Autonomous Decentralized Cooperative Control DC Microgrids Realized by Directly Connecting Batteries to the Baseline

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors claim a novelty on connecting multiple batteries directly on a DC link without the use of DC-DC converters. My decision regarding the manuscript rejection was based on the following points:

1- The introduction is very poor, and there is no comparison with the proposed novelty and others in the literature;

2- There is a lack of experimental results and analysis to support the superiority the proposed method;

3- Some figures are badly presented, for example, Figures 1a and 1b are partially cropped and  Figure 2 is identified with "(b)" twice.

 

 

Author Response

I sincerely appreciate the time and effort you have dedicated to reviewing my manuscript. Please find our responses to your comments in the attached file for your reference.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The study proposes an interesting approach, but does not sufficiently clarify the novelty compared to other similar existing methods. The article presents a promising approach, but suffers from the lack of a rigorous comparison and a well-defined mathematical model. In order to be accepted, the validity of the results must be strengthened and the novelty of the contribution clarified.

In addition, my observations are the following:
1. The authors do not highlight the degree of novelty of the proposed method compared to other existing papers. The authors state that the proposed method is “simple” and “stable”, but without mentioning any limitations or challenges.
2. The introduction mentions several studies, but does not specifically explain how the author’s proposal differs from existing ones.
3. The authors do not present quantitative comparisons between the proposed system and other similar decentralized systems.
4. There are multiple methods for implementing Droop control (e.g., DC/DC converters). The authors do not highlight why the proposed approach is superior. In practice, batteries degrade over time, and their characteristics do not remain constant. The authors should present the long-term impact of this aspect.
5. The authors do not present an analysis of electrical inertia through a concrete mathematical model. Although they mention that inertia improves stability, no simulations are presented to demonstrate the effect.
6. How does weak coupling affect the energy efficiency of the grid?
In the case of the experiment, what happens if a battery fails? How does the system behave under rapid load variations?
7. This section discusses the integration of the proposed solution with the national grid. What are the problems related to the stability of the system?
8. The conclusions are in line with the proposed objectives, but are formulated too optimistically and without mentioning the limitations.

The results obtained are interesting, but require further validation through simulations and comparisons with alternative methods.

Author Response

I sincerely appreciate the time and effort you have dedicated to reviewing my manuscript. Please find our responses to your comments in the attached file for your reference.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The article proposes a method of constructing DC microgrid by connecting “small” batteries distributed to the baseline in order to achieve autonomous decentralized cooperative control through the cooperative operation due to the droop characteristics inherent in the batteries themselves and the control locality due to the weakly-coupled grid configuration. Although the article topic is interesting, the content should be improved in order to be accepted in the Journal. In particular, some points that should be improved are:

 

1.- Introduction Section are poor and incomplete. It needs to be completed with more details about the state-of-the art in the topic. In fact, although the manuscript authors provide a good number of references, more detail about them should be given in Section 1 (Introduction).

2.- Regarding the previous point, what are the advantages of the proposed method? Please, clarify these advantages and, of course, the possible drawbacks of the manuscript proposal comparing to previous implementations.

3.- In fact, notice that in Fig. 3 is not clear what is the capacity of the batteries considered in the study… How does the batteries’ capacity (or even their state-of-charge, SoC) influence on these plots and results? How did you obtain the results showed in this figure?

4.- Regarding this same figure (Fig. 3), please, explain or define in a more accurate way the term “Electrical inertia”.

5.- The methodology explained in Section 4 (Stabilizing grid by electrical inertia) is rather poor and not clear. Notice that more details and analysis should be provided.

6. Considering that the author has a suitable experimental platform, experimental results are poor. It should be improved in order to corroborate the initial hypothesis and theoretical content of the manuscript.

7.- In Section 6 (Demonstration experiment) Please, what is the final energy management system (EMS) of the experimental platform included? Provide the details of this experimental platform. In fact, notice that the plots in Fig. 3 are not validated with the results included in the paper.

8.- Please, complete Conclusion Section including more details about these advantages and disadvantages. In fact, it’s difficult to see these advantages in Section 6 (Demonstration experiments).

9.- regarding point #1, please, complete the manuscript with some other references about the state-of-the art in the topic.

10.- finally, please, correct some figure (Fig. 1 is cut on the right).

 

Author Response

I sincerely appreciate the time and effort you have dedicated to reviewing my manuscript. Please find our responses to your comments in the attached file for your reference.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

What is the maximum value of the power produced in a regional microgrid?

What percentage of the energy consumed in a microgrid is produced by it?

How long can the battery system withstand if production is insignificant?

Improve the references list with more actual papers from literature.

Compare Your results with others from literature.

Author Response

I sincerely appreciate the time and effort you have dedicated to reviewing my manuscript. Please find our responses to your comments in the attached file for your reference.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The changes made by the authors address most of the requests, improving clarity and technical justifications.

However, some aspects, such as quantitative comparisons and simulations, have not been sufficiently addressed.

The conclusions, however, are formulated too optimistically, without mentioning the limitations.

Author Response

Dear Reviewer 2,

Thank you very much for taking the time to review my mamuscript and for your valuable comments.

Your thoughtful review and guidance have been instrumental in improving the quality of my work.

I sincerely appreciate your support throughout this process.

Thank you once again for your efforts and insightful suggestions.

Best regards,

Hirohito YAMADA

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

After reading the new version of the mansucript, in the reviewer's opinion, the article can be considered for publication in the Journal.

 

Author Response

Dear Reviewer 3,

Thank you very much for taking the time to review my mamuscript and for your valuable comments.

Your thoughtful review and guidance have been instrumental in improving the quality of my work.

I sincerely appreciate your support throughout this process.

Thank you once again for your efforts and insightful suggestions.

Best regards,

Hirohito YAMADA

Reviewer 4 Report

Comments and Suggestions for Authors

The modifications made meet the requirements.

Author Response

Dear Reviewer 4,

Thank you very much for taking the time to review my manuscript and for your valuable comments.

Your thoughtful review and guidance have been instrumental in improving the quality of my work. 

I sincerely appreciate your support throughout this process.

Thank you once again for your efforts and insightful suggestions.

Best regards,

Hirohito YAMADA