Use of Dynamic Analysis to Investigate the Behaviour of Short Neutral Sections in the Overhead Line Electrification

Round 1

Reviewer 1 Report

Comments and suggestions for Authors:

In the paper the authors are analysing the neutral sections in AC railway overhead line electrification. Mathematical models for neutral sections were proposed and the results have been satisfactorily checked against laboratory tests. The presented method can be used to optimise the performance of the neutral section.

I think the subject is very interesting and appropriate for the journal, but the paper can be improved. I have several specific comments and questions:

1. Line 70, 92, 126, 168, 180, 199, 529, 531 etc. – The entire paper needs to be checked for formatting, misspelling and grammar issues. The tables and figures format are not consistent.
2. There are abbreviations missing from “Abbreviations and Acronyms” i.e. ATFS, MPATS, TM, ORR, OCL, CB, AF etc
3. The introduction section may be improved with a description of the scope of work/objectives and the novelty of this paper. The authors should identify the existing research gap and they should show their contribution to that research gap.
4. Line 90 – “… is taken from/across two phases of the utility/DNO supply.”
5. Line 92 – This sentence is ambiguous. Please refer to the redundancy provided by the utility/DNO provider.
6. Figure 2 – What is a “major station”? There are a few errors in the figure: i.e. Didcot 400kV substation is connected to a neutral section which is incorrect. Why neutral sections are interconnected with a dot line? There are abbreviations missing from the legend: TM, ATFS, MPATS etc. I suggest redoing the entire figure.
7. Figure 3 – Please add a note stating that D is the neutral section. Also please add a description for “d” and “l” on what they represent.
8. Line 115 – The first sentence is ambiguous. Are the authors referring to different electrical sections?
9. The paper is missing the exact definition and role of the neutral sections in the AC railway systems. The authors can use BS EN 50388 and EN 50367 for guidance.
10. Line 299 – Please provide a description on what the Ansys software is. The readers may not be aware of this software.
11. Line 341 – Please describe the equation.
12. Figure 7 – The text in the figure is of different sizes.
13. Section 6 – I suggest redoing this section and structure it better. The way that the case studies are presented is a little chaotic. It may be useful to add a table with the input data used in the simulations.
14. Section 7 Validation - Please add a short introduction related to exactly what will be validated in this section. It is really confusing what the authors are trying to validate: the techniques? the Ansys software?
15. Table 4 – The title for the first column is missing.
16. The conclusion section should be improved. Please provide specific conclusions from the study conducted.

Author Response

Thank you for your comments please see the attached document for the point-by-point response.

