),sin(\theta+2\pi/3)]$$ ); the d and q axes are sometimes reversed; and the transformation angle, $$\theta$$, may be either zero (the $$\alpha\beta$$ frame, a.k.a Clarke Transformation), the synchronous frame (i.e., the same angle as the voltage or currents, $$\omega t$$, sometimes called the excitation frame), or aligned with the rotor of a synchronous machine or induction machine . The unified view of the dq0 transformation needs to be discussed (i.e. that the synchronous frame, $$\alpha\beta$$ frame, and rotor reference frame are all the same transformation, but with different transformation angle). It would be beneficial to mention common variations of the dq0 transformation in the article, along with references.
 * -- Ap engr (talk) 16:11, 5 June 2013 (UTC)

More explanation needed
The description says In the case of balanced three-phase circuits, application of the dqo transform reduces the three AC quantities to two DC quantities and the graphical interpretation shows the two values I would expect, in phase and in quadrature with the chosen rotation vector.

But the formula given for $$I_{dqo}$$ returns a matrix of three values, not two. Presumably they are $$I_{d}$$ $$I_{q}$$ $$I_{o}$$ from the notation? What is the significance of $$I_{o}$$ ? Is it a zero? it won't be if the three components are unbalanced. Where would it then appear on the diagrams?

I think a little more detail would be informative. --Robert EA Harvey (talk) 15:16, 17 February 2011 (UTC)

The d-q transformation is actually a transformation from three-phase system in which individual phases are shifted for 120 degrees to an orthogonal three dimensional system. Therefore, in general, three phase quantities are transformed into a three-vector orthogonal space. If the original phase quantities are symmetrical (that is, if the vectors lie in one plane) than the zero-order quantity have zero value and this simplifies calculations by transforming three-phases to 3 vector orthogonal system with one zero vector. Since I don't have much time to write detailed explanation and include references someone could expand this and include some better drawings.

- Gasha G. 4/22/2015

The dqo transformation is NOT a transformation from 120 degree shifted abc axis in a plane into a 3D space. It is a transformation from 3D orthogonal abc axis in 3D space (just like xyz) into another set of 3D axis, commonly called alpha-beta-zero, and then rotating alpha-beta axis around zero axis. The article picture showing axis is correct. The common way of putting abc axis in a plane shifted 120 degrees is correct only if the system is balanced, e.g. there is no zero sequence component. If one looks at the 3d cube down the zero axis (main diagonal), the orthogonal abc axis will appear like 120 deg apart. The plane engineers commonly draw three axis 120 deg apart has equation a+b+c=0 in 3D space, which represent balanced system (brush up on vector geometry please). Drawn coplanar axis are projection of 3D orthogonal axis on the plane a+b+c=0. Professor Thomas Lipo of Wisconsin University published a paper that explains all of the above many years ago. I added it as the third reference to the article. — Preceding unsigned comment added by 71.64.194.211 (talk) 03:07, 23 April 2015 (UTC)

why is a common mathematical transform like this being given its own wiki entry?
its like having a seperate wiki entry for the arithmetic involved in calculating ohms law.

Well, there is a separate wiki entry for the Fourier transform. Both the Fourier transform and the DQZ transform are simply mathematical tools. I don't see a difference, and I think it definitely is helpful to have pages dedicated to explaining them. - Dr. David Woodburn 2016-12-10 — Preceding unsigned comment added by 104.129.204.76 (talk) 05:03, 10 December 2016 (UTC)

Suggestion for improvement
In the power variant section, it reads: "a new vector whose components are the same magnitude as the original components: 1". Wouldn't it be better to say "a new vector whose components have the same amplitude as the original components: 1"

Park transform
As introduced in this page, the park transform is different than what appears in Park's original paper " two reaction theory...". This needs to be rectified other wise it leads to confusion. Maybe it could be introduced as it was in the original paper then for implementation purposes could be split into KpKc as done in this page. — Preceding unsigned comment added by 173.66.144.197 (talk) 14:04, 27 March 2024 (UTC)


 * If it is wrong, it should be fixed. If it is just presented differently, then the presentation should follow the form most common in reliable sources. Constant314 (talk) 17:41, 27 March 2024 (UTC)