Design Optimization and Electromagnetic Performance Analysis of an Axial-Flux Permanent Magnet Brushless DC Motor with Unequal-Thickness Magnets

Round 1

Reviewer 1 Report

Dear Authors,

The article presented by the authors is relevant for improving the design and performance parameters of the DC motor. The abstract is presented clearly, perhaps a more complete mention of the results is missing, so that the reader is able to get confused with the conducted research while reading the abstract. The keywords are chosen correctly, from them it is clear where the emphasis of this article will be.

The introduction is scattered, many literary sources are mentioned, but their qualitative detailing of who studied what and where is not provided (eg 3-8; 9-16; 17-22). There are incomplete sentences where it is quite difficult to catch up. Scientific innovation should be defined separately by the authors, as it is now combined with other sources and what the authors specifically propose should be highlighted.

If the authors propose structural improvements, they must provide a clear comparison of how their proposal is better than what currently exists.

There are a number of ambiguities in the methodological part, which the authors need to explain in more detail. I would also suggest that you combine chapters 1 and 2 into one and call it the methodology chapter.

The results are the solution of the optimization problem in search of the minimum. But a more detailed analysis of the results is not provided.

The conclusions are not specific and do not fully reflect the obtained results.

More detailed comments are provided in the attached file in the form of text comments.

Comments for author File: Comments.pdf

Author Response

Point 1: The article presented by the authors is relevant for improving the design and performance parameters of the DC motor. The abstract is presented clearly, perhaps a more complete mention of the results is missing, so that the reader is able to get confused with the conducted research while reading the abstract. The keywords are chosen correctly, from them it is clear where the emphasis of this article will be.

Response 1: Thanks very much for reviewer’s good suggestions. In the revised draft, we retwrite the abstract, and give the research significance, methods and results in the abstract. So that readers can clearly know the research content of the paper. The revised part has been marked in the revised version.

Point 2: The introduction is scattered, many literary sources are mentioned, but their qualitative detailing of who studied what and where is not provided (eg 3-8; 9-16; 17-22). There are incomplete sentences where it is quite difficult to catch up. Scientific innovation should be defined separately by the authors, as it is now combined with other sources and what the authors specifically propose should be highlighted.

Response 2: Thanks very much for reviewer’s good suggestions. In the revised draft, we retwrite the introduction according to the suggestions. The revised part has been marked in the revised version.

Point 3: If the authors propose structural improvements, they must provide a clear comparison of how their proposal is better than what currently exists.

There are a number of ambiguities in the methodological part, which the authors need to explain in more detail. I would also suggest that you combine chapters 1 and 2 into one and call it the methodology chapter.The results are the solution of the optimization problem in search of the minimum. But a more detailed analysis of the results is not provided.The conclusions are not specific and do not fully reflect the obtained results.

Response 3: Thanks very much for reviewer’s good suggestions. In the revised draft, we have combed the contents of Chapter 2 and Chapter 3. Optimization is listed in a separate chapter. A detailed optimization method and optimal results are given. Finally, the specific conclusions are rewrited, and the conclusions fully reflect the obtained results.

Thanks very much again.

 

Author Response File: Author Response.docx

Reviewer 2 Report

In this paper is proposed an optimization of a Axial-flux Permanent Magnet Brushless DC Motor 3 with Unequal Thickness Magnets.

The paper is organized on 5 chapter starting with an introduction in the field, followed by Structure of AFPMBLDCM and Main Parameter of it. In chapter 3 is presented the optimization followed by conclusion.

There are the following observations:

1.       The numbering of chapters has to start with 1

2.       The second and third chapter I recommend to be under one chapter. For example, to complete and realize a background chapter followed by nethod.

3.       In the third chapter “Main Parameter Design of AFPMBLDCM” I expected to begin with the parameters not to “No-load back EMF” that is candidate for a previous chapter. Please, reformulate this chapter to be focused only on parameters in a coherent way.

4.       The fourth chapter is a mixt between methodologies, optimizations and results. Please, reformulate the chapter. Please present clearer the improvement given after optimization. Please, develop a discussion about result. Present the results comparative with another works in the actual researching field.

5.       The conclusions are too generals and short.

Author Response

Point 1: The numbering of chapters has to start with 1

Response 1: Thanks very much for reviewer’s good suggestions. We have revised in the revised version.

Point 2: The second and third chapter I recommend to be under one chapter. For example, to complete and realize a background chapter followed by nethod.

Response 2: Please provide your response for Point 2. (in red)

Point 3: In the third chapter “Main Parameter Design of AFPMBLDCM” I expected to begin with the parameters not to “No-load back EMF” that is candidate for a previous chapter. Please, reformulate this chapter to be focused only on parameters in a coherent way.

 Response 3: Thanks very much for reviewer’s good suggestions. In the revised draft, we have combed the contents of Chapter 2 and Chapter 3.

Point 4: T The fourth chapter is a mixt between methodologies, optimizations and results. Please, reformulate the chapter. Please present clearer the improvement given after optimization. Please, develop a discussion about result. Present the results comparative with another works in the actual researching field.

