Improved Transient Performance of a DFIG-Based Wind-Power System Using the Combined Control of Active Crowbars

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please check the following sentences:

- “… aiming to protect the DFIG and power converters, and consequently, improve the system’ ability to ride-through faults.”

 

- “This has compelled many power companies to updates their grid codes …”

 

The following sentence seems redundant and repetitive:

- “To enable the WPPs to successfully ride-through grid disturbances, many power companies have updated their grid codes.”

 

Check the following sentence:

- “… a critical analysis of the start-of-the-art techniques …”

 

The following sentence is confusing, please rewrite it:

- “At the DC-link, another crowbar comprises an ESD, a battery in this study, is proposed and inserted in parallel to it.”

 

Language must be revised by a native English speaker to improve grammar and readability.

 

In introduction, from this reviewer point of view, authors failed to describe the novelty and contribution of their work regarding previous approaches in the state-of-the-art in the related subject.

 

In the following sentence, authors should provide at least a reference to support that the assumption they are applying does not affect the analysis.

- “The dynamical behavior of a DFIG under steady-state conditions is investigated using Park’s transformation, and for convenience, all parameters are stated to the stator side.”

 

What is the difference between equations (1a) and (4).

 

Please check the following sentence

- “… efforts are made to establish A direct relation between stator- …”

 

In the following sentence:

- “er is proportional to slip (s), which varies between –0.3 and 0.3.”

 

At least a reference must be provided.

 

The following sentence is redundant.

- “After a grid disturbance, the stator-flux behaviors after a grid fault can be segmented into its …”

 

Authors failed to define variables in equation (12).

 

In the following sentence:

- “… voltage dips unless the psi_sdc does not decay …”

 

Please use the capital-letter psi to improve consistency.

 

Author failed to compare obtained results (the performance of their proposed method) against those in the state of the art of the subject.

 

This work presents an interesting technique for copping with low voltage ride-through ability of the wind-power systems by control schemes based on auxiliary crowbar controls. However, the scientific novelty and contribution of this work regarding previous approaches must be highlighted.

Comments on the Quality of English Language

Language must be revised by a native English speaker to improve grammar and readability.

Author Response

Dear Reviewer,

We thank you very much for evaluating our work and your kind appreciation. We are also sincerely grateful to the reviewer’s positive response to the paper. We have studied all the comments carefully and attempted to implement them accordingly to improve the quality of the manuscript. We hope our responses and revisions are appropriate.

Please see the attached file for detailed point-by-point answers to the reviewers’ concerns.

We would like to thank you for your time and effort taken to review the revised manuscript.

With regards,

Muhammad Arif Sharafat Ali

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have proposed the “Improved Transient Performance of DFIG-Based Wind-Power System Using Combined Control of Active Crowbars. The topic is timely and relevant to the journal's scope, and it is of interest to scholars. The authors should take the following concerns seriously, as they will help to improve the overall quality of the paper.

 

1. Relevance to the scope of Journal:- Yes

2. Originality:- yes

3. Engineering/scientific relevance: Yes

4. Doubtful or controversial arguments:- No

5. Completeness of the reported work:- Yes

6. Adequacy of acknowledgment of the past related work by others, in the reference list:- Yes

7. Length:- Length is justified.

Abstract: Abstract needs to be strengthened.

Introduction/Methodology/Results and discussion:-

1. The first contribution needs to be explained elaborately.
2. Novelty needs to be explained with appropriate flowcharts.

Conclusion: The conclusion shall be improved.

References: Formatting must be improved.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Can be improved

Author Response

Dear Reviewer,

We thank you very much for evaluating our work and your kind appreciation. We are also sincerely grateful to the reviewer’s positive response to the paper. We have studied all the comments carefully and attempted to implement them accordingly to improve the quality of the manuscript. We hope our responses and revisions are appropriate.

Please see the attached file for detailed point-by-point answers to the reviewers’ concerns.

We would like to thank you for your time and effort taken to review the revised manuscript.

With regards,

Muhammad Arif Sharafat Ali

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Author, thanks for the effort in creating the manuscript. The paper presents a solution based on a combination of an energy storage-based crowbar and a rotor-side crowbar that makes the effective transient current and voltage suppression for wind-driven DFIG possible. Generally, this article is interesting. However, there are issues in the presentation of the paper:

- Language editing. The grammatical and technical writing can be improved. Please revise and check the whole text.
- Abstract.  Explain a little more about the results in the abstract and how the proposed approach is effective. The abstract should be independent and concise so that readers can, to a certain limit, understand what is given in the article.

- Line 168. – Why do the slip (s) vary between –0.3 and 0.3? Explain more this aspect.
- Line 169. – Why the most serious scenario of a maximum voltage dip is considered at (d = 1) and s = –0.3?
- Section 6.2. Has the performance of the proposed control scheme been tested for another Asymmetrical Grid Fault, i.e. for a line-to-line or double line to the ground? Explain this aspect please in the text.
- Section 6.2. Include a discussion paragraph about how the outcomes demonstrate the superior performance of the designed approach in alleviating the DC-link overvoltages, confirming that can be a viable solution.
 - Conclusions. Derived conclusions are not given well. I suggest to rewrite this part.
- Include a little bit about what could be the future direction of your research.

    Comments on the Quality of English Language

The grammatical and technical writing can be improved. Please revise and check the whole text.

Author Response

Dear Reviewer,

We thank you very much for evaluating our work and your kind appreciation. We are also sincerely grateful to the reviewer’s positive response to the paper. We have studied all the comments carefully and attempted to implement them accordingly to improve the quality of the manuscript. We hope our responses and revisions are appropriate.

Please see the attached file for detailed point-by-point answers to the reviewers’ concerns.

We would like to thank you for your time and effort taken to review the revised manuscript.

With regards,

Muhammad Arif Sharafat Ali

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Authors have addressed all my recommendations and comments satisfactorily.

Reviewer 3 Report

Comments and Suggestions for Authors

Thanks for your work.