What is the Missing Factor in Clarke Transform?

  • Thread starter Thread starter PhysicsTest
  • Start date Start date
  • Tags Tags
    Transform
Click For Summary
The discussion focuses on the derivation of the Clarke Transform, specifically the conversion of three-phase currents (I_a, I_b, I_c) into two-axis components (I_α, I_β). The user identifies a missing factor of 2/3 when comparing their derived equations to the standard equations for I_α and I_β. They seek clarification on the significance of this factor and its necessity in the transformation process. The conversation also touches on the concept of power invariant transformation, as referenced in the Wikipedia explanation. Understanding the role of the 2/3 factor is crucial for accurate application of the Clarke Transform in electrical engineering.
PhysicsTest
Messages
256
Reaction score
27
TL;DR
The Clarke transform equation does not match with my calculations
The standard Clarke Transform is
##
i_{alpha} = i_a; -> 1
i_{beta} = \frac {(i_a + 2i_b)} {\sqrt3} ->2
##
1605953917984.png


I am trying to derive it, but missing a factor. Basically converting the 3 phase currents ## I_a, I_b, I_c ## into the 2 axis ##I_{\alpha}, I_{\beta} ##
resolving along the x-axis
##I_{\alpha} = I_a - I_b \sin(30) - I_c\sin(30) = \frac {3I_a} 2; ## since ##I_a+I_b+I_c=0## -->3
resolving along y-axis
##
I_{\beta} = I_b\cos30 - I_c\cos30; = \frac{\sqrt3(I_a+ 2I_b)} 2 --> 4
##
Now the derived 3 and 4 if i compare with original equations 1, 2, there is a factor ##\frac 2 3## is missing. What is this factor? Why should i include it?
 
Engineering news on Phys.org
Clarke Transformation i found the explanation in the wiki, the Power invariant transformation. What does it mean?
 
I am trying to understand how transferring electric from the powerplant to my house is more effective using high voltage. The suggested explanation that the current is equal to the power supply divided by the voltage, and hence higher voltage leads to lower current and as a result to a lower power loss on the conductives is very confusing me. I know that the current is determined by the voltage and the resistance, and not by a power capability - which defines a limit to the allowable...

Similar threads

  • · Replies 97 ·
4
Replies
97
Views
6K
Replies
7
Views
2K
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 9 ·
Replies
9
Views
779
  • · Replies 8 ·
Replies
8
Views
3K
Replies
9
Views
2K