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by
  • Jiale Guo 1,
  • Rongsheng Han 1,2 and
  • Long Zhang 3
  • et al.

Reviewer 1: Anonymous Reviewer 2: Ziheng Xiao Reviewer 3: Anonymous

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article entitled “Research on Frequency Characteristic Fitting of LLC Switching mode Power Supply Under All Operating Conditions Based on FT-WOA-MLP” has been reviewed and the comments are as follows.
1.    The methodology followed in the proposed work is well stated in the abstract. However, the reason for developing such MLP based model is not justified anywhere.
2.    Similarly, the integration of MLP with WOA is expected to be explained clearly with mathematical and theoretical descriptions.
3.    Discuss about the tunning parameters included in the work for optimization. Present on what basis such tuning is done.
4.    Expand LLC once in the article and mention how the AC excitation signal is used for a feedback to an DC switching circuit.
5.    What is the role of error amplifier and compensation circuit? If the signal is compensated why there is a PWM controller?
6.    Include a table to represent the list of information that are used for MLP for its training process.
7.    Explore the steps involved in the work on random generation of whale positions.
8.    Mention how the algorithm identifies that the WOA tried with the maximum iterations.
9.    More clarity is expected on the new specific task layer included in the work on constructing the FT model.
10.    Update the experimental section by mentioning the list of simulation and software tools used in the work for analysis.
11.    Conclude the paper by mentioning the reason for comparing the work with MLP and its combinations alone. Why it is not compared with any existing standard works.

Author Response

Kindly see the attached document.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This paper presents a frequency characteristic fitting method for LLC resonant converters across all operating conditions, based on FT-WOA-MLP. While the proposed approach is conceptually promising, several technical and clarity-related issues should be addressed to improve the overall quality of the manuscript:

  • Research on the operation modes of LLC resonant converters has already been addressed in prior studies—for example, works that neglect parasitic components [e.g., X. Fang, H. Hu, Z. J. Shen and I. Batarseh, "Operation Mode Analysis and Peak Gain Approximation of the LLC Resonant Converter," in IEEE Transactions on Power Electronics, vol. 27, no. 4, pp. 1985-1995, April 2012.] and others that account for parasitic components and deadtime [e.g., Z. Xiao, Z. He, R. Guan and A. Luo, "Piecewise-Approximated Time Domain Analysis of LLC Resonant Converter Considering Parasitic Capacitors and Deadtime," in IEEE Transactions on Power Electronics, vol. 38, no. 1, pp. 578-592, Jan. 2023.]. From this perspective, what is the main contribution of this paper beyond existing literature?
  • No analytical derivation of the LLC resonant converter is provided. A small-signal model can also be derived using the fundamental harmonic approximation method, and the absence of this analysis weakens the technical foundation of the work.
  • If the proposed method is data-driven, the manuscript should clearly state whether the training data is obtained from simulations or experiments.
  • If the model is trained on simulation data, what errors arise when compared with experimental results? If trained on experimental data, how can the model be transferred from one converter to another without a time-consuming data acquisition process?
  • The parameters of the experimental prototype should be provided in detail to ensure reproducibility and to support the validity of the results.
  • The paper should include a case example to demonstrate how the proposed model can be applied in practice.
  • A comprehensive comparison between the proposed method and conventional analytical models should be presented to highlight the advantages and limitations of the approach.

Author Response

Kindly see the attached document.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The reviewed article is interesting and it contains valuable results of investigations. My subject of this article is fitting of frequency characteristics of quasi-resonant SMPS. In my opinion this article is worth publishing, but before final acceptance it needs a revision. In the revised version of this article the Authors should take into account the following remarks:

  1. The detailed diagram and values of all the components of the tested SMPS should be included.
  2. The diagram of the experimental set-up should be given.
  3. Why such narrow frequency range (from 10 Hz to 10 kHz) is considered? It should be justified that higher frequency values are not important.
  4. The presented frequency characteristics should be defined. Adequate formulas should be added.
  5. The section Conclusion should be extended. All the advantages and limitations of the proposed method should be pointed out.
  6. How the obtained results can be used in the computer analyses of quasi-resonant SMPS? 
  7. It should be explained, why the method of average modelling of SMPS should be improved. 
  8. Some characteristics of the considered SMPS operating with closed feedback loop should be added and commented.

 

Author Response

Kindly see the attached document.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have carried out all suitable corrections suggested by me and they have improved the paper well. Hence the paper shall be accepted in present form.

Author Response

We sincerely thank you for the very positive evaluation and for recommending acceptance of our work. We are grateful for the constructive comments that helped us improve the manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

Most of comments are well-addressed.

The length of the paper is too long. Consider removing figures with similar meaning.

Author Response

Comment: The length of the paper is too long. Consider removing figures with similar meaning.

Response: We sincerely thank the reviewer for this valuable suggestion. In the revised version, we have streamlined the figures to reduce redundancy while retaining all key evidence. Specifically:

  • The original Figs. 11–13 (amplitude-frequency under multiple conditions) and Figs. 17–19 (phase-frequency under multiple conditions) have been condensed into one representative figure each (new Fig. 11 for amplitude and new Fig. 15 for phase), showing three key operating points: 380 V / 18 A (minimum), 530 V / 54 A (rated), and 710 V / 72 A (maximum).

  • The complete set of operating combinations (all voltages and current levels) has been moved to the Supplementary Information (Figs. S1–S6), where readers can still access the full comparisons.

Reviewer 3 Report

Comments and Suggestions for Authors

The Authors properly addressed all my remarks.

Author Response

We sincerely thank you for the very positive evaluation and for recommending acceptance of our work. We are grateful for the constructive comments that helped us improve the manuscript.