Response 4: Optimization is listed in a separate chapter 4. A detailed optimization method and optimal results are given.

Point 5: The conclusions are too generals and short.

Response 5: The specific conclusions are rewrited, and the conclusions fully reflect the obtained results.

Thanks very much again.

Author Response File: Author Response.docx

Reviewer 3 Report

The work presented is of interest for research in the associated area, however, there are some considerations to take into account:

1.- The process of optimizing torque cogging is not clear. What are the input variables of the optimization model? What are the constraints of the problem? The methodology should be clearer for the reader. Can the authors give more details of the optimization process?

2.- The results shown in Table 3 and Figure 15 do not correspond to each other.

3.- The summary and conclusion should be considerably improved. What the authors show is very superficial

Author Response

Point 1:  The process of optimizing torque cogging is not clear. What are the input variables of the optimization model? What are the constraints of the problem? The methodology should be clearer for the reader. Can the authors give more details of the optimization process?

Response 1: Thanks very much for reviewer’s good suggestions. Optimization is listed in a separate chapter 4. A detailed optimization method and optimal results are given.

Point 2: The results shown in Table 3 and Figure 15 do not correspond to each other.

Response 2: Thanks very much for reviewer’s good suggestions. We have revised in the revised version.

Point 3: The summary and conclusion should be considerably improved. What the authors show is very superficial.

Response 2: Thanks very much for reviewer’s good suggestions. The specific conclusions are rewrited, and the conclusions fully reflect the obtained results.

Thanks very much again.

 

Author Response File: Author Response.docx

Reviewer 4 Report

referee report 

applsci-1814275-peer-review-v1

Design Optimization and Electromagnetic Performance Analysis of an Axial-flux Permanent Magnet Brushless DC Motor 

with Unequal Thickness Magnets

Shasha Wu, Baojian Wang, Quanhao Gu, Tao Zhang

 

The present manuscript proposes an electromotor with a permanent magnet structure with arc magnetic pole of unequal thickness. The authors design an axial-flux permanent magnet brushless DC motor (abbreviated as  AFPMBLDCM).

The topic is very interesting to a broad readership, so it is very well suited for publication in Applied Sciences.

The present manuscript comprises 15 figures, 3 tables and 39 references are given, which provide a good overview on the field. It is obvious that some of the figures could be combined together, which would yield a much better view on all the data collected. 

Overall, the manuscript itself is well written, using proper English, and the figures are well arranged. 

However, when looking the first time at the manuscript, the starting of Section "0" makes a strange impression, which gets even worse as a section "Methods" is completely missing, and so the reader has no idea which techniques were applied to obtain the data presented.

After careful reading the manuscript, there are some more problems as listed here:

# Please take care that abbreviations are properly defined. Too many uncommon abbreviations makes the reading 

quite difficult. Also, abbreviations used in the abstract must be defined in the abstract --> AFPMBLDCM.

# Please take care for spaces in the entire text -- there should be a space between a physical quantity and its unit,

   between text and references, etc.

# It would be very helpful to format all physical quantitites in italics (like when typesetting a formula), not only   in the text and the figure captions, but also in the diagrams.

# As already mentioned, please start with Sec. 1 "Introduction", follwed by a section 2. Methods, where you can (and must)   describe all the details of the simulation methods applied. This will help the readers a lot.

To summarize this review, the present manuscript shows very interesting material, but requires some revision to address the points mentioned above, especially the section numbering and the introduction of a "Methods" section is essential.

Author Response

oint 1: However, when looking the first time at the manuscript, the starting of Section "0" makes a strange impression, which gets even worse as a section "Methods" is completely missing, and so the reader has no idea which techniques were applied to obtain the data presented.

Response 1: Thanks very much for reviewer’s good suggestions. In the revised draft, we retwrite the abstract and introduction. We give the research significance, methods and results in the abstract. So that readers can clearly know the research content of the paper. The revised part has been marked in the revised version.

 

Point 2: Please take care that abbreviations are properly defined. Too many uncommon abbreviations makes the reading quite difficult. Also, abbreviations used in the abstract must be defined in the abstract --> AFPMBLDCM.

 

Response 2: Thanks very much for reviewer’s good suggestions. In the revised draft, we have polished the whole paper.

 

Point 3: Please take care for spaces in the entire text -- there should be a space between a physical quantity and its unit, between text and references, etc. It would be very helpful to format all physical quantitites in italics (like when typesetting a formula), not only in the text and the figure captions, but also in the diagrams.

Response 3: Thanks very much for reviewer’s good suggestions. In the revised draft, we have polished the whole paper.

 

Point 4: As already mentioned, please start with Sec. 1 "Introduction", follwed by a section 2. Methods, where you can (and must)  describe all the details of the simulation methods applied. This will help the readers a lot.

Response 4: Thanks very much for reviewer’s good suggestions.We have adjusted the chapter according to the opinions and described the optimization method in chapter 4 in detail.

