Design and Optimization of a High-Frequency Oscillation Suppression Strategy for the Grid-Connected Inverter of a Permanent Magnet Direct Drive Wind Turbine

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. Please carefully review the entire manuscript to enhance the overall writing quality, ensuring clarity, coherence, and grammatical accuracy for improved readability and comprehension.
2. The identified weaknesses in references [6–13] are acknowledged; however, they are not sufficiently addressed within this paper. Furthermore, the review of references [14–20] does not contribute meaningfully to the development of the proposed method. Only references [25–26] appear to be directly relevant and beneficial to the study. It is recommended to incorporate additional relevant references to strengthen the theoretical foundation of the study. Additionally, the introduction section should be revised to clarify the research question and explicitly highlight the study's contribution to the field.
3. Please ensure that the parameters are introduced with precise definitions, aligning them consistently with the variables labeled in Figure 2.
4. Could you provide references to support the recommendation of ωc as 0.3 ωr?
5. The distinction between Kp and Hi requires further clarification. Specifically, if proportional-integral (PI) control is not depicted in Fig. 11, it is unclear why the Kp parameter is utilized in the grid-connected inverter, as presented in Table 1. Additionally, a more detailed explanation of the roles and functions of Hi and Hv is necessary to enhance the clarity of their contributions to the system.
6. Could you clarify the location of Figure 24 (p. 16, r. 408) as it is not currently present in the manuscript? Additionally, please provide a more detailed explanation of the methods or procedures used to obtain Figures 18 and 19 to enhance clarity and reproducibility.
7. Consider revising the justification for selecting fs/3 as the boundary frequency. The current explanation does not clearly establish why this specific value is appropriate. Additionally, the suppressed frequency range does not correspond to what is typically referred to as high frequency. It is recommended to conduct further analysis to assess the impact on high-frequency oscillations.
8. Please clearly articulate the contributions of the paper and ensure that the conclusion explicitly addresses the problems discussed in the Introduction section.
9. Please incorporate more recent references into the manuscript and revise the introduction section accordingly to reflect these updates

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Since some formulas cannot be written in the reply column, my reply to the review comments is completely replied to your review comments in the PDF uploaded in the attachment. Thank you for your criticism of the issues related to my thesis.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript focuses on the study of hybrid control strategies aimed at reducing harmonic production in inverters utilized in wind generators. The authors provide a comprehensive and up-to-date literature review pertinent to the topic. Furthermore, they propose a theoretical approach that incorporates an extensive mathematical framework derived from control theory and validates their findings through simulation.

While the authors have made commendable efforts, there are significant issues in the writing that hinder the overall understanding of the text (e.g: paragraph spanning lines 160 to 166). I recommend a thorough revision and adjustment of the manuscript in this regard.

Additionally, many acronyms are not defined throughout the text (e.g., CCF, PCC, Ad, etc.). Including a glossary would greatly enhance clarity for the reader.

Regarding Table I, the expression “Filter Inductance C/uF” appears to be incorrect.

In line 360, it is inappropriate to refer to "experimental results" when no experiments have been conducted; only simulations have been performed. Conducting experimental validation of the authors' proposals would significantly enhance the study.

For Figure 15, the font size used for labeling on the axes is too small.

Lastly, in line 366, I believe that what is being referred to is a Bode plot.

Author Response

Since some formulas cannot be written in the reply column, my reply to the review comments is completely replied to your review comments in the PDF uploaded in the attachment. Thank you for your criticism of the issues related to my thesis.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents an interesting evaluation of the negative effect of oscillatory suppression strategy, with a proposal of a control strategy based on the active damping superposition. However, the manuscript is confusing in several aspects.

The title of the manuscript seems confusing and very long to me. I'd suggest to reduce it and to make it more concise. As it is written, it can be hard to attract the attention of the readers. The abstract is confusing too. The authors present a detailed description of the scheme evaluated in the abstract, and this is not necessary - it is also making it more confusing. Please revise it. And the keyword "new power system" is also generic and could be updated.

The introduction section should contribute to the comprehension of the problem, however it is dedicated to a literature review. Please reorganize the text. Also, all the text in page 2 is in a single paragraph; please split the text in more paragraphs or it will be very confusing to understand it. And is it very common to present a short paragraph, in the end of the introduction section, listing how the rest of the manuscript is organized. Please verify the templates and rewrite the introduction.

10 of the 26 references cited are recent (published since 2020). It is then recommended to add more recent references to the manuscript. Also, there aren't references from MDPI journals, and there are several relevant publications from MDPI journals that could be cited.

Some figures are not in a good resolution. Please verify the quality of all the figures in the manuscript (specially with the figures 1, 2, 7 to 14). Also, remember that the caption of the figure must be in the same page that the figure is presented (please observe the figures 2 and 17).

The description of the results in section 4 should be revised and improved. Figures 15 to 19 should be better detailed and explained.

The conclusion section is very simplified and must be rewritten and improved. It is also missing the next steps of the research.

Comments on the Quality of English Language

There are several typos in the manuscript that should be fixed to provide a better comprehension to the readers.

Author Response

Since some formulas cannot be written in the reply column, my reply to the review comments is completely replied to your review comments in the PDF uploaded in the attachment. Thank you for your criticism of the issues related to my thesis.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Well addressed. There are no further questions; however, one question remains:

1. Could you please clarify the change in results shown in Fig. 17(b)? Kindly ensure that the data used in this version is the same as in the previous one.

Thank you.

 

Comments on the Quality of English Language

Looks good now, but can still be improved.

Author Response

Comments1：Could you please clarify the change in results shown in Fig. 17(b)? Kindly ensure that the data used in this version is the same as in the previous one.

Response1:Thank you for your question. The change in Figure 17(b) merely involves expanding the coordinate reference of the FFT analysis to 2000 Hz. Compared to the original 1000 Hz, this adjustment is more in line with the actual resonant frequency. The other parameters remain unchanged.

Once again, we deeply appreciate your guidance and the opportunity to improve our manuscript.

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript has been significantly improved.

Although figures can be enlarged in digital format, authors are advised to consider possibly having the manuscript read in print. I leave this matter to the authors' discretion.

I would recommend its publication.

Author Response

Thank you for your suggestions. In the process of revising the overall format of the subsequent paper, I will make the pictures and the paper text adapt to each other as a whole to facilitate reading.

Once again, we deeply appreciate your guidance and the opportunity to improve our manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

I would like to congratulate the authors for the revised version submitted. All the issues identified in the initial version were properly adressed by the authors, and also commented in the reply letter. The manuscript was significantly improved and new and relevant references were added to the manuscript. In this way, I do not have further recommendations for the authors.

Author Response

We are very grateful again for your guidance