Study of Transformer Harmonic Loss Characteristic in Distribution Network Based on Field-Circuit Coupling Method

Round 1

Reviewer 1 Report

Details about your finite element method modelling should be presented. governing equations, boundary conditions, material properties, time steps, etc.

in conclusion section, please present your achievements numerically.

The amount of error between your calculation results and finite element method modelling results should be presented in a table.

Literature review is not enough, please add some papers in this field which are published in the past five years. as an example:

A. Moradnouri, M. Hajiaghapour-Moghimi and M. Vakilian, "A Framework for Economic and Low Harmonic Loss Distribution Transformer Selection based on Ecodesign Directive," 2019 International Power System Conference (PSC), 2019, pp. 19-24, doi: 10.1109/PSC49016.2019.9081493.

Author Response

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Reviewer 2 Report

1* Clarify the term miscellaneous loss.

2* As there are a large number of variables and parameters, authors should provide nomenclature in the first section of paper. It helps the reader to follow the paper conveniently.

3*Equations and their respective numbers are not aligned.

4*The following decision requires more justification. “R(h) can be characterized by using (h)^0.5 Rdc, and jX(h) can be characterized by using jhX(1), corresponding to the 2-hmax order harmonic “

5* Check the following: “Equation (9) shows that when the harmonic voltage acts on the transformer, the harmonic current value generated on both sides of the transformer are very small according to the increase of the transformer reactance, and the winding loss increment generated by the harmonic voltage is negligible. The harmonic current directly produces the harmonic loss on the winding resistance, which increases the winding loss value. Therefore, the transformer harmonic winding loss is mainly related to the harmonic current.”

6*The authors refer to the number of turns of the winding with the letter N and also with the letter W.

7*This is a very exorbitant value: “The silicon steel sheet thickness as 1.2 mm”

8*The authors refer to vector magnetic potential and also vector magnetomotive force using the letter A.

9* Verify equation (19).

1* Indicate units of Figure 4.

1* I print the manuscript to read it and there are figures that require a magnifying glass. Reconsider the size of the figures.

1* Add future work to conclusion section.

1* Check references [1], [8] and [9].

 

1* Many references are from authors who belong to the same region. This is not appropriate.

Author Response

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Reviewer 3 Report

1- The introduction part should be enriched with the inclusion of more previous studies

2-References are not enough

3-Some references should be updated

4-in page 5 line 169-171, the authors wrote (Figure 2 shows that the collecting effect and the adjacent effect of the leakage mag- 169 netic field on the harmonic resistance of the winding becomes gradually larger with the increase of harmonic frequency) an expantion for the reason should be introduced.

5-The equations used in the manuscript should add their references, as it seems to the reader that they belong to or are derived from this study.

6- Authors should add expanation (reasons) of the results in figures 11 and 12.

Author Response

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Reviewer 4 Report

In this paper, the authors presented the effect of harmonic on the core loss and winding loss of transformer was firstly analyzed, then a finite element model of three-phase coherent type distribution transformer was established by using field-circuit coupling method. Finally, the authors have developed the relationships between the core core loss and harmonic voltage, winding loss and harmonic current under the action of each harmonic frequencies were calculated and analyzed, and it was verified that the AC resistance coefficient model is more accurate than the traditional model in calculating the transformer harmonic winding loss. The study is interesting however, i have some points which need to be addressed before acceptance;
1- In the introduction part what is ANSYS finite element algorithm discussed in introduction.

2-Equation 1 can be rearranged into a single line to make it more readable.

3. Discussion related to Figure 2 should be extended to get more insight into the results.

4. Some parts of Figure 6 and Figure 7a and 7b should be more clear and readable you can make axis bold and other changes to make it more readable.

5. Why authors have chosen the harmonic content to be specifically 5%, 7% and 9% and specific reason please elaborate.

6. Discussion related to Figure 8 and 9 should be extended to give more meaningful insight to the results.

 

Author Response

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Round 2

Reviewer 1 Report

In my opinion, now this paper may be published.

Reviewer 2 Report

I see that the authors studied my comments/questions and took them into account to improve their manuscript. No more questions.

Reviewer 4 Report

I am satisfied with changes made in the revised manuscript. Please accept it in its current form.