Point 5:To summarize this review, the present manuscript shows very interesting material, but requires some revision to address the points mentioned above, especially the section numbering and the introduction of a "Methods" section is essential.

Response 5: Thanks very much for reviewer’s good suggestions.We adjusted the overall structure of the full text, and made detailed modifications and refinements to the full text according to the opinions.

Thanks very much again.

 

 

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Dear Authors many thanks that you revised the paper, but I have a few remarks what you should take to account:

1. Authors use multiple sources of literature to cite a single statement. Such a citation is not appropriate, as each source must be identified as to what exactly it defined when dealing with a specific problem. If the authors want to emphasize that the majority of studies have been carried out on this issue, they must specifically identify it, but on the other hand, the problem itself loses its authenticity, after all, a lot of work has been done on this issue. I suggest that the authors consider whether it is necessary to use both literary sources when defining one statement (e.g. Line 26, Line 30, Line 35, Line 62, Line 64).

2. The authors have wrongly indicated the numbering of the chapters (chapter 3 is repeated twice), I suggest that you carefully review the chapter numbering.

3. Line 239. Why did the authors choose to reduce the cogging torque fluctuation to less than 5%? What exactly led to the 5% limit?

4. The conclusions must be a specific reflection of the main results obtained, Line 279-284 is a description that is not classified as the main results of the study.

Author Response

Response to Reviewer 1

Point 1: Authors use multiple sources of literature to cite a single statement. Such a citation is not appropriate, as each source must be identified as to what exactly it defined when dealing with a specific problem. If the authors want to emphasize that the majority of studies have been carried out on this issue, they must specifically identify it, but on the other hand, the problem itself loses its authenticity, after all, a lot of work has been done on this issue. I suggest that the authors consider whether it is necessary to use both literary sources when defining one statement (e.g. Line 26, Line 30, Line 35, Line 62, Line 64).

Response 1: Thanks very much for reviewer’s good suggestions. We reorganized the references according to the opinions and replaced three references.

Point 2:The authors have wrongly indicated the numbering of the chapters (chapter 3 is repeated twice), I suggest that you carefully review the chapter numbering.

Response 2: Thanks very much for reviewer’s good suggestions. We have revised them in the second revision and marked.

Point 3: Line 239. Why did the authors choose to reduce the cogging torque fluctuation to less than 5%? What exactly led to the 5% limit?

Response 3: Thanks very much for reviewer’s good suggestions. The axial flux motor in this paper is used to drive a new type of electric bicycle. In the early stage, this electric bicycle was driven by axial flux permanent magnet motor with planar permanent magnet, resulting in noise, efficiency and other poor performances. Therefore, we optimized it from four aspects: winding, core, power amplifier and control, and have improved its electromagnetic performances. After the early stage performance test and comprehensive performance evaluation of the motor, we determined the optimization target of 5% in terms of cogging torque optimization. In addition, in the optimization module, we only need to give a reasonable initial optimization goal. In fact, the optimization module will optimize according to the actual situation, not only according to the given optimization goal, and stop optimization after reaching the optimization goal, but will find the optimal parameter combination. Therefore, we give 5% as the optimization target, but the actual optimization result is 2.96%.

Point 4:The conclusions must be a specific reflection of the main results obtained, Line 279-284 is a description that is not classified as the main results of the study.

Response 4: Thanks very much for reviewer’s good suggestions. Referring to the articles published in Applied Sciences, we rearranged the conclusions.

Thank you again for your hard work.

Author Response File: Author Response.docx

Reviewer 3 Report

Thank you very much for making the document more understandable. The reader still has some doubts regarding the optimization process carried out, it is true that there are input variables and restrictions for each of them. However, the optimization process carried out, that is, the mathematics behind the optimization process carried out with the software, is not clear. I refer to this point because the word optimization is present in the title of the document and that is why the reader expected a little more development of this point in the manuscript.

Author Response

Response to Reviewer 2

Point 1:Thank you very much for making the document more understandable. The reader still has some doubts regarding the optimization process carried out, it is true that there are input variables and restrictions for each of them. However, the optimization process carried out, that is, the mathematics behind the optimization process carried out with the software, is not clear. I refer to this point because the word optimization is present in the title of the document and that is why the reader expected a little more development of this point in the manuscript.

Response 1: Thanks very much for reviewer’s good suggestions. Although the parameter optimization is mentioned in this paper, the focus of this paper should be to design the axial flux motor with unequal thickness permanent magnet, and then take the cogging torque as the optimization goal, the pole arc coefficient, the thickness of permanent magnet and the arc radius of permanent magnet as variables to optimize. The optimization method is to use the finite element analysis software Maxwell. Optimetrics module is provided in this software, which determines the optimization objective according to the established model, and solves it according to the determined optimization variables and steps and the designed algorithm in the module. The evaluation of experts has been very valuable. In the future, we will study the optimization algorithm in terms of how to improve the optimization accuracy.

 

Thank you again for your valuable comments.

Author Response File: Author Response.docx