Experimental and Numerical Analysis of the Effect of a New Lightning Protection System on Lightning Protection and Aerodynamic Noise Performance of Wind Turbine Blades

Round 1

Reviewer 1 Report

In the paper, a lightning protection system based on the mechanism of lightning was presented. A high voltage discharge test and electrostatic field calculation for the lightning protection system were carried out, and the effect of this system on the lightning protection efficiency of blades was analysed. The obtained results are interesting and encouraging. However, the authors should consider the following aspects to improve the structure and quality of paper:
1. A list with abbreviations and notations should be introduced.
2. In the first part of paper, the authors present various approaches from literature. I think that a synthesis of the solutions proposed in literature depending of the type of analysis, which to highlight more clear the advantages and disadvantages, is useful for readers. This synthesis can be given as a table.
3. The reference loops must be removed and given brief details about each reference (for example, [2] - [5], [10]-[16], [17]-[25] …).
4. In paragraph 2, the presentation of the numerical method is not adequate, with a lack of mathematical rigor. Also, the authors refer to another paper "For a detailed introduction to the calculation method, please refer to the previous papers [49] published by our team". This part must be improved and maybe an annex should be introduced.
5. The measurement unit for each variable should be indicated when this is presented in the paper.
6. Some figures are unclear (fig. 12, fig. 15). The authors should ensure a better quality.
7. The authors should illustrate a bit better the practical and economic benefits of employing such an approach in the final conclusions.

Author Response

Q: First of all, thank you very much for your suggestions and opinions. Your suggestions are very helpful to improve the structure and quality of this paper. Secondly, your suggestion is very useful. I agree with your suggestion very much. I have revised the paper point-to-point according to your suggestion.. Thank you again for your suggestion.

In the paper, a lightning protection system based on the mechanism of lightning was presented. A high voltage discharge test and electrostatic field calculation for the lightning protection system were carried out, and the effect of this system on the lightning protection efficiency of blades was analysed. The obtained results are interesting and encouraging. However, the authors should consider the following aspects to improve the structure and quality of paper:

1. A list with abbreviations and notations should be introduced.

Q: Thank you very much for your question. I think it's very necessary, but it doesn't seem to fit in with the style of the journal. But I've made abbreviations and notations very clear in this article.

2. In the first part of paper, the authors present various approaches from literature. I think that a synthesis of the solutions proposed in literature depending of the type of analysis, which to highlight more clear the advantages and disadvantages, is useful for readers. This synthesis can be given as a table.

Q: Thank you very much for your suggestion. This is a very good suggestion. I have made some modifications in this article.

3.The reference loops must be removed and given brief details about each reference (for example, [2] - [5], [10]-[16], [17]-[25] …).

Q: Thank you very much for your question. This suggestion is necessary to improve the quality of the paper. It has been modified.

4.In paragraph 2, the presentation of the numerical method is not adequate, with a lack of mathematical rigor. Also, the authors refer to another paper "For a detailed introduction to the calculation method, please refer to the previous papers [49] published by our team". This part must be improved and maybe an annex should be introduced.

Q: Thank you very much for your suggestion. In the paragraph 2, the numerical method is not precise enough for a scientific paper. I have supplemented the relevant numerical method.

5.The measurement unit for each variable should be indicated when this is presented in the paper.

Q: Thank you very much for your suggestion. I have added measurement units for each variable in this article

6.Some figures are unclear (fig. 12, fig. 15). The authors should ensure a better quality.

Q: Thank you very much for your suggestion. These figures have been modified.

7.The authors should illustrate a bit better the practical and economic benefits of employing such an approach in the final conclusions.

Q: Thank you very much for your suggestion. It's a very good suggestion. I have made some comments in the conclusion section.

Reviewer 2 Report

In this paper the authors propose a new type of lightning protection system for wind turbine blades. It is a well written paper and it is interesting that the authors carried out experiments. However some points should be mentioned and should be included within the manuscript in order to improve the publication.

In section 2.1 the authors should describe in more detail the arrangement of the new lightning protection system. In line 211 the authors refer that a negative standard lightning impulse voltage is applied to the blade. The results in case of a positive standard lightning impulse voltage could be investigated. The position of the rod electrode could be moved in parallel with the blade and ten discharges applied to the blade in each position. In section 2.2 the authors should describe in more detail the finite element model. The authors should refer the finite element software and the solver. In addition the authors have to refer the assumptions of the numerical simulations.

Author Response

Q: First of all, thank you very much for your suggestions and opinions. Your suggestions are very helpful to improve the structure and quality of this paper. Secondly, your suggestion is very useful. I agree with your suggestion very much. I have revised the paper point-to-point according to your suggestion.. Thank you again for your suggestion.

In this paper the authors propose a new type of lightning protection system for wind turbine blades. It is a well written paper and it is interesting that the authors carried out experiments. However some points should be mentioned and should be included within the manuscript in order to improve the publication.

In section 2.1 the authors should describe in more detail the arrangement of the new lightning protection system.

Q: Thank you very much for your suggestion. I have added a more detailed arrangement of this section to the article.

In line 211 the authors refer that a negative standard lightning impulse voltage is applied to the blade. The results in case of a positive standard lightning impulse voltage could be investigated. The position of the rod electrode could be moved in parallel with the blade and ten discharges applied to the blade in each position. In section 2.2 the authors should describe in more detail the finite element model. The authors should refer the finite element software and the solver. In addition the authors have to refer the assumptions of the numerical simulations.

Q: Thank you very much for your suggestion. This is a very good suggestion. I have added the derivation process of the finite element model in Section 2.2,and the  assumptions of numerical simulation is also consulted.

Round 2

Reviewer 1 Report

I can say that the authors performed changes the initial manuscript. New explanations and elaborations of details were brought. In this form, the revised paper can be accepted.

Author Response

Dear reviewer

Thank you very much for your review. It is your comments and suggestions that make this paper more rigorous. Your suggestions are very helpful to improve the structure and quality of this paper.

 

Kind regards,

 

Xinkai Li

Reviewer 2 Report

The revised version of the paper "Experimental and Numerical Analysis of the Effect of a New Lightning Protection System on Lightning Protection and Aerodynamic Noise Performance of Wind Turbine Blades" has been improved with respect to its original version. The authors should comment two points:

In line 211 the authors refer that a negative standard lightning impulse voltage is applied to the blade. The results in case of a positive standard lightning impulse voltage could be investigated. The position of the rod electrode could be moved in parallel with the blade and ten discharges applied to the blade in each position.

Author Response

Q: Thank you very much for your review again. I'm very sorry. I didn't understand your meaning in the first review. Now I understand. Thank you very much for your comments.

In line 211 the authors refer that a negative standard lightning impulse voltage is applied to the blade. The results in case of a positive standard lightning impulse voltage could be investigated.

Q: Thank you for your comments. All the experiments were carried out under negative standard lightning voltage. There are some mistakes in the article. I have realized that and corrected them in the article.

The position of the rod electrode could be moved in parallel with the blade and ten discharges applied to the blade in each position.

Q: Thank you for your comments. Yes, the rod electrode could be moved in parallel with the blade for the convenience of arranging the experiments, because we have other experimental schemes. So we placed the rod electrode in two positions, corresponding to the blades with or without NLPS, and conducted ten discharge experiments for each scheme, which did not affect our experimental conclusion. Thank you very much for your questions. I added the necessary explanations in this article.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.