An Optimal Operation Strategy for Surge Protective Devices in Li-Ion Based Energy Storage Systems

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this study, authors proposed an optimal operation strategy for surge protection device in energy storage system. They proposed one method and validate through the case studies. However, the organization and presentation of the paper is poor. The scientific contribution is not clear. A method is proposed but why and how this method or steps are determined is not explained. With this existing format, the paper looks like a technical report. Some other comments are also given below:

 

• What do SD and MCB stand for? There are many abbreviations that are not given in their original form.
• Abstract should be rewritten. It should explain the aim of the paper, the used method and obtained achievements.
• Literature review is missing. Introduction should be extended with state-of-the-art solutions, their limitations, and main problems or limitations that aimed to be solved with this paper.
• The last paragraph of the paper is almost the same as the abstract!
• What are the primary subsystem, control subsystem and auxiliary subsystem (when Fig. 3 is considered)?
• Results section should be supported with comparisons.

Author Response

Thank you for your careful review of the paper. The answers to comments are as follows.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript addresses a highly relevant topic, as surge protection for Li-ion energy storage systems is essential for ensuring safety and reliability in renewable energy applications. It is well structured, guiding the reader logically from the introduction through methodology, case studies, conclusions, while presenting the optimal SPD operation procedure in a clear step-by-step manner. A major strength lies in the inclusion of experimental validation, where both 1-port and 2-port SPD configurations are tested and compared, lending credibility to the proposed approach. Furthermore, the work is grounded in international standards such as IEC and IEEE, which enhances its technical rigor and practical applicability for real-world deployment.

Few observations for the authors, in order to improve the readiness of the article:

1. Abstract must be rewritten, as it is repetitive and misstructured.
2. The Introduction must be extended with 1-2 paragraphs, to state clear positioning of this manuscript in relation to previous studies.
3. Paragraph from lines 75-77 is very convoluted and the parameters are abstract (must be justified). Also, the margin ratio and weighting factors have to be justified or referenced.
4. Figure 7 is unreadable.
5. The surge reduction rates (48.2%, 96.2%) are promising, but authors have to provide measurement uncertainties.
6. Discussion section is necessary, to state: comparison with other SPD design strategies in literature, limitations of the study, implications for real ESS in terms of costs and/or reliability.
7. References must be broaden, to include more international studies beyond IEC/IEEE standards.

Author Response

Thank you for your careful review of the paper. The answers to comments are as follows.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Many thanks to the authors for preparing the manuscript!
I have a few comments and notes for correction. Please refer to your PDF document with my comments (electronics-3822363-peer-review-v1_mr.pdf)!

Comments for author File: Comments.pdf

Author Response

Thank you for your careful review of the paper. The answers to comments are as follows.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thanks for revisions.

Author Response

Thank you for your review.

Reviewer 2 Report

Comments and Suggestions for Authors

In the revised version of the manuscript, authors have addressed most of the observations and the paper in entirely is enhanced.

Regarding my comments, some aspects still need to be resolved:

Comm.5 - Figure 7 is still unreadable.

Comm.6 - Measurement uncertainties refer at least to coefficient of variation calculation  (see this reference https://users.physics.unc.edu/~deardorf/uncertainty/UNCguide.pdf)

Adding "around" to the value is not relevant, better remove.

If authors intend to expand this study in future work, this issue must be addressed: 1. State the model and contributors (probe, scope, bandwidth, sampling/peak, generator setting, repeatability).   2. Provide a compact table per representative case (e.g. 1-port Case II and 2-port Case V).  3.Report expanded uncertainties with k=2 and explicitly note that sampling time = 10 μs is the dominant term for peak detection in μs-front waveforms.   4.For compliance claims (“kept within 1.5 kV”), compare Vres​+U to 1.5 kV; if Vres+U<1.5 kV you can state conformance with 95% confidence. Otherwise, state the measured margin and uncertainty transparently.

Practical takeaway: either (a) acquire at a much finer sampling interval (10× faster than the 1.2 μs front, e.g., ≤100 ns/sample) or (b) base the measurand on a time-averaged or RMS quantity aligned with the sampling, or (c) characterize the peak with a peak-hold or analog envelope measurement whose bandwidth matches the surge. Otherwise the uncertainty budget will be dominated by peak-picking error.

Comm. 7 - The suggestion was to create the Discussion section, where to effectively discuss the particularity of this method, limitations of the study, implications for real ESS in terms of costs and/or reliability. Authors merged this suggestion with Comm.2, which is not right.

Author Response

Thank you for your review of the paper. the answers to comment are as follows.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

Good luck with the paper!