To compare the performance of transformers with respect to different core designs based on T-joint configurations of 23º, 45º, 60º, and 90º.

1. THE INFLUENCES OF T-JOINT CORE
DESIGN ON NO-LOAD LOSSES IN
TRANSFORMERS
Guide : Sruthi Nath.S
Asst. Professor
Dept. of EEE
Gokul P K
PIAKEEEO14

2. INTRODUCTION

Transformer Efficiency can be as high as 99%.

Depends on the design of the joints between the limbs
and the yokes.

Performance is compared based
configurations of 23 , 45 , 60 , and 90 .

Flux distribution and loss calculation are analyzed using
Finite Element Method.
on
T-Joint

3. 
Designed and Simulated Using Quick Field Software

To find the best core design based on T-Joint
configuration in terms of No-Load losses and Flux
distribution.

4. A LOOK AT LOSSES

Two types of transformer losses,
1.
2.

Load losses.
No-load losses .
NO Load losses depends on
1.
2.
3.
4.
5.
6.
Type of Joints.
Air gaps.
Overlap area at the Joints.
Accuracy of dimensions (angles at the corner joints).
Flatness of the laminations.
Grade of the material used.

5. 
No load losses do not vary , will be constant over the life time.

Forms less than 1% of the Power Rating.

Represents sizable operating expense, when energy costs are
high.

Can be reduced by understanding localized flux and loss
distributions in the Transformer core.

Alternatively Load losses arise from the resistive components
of the windings.

6. TRANSFORMER CORE LOSSES

Efficiency depends on the type of corner joint between
Yokes and limbs.

Two types of joints,
1.
2.
Mitred Joints
Non-Mitred Joints

Non-Mitred Joints
Transformers.
are
used
in

Here we are considering Mitred joints.
small
rating

7. 
Flux crosses from limb to the yoke along Grain orientation.

Rolling direction of the strip is in the easy direction of
magnetization.

Flux deviates from rolling direction at the corners.

Power losses will increase, as well as the Magneto static and
the noise output of the core.

8. 
Selection of core material affects the performance of
Transformers.

9. TRANSFORMER MODELING
Accurate characterization of the Electromagnetic behavior is
done by Finite Element Method.
Concept of dividing original problem’s domain in to a group of
sub-domains.
Applying Numerical formulation based on Interpolation theory to
the elements.
Quick Field can perform both linear and non-linear Magneto static
analysis.
Modeling of the core design and calculation of No- load losses.

10. CALCULATIONS
No-load loss = Energy
density * f * volume
surface.
Efficiency = Output
power/Input power

11. THE SIMULATION OF TRANSFORMER
DESIGN

14. 
After simulation , we will obtain the output data such as
flux density, flux flow, energy density, permeability etc.

Now we can determine
Transformer losses.

General problem parameters are stored as in the
problem.
winding
Inductance
and

15. DEVELOPMENT

Three stages
1. Geometry description and Manipulation.
2. Definition of properties , Field sources, and boundary
conditions.
3. Mesh Generation

19. RESULT AND DISCUSSION

Results were analyzed according to different core
configurations.

Graphical Representation of Transformer behavior such
as direction of flux, flux density, permeability, energy
density

Four packets consisting of four different angles of T-joint
were analyzed.

22. FLUX DISTRIBUTION
Flux density in the centre limb is maximum.
Due to collection of both left and right flux directions

24. 
Highest flux density was recorded with a 90° T-Joint.

Energy will be stored in regions such as air gaps,
insulation between conductors, and spaces within the
conductors.

Highest Energy density was with a 90° T-joint.

23° and 60° of the T-joint was recorded the highest
values of permeability.

30. 
Loss calculation are achieved using these data

Highest loss was recorded with a 90° and lowest loss
was recorded with a 60° T-Joint.

32. CONCLUSION

Flux distribution and transformer losses have been
investigated for the overall packages.

Observed that
configuration.

Losses increase by internal compressive stresses
through out the yokes and limbs.

A higher energy
transformer losses.
60°
T-Joint
density
is
will
the
optimal
increase
the

33. 
Core losses can be minimized by controlling the flux
distribution.

Adjusting the shape and angle of the core reduces noise
due to the electromagnetic forces.

Small size Transformers with high capacity
performance should be designed in future.
and

34. REFERENCES





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S. V. Kulkarni, and S. A. Khaparde, Transformer Engineering
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39.
J. H. Harlow, Electrical PowerTransformer Engineering. Boca
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35. 
Finite Element Analysis System,Tera Analysis Ltd., QuickField User
Guide,Version 5.7, Svendborg, Denmark,2009.

A. O. Ijaduola, J. R. Thompson, A.Goyal, C. L. H. Thieme, and K.
Marken,“Magnetism and ferromagnetic loss in Ni–W textured
substrates for coated conductors,” Physica C: Supercond., vol.403,
no. 3, pp. 63–171, 2004.
A. O. Ijaduola, J. R. Thompson, A.Goyal, C. L. H. Thieme, and K.
Marken,“Magnetism and ferromagnetic loss in Ni–W textured
substrates for coated conductors,” Physica C: Supercond., vol.403,
no. 3, pp. 63–171, 2004.
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“Estimation of core loss of transformer under non-sinusoidal voltage
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
