Real-Time Control Strategy of Fuel Cell and Battery System for Electric Hybrid Boat Application

Round 1

Reviewer 1 Report

Dear Authors,

I think it is of an author's best interest to have a review with the highest amount of fair-criticism as possible, thus having his/her name associated with high-quality work. Minding the time constraints to review this paper, I spent the maximum amount of time I could on it and tried to be as critical as I could.

1. Abstract: Lines 11-14: Why you use the abreviation (FC) in line 13? You must try to write your abstract without abreviations. This is a typical format of all journals and conferences.
2. Abstract: Line 21: You refer to dSPACE board. Is this the typical processor? You refer a cost-effective entry-level system with I/O interfaces?
3. Introduction: Lines 26-27: Which are these reports, in which you refer to? Please add the appropriate references. You have only 1 in this paragraph.
4. You should check again your English style in your work. For example "alternative clean energy such us fuel cells". It is not "us" but it is "as"! Of course there are many more English style mistakes. Please fix it.
5.  Introduction: Line 33: Why you do not use the abreviation (FC) for fuel cell?
6.  In Lines 33-41: Please add a reference. It is a little bit weak! You write a phrase and the reader cannot find a related reference.
7. In Lines 42-45: "Most of these researches" You refer to many researchers and you have only one reference. Why? There are many works related to HEV.
8. In Line 49: You refer to a non-linear system. Which are the main characteristics of this system? Please explain more!
9. In Lines 57-59: "However, most of these researches have not tested experimentally and might not actually represent the physical operation of the system because of modeling assumptions and approximations." Which are these works? Please add the appropriate references. It is a scientific journal!
10. In Line 92 : "The studied HEB system presented in Error! Reference source not found." It is inappropriate to send a work without check it again and again. Where is the reference?
11. I cannot find how you refer to your figures in your text. Please fix it.  For example: "The dc grid is connected to the FC through one directional interleaved boost converter and pack of batteries power source through buck-boost DC-DC converter. The variable load has linked to the DC-AC inverter" as shown in Fig. 1.  The reader will have difficulties to understand which phrase refer to which Figure! Please fix it!
12.  The text (labels, symbols, etc) in your Figures are very tiny. Please fix them. 
13. Lines 141-143: Please re-write these phrases.  You should write that [V] is the measurement unit. For example  ??? is the fuel cell voltage (measured in V), etc. 
14. You write 13 mathematical equations. Please explain the necessity of them in your work. I cannot understand where you use them.
15. Please use a professional programm for the implementations of the schematics. For example inkscape. It will upgrade your work.
16.  In Table 1, please explain how you calculate or how you find all these parameters? 
17.  Please fix all the format and style problems of your work. I have difficulties to read and understand the novelty!
18. Please add extra references. Your work is a little bit weak with only 16.

Author Response

Dear Reviewer,

We would like to thank reviewer for taking the time and effort necessary to review our manuscript. We sincerely appreciate all valuable comments and suggestions, which helped us to improve the quality of our manuscript. Please find attached our responds for your comments.

Author Response File: Author Response.pdf

Reviewer 2 Report

Firstly, I would like to thank you Sustainability which gave me the opportunity to review this very interesting paper. This manuscript does an excellent job demonstrating significant strain differences in real-time monitoring Strategy of Fuel Cell and Batteries System for Hybrid Boat Application. This work presents a paradigm that can be broadly and usefully applied.

What I really believe is missing from this paper is the authors to analyze more how real-time monitoring can contribute to the reduction of environmental impacts.

Author Response

Dear Reviewer,

We would like to thanks the reviewer for this careful reading of our manuscript and thoughtful comments. Attached, we have addressed their questions and comments and indicated the changes in the manuscript (highlighted in red in the revised text).

Author Response File: Author Response.pdf

Reviewer 3 Report

In this paper, the authors proposed a real-time control strategy of fuel cell and batteries for hybrid boat applications. The topic and proposed method can be interesting to many readers. However, there are some issues need to be addressed:

1. The strategy is proposed for fuel cell and batteries in the hybrid boat applications. Please provide more backgrounds on the application of fuel cell and battery systems on the boats. Also, currently, what is the share of HEB in the boats market. 
2. In the real application, boats are operated under different conditions like different loads and speeds. How is the FC-Battery system controlled to satisfy the various operating conditions?
3. Please add a nomenclature table to summarize all the symbols and abbreviations.
4. The manuscript is not well written. Language and grammar issues as well as format errors are everywhere. Please refine the language expression and correct the format errors.
5. Fig.17, the labels are not clear. Please re-label the equipment in the figure.
6. Please enrich and itemize the Conclusion part.

Author Response

Dear Reviewer,

We are very much thankful to the reviewer for this deep and thorough review. We have revised my present research paper in the light of their useful suggestions and comments. We hope my revision has improved the paper to a level of their satisfaction.  Number wise answers to their specific comments/suggestions/queries are as attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Please check again all your equations.

Please check English (grammar and text style)

Author Response

Dear Reviewer,

Thanks again for your time to review our manuscript. 

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors have addressed all the comments. Please add the contents in Response 1 in your coverletter (for reviewer 3) to the Introduction section.

Author Response

Dear Reviewer,

Thanks again for your time to review our manuscript.

Author Response File: Author Response.pdf