Author Response File: Author Response.docx

Reviewer 2 Report

The paper briefly describes the work undertaken to evaluate the possibility of understanding the behavior and then improving the performance of ‘short’ neutral sections in AC railway overhead line electrification, with particular reference to the UK situation, using a novel approach. The reviewer is impressed with the amount of work that went into this research. That alone gives one hope that a paper worthy of the archival standing of a major academic journal such as this is possible. The paper cannot be accepted in the present form as it needs further improvements.
I. Impressions, impact, add to the knowledge
The article presents an interesting topic however, some points need to be clarified and summarized.
-Abstract: The text must be carefully revised. Some sentences contain mistakes (in the abstract: very general statements), whereas some sentences must be reworded as the English are “meaningless.” I strongly recommend that the authors retain the services of a professional editor. Many reputable companies offer these services.
- In a research paper, it is expected that the introduction section briefly explains the starting background and, even more important, the originality (novelty) and relevancy of the study is well established. Once this is done, the hypothesis and objectives of the study need to be addressed, as well as a brief justification of the conducted methodology.
- The introduction part does not have a flow or direction. It has too many different medical terminologies thrown randomly. Proper references need to be used rather than using others. Language can be improved. The sentences are half-constructed or incomplete so that the readers are expected to fend for themselves to understand their meaning.
- Author must be enriching the references with the latest developments in the field. Some of the recent references can be added. The authors have not paid attention to previous research papers and concerns.
II. Suggestions
- The innovation contribution of this article is not clearly stated. The research contributions should be highlighted in the revised manuscript.
- Many parts are isolated contributions in a manuscript which is otherwise repeated work, and there is no evaluation of these in light of existing information in the literature.
- Abbreviations missing from Abbreviations and Acronyms - ATFS, MPATS, TM, ORR, OCL. Attention is required.
-Line 69, 93, 125, 169, 200, 530 – Check for formatting, misspelling and grammar issues. The tables and figures format are not consistent.
For example:
Line 90 – 92 “… is taken from/across two phases of the utility/DNO supply.” This sentence is ambiguous. Please refer to the redundancy provided by the utility/DNO provider.
Line 115-116 – The first sentence is ambiguous. Are the authors referring to different electrical sections?
Line 300 – Please provide a description on what the Ansys software is. The readers may not be aware of this software.
Line 342 – Please describe the equation.
-Table 4 – The title for the first column is missing.
- Clearly identify the contributions of this particular work with respect to that of others published already. The paper looks like a thesis rather than a research paper.
Discussion Section: Introduce a new section "Discussion", with more current references, which compare the results obtained by the authors with other studies carried out by other researchers.
Conclusions Section: Improve the conclusions section, it is very general and does not clearly explain the main objectives achieved in this research.
The list could go on, but the bottom line is that the authors need to rewrite the paper or even reconsider the research content before it could be considered for publication in this journal. I would recommend ‘Minor revision’ for this paper.

Author Response

Thank you for comments please see the attached document for a point-by-point response

Author Response File: Author Response.docx

Reviewer 3 Report

The paper aimed to analyse dynamic simulation to evaluate neutral sections in the overhead line electrification. The subject is very interesting and fitted into the Infrastructures scope. The objective was achieved, and the paper presentation structure was well. However, three points that I suggest to enrich this paper.  First, the authors must improve the figures and tables presented in order to adjust to the journal template. For example, the tables and the  figurea lines. Also, in the tables are empty gaps and words in wrong gaps.
After that, the authors should include a figure or a flowchart of the methodology applied. This because sometimes, it was difficult to understand the phases of the analysis and the method. 
Finally, the conclusion must be complemented. The article presents some good results, which are no commented on in the conclusion section. Also, it is important to highlight how this paper contributed to the current state of the art.

Author Response

Thank you for your comments, please refer to the attached document for a point-by-point revision 

Author Response File: Author Response.docx

Reviewer 4 Report

Review report of “Title: Use of dynamic analysis to investigate the behaviour of short neutral sections in the Overhead Line Electrification”

The manuscript focuses on an interesting and relevant topic to infrastructure planning and development practice. While the manuscript generally reads well that following consolidations are necessary.

1- Determine a paper type, most likely this is a 'Case Report' but depend on how it is revised it could also be an ‘Article’.

2- Use the suggested abstract structure by the MDPI template. “We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: briefly describe the main methods or treatments applied; (3) Results: summarize the article's main findings; (4) Conclusions: indicate the main conclusions or interpretations. The abstract should be an objective representation of the article and it must not contain results that are not presented and substantiated in the main text and should not exaggerate the main conclusions.”

3- Revisit the referencing style of the reference list.

4- The literature background of the paper is weak. There are no journal articles cited in the paper. Include relevant academic research or review papers to provide a sound literature backing. I’d suggest to enrich the literature with a minimum of 10-12 relevant journal articles.

5- There is a need for Discussion section to address 'so-what?' question.

6- A final language check will be beneficial to improve the readability.

7- This is a promising manuscript, but consolidations are needed to improve its rigour and make it not look like a project but rather an academic article or case report. I look forward to read the revised version.

 

Author Response

Please see attached document which provides detail on how we have responded to each Reviewer

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and suggestions for Authors:

I would like to thank authors for the detailed response. My comments were addressed which improved the paper.

Reviewer 4 Report

the revision has improved the caliber of the manuscript, it can be accepted for publication after the literature background is expanded.