Utilizing MicroGenetic Algorithm for Optimal Design of Permanent-Magnet-Assisted WFSM for Traction Machines

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. The figure shown in Fig 4(c) is too blurry to read the data in it.

2. The first person is not advised in line 161.

3. The data 8.15% in line 166 can’t be revealed from Fig 5.

4. It is not clear that how the data 5.06% in line 173 is calculated and why it is “modest”.

5. Fig 7 does not indicate the meaning of the vertical axis and the horizontal axis only has data without reference and unit.

6. The terms “target function” in line 244 and “optimization objective function” in line 247 have the same meaning, and "Average Torque=32Nm" should refer to a “equality constraint” instead of a “Target function” in Fig 9.

7. The 4th subgraph on the right of Fig 9 does not indicate the meaning of horizontal and vertical axes.

8. Fig 9 does not indicate under what conditions the optimization process enters the loop and when the process ends.

9. The phrase “experiment points” in line 267 is unclear.

10. The value of the number of training points “nTR” calculated by formula (6) and (7) is 198, which is different from the 80 mentioned above.

11. It is unclear that where the multi-objective optimization mentioned from line 302 to line 308 is applied in this article.

12. The claim that the enhancement in efficiency from 93.99% to 95.07% in line 379-381 of the conclusion is notable is unconvincing, please provide some evidence.

Comments on the Quality of English Language

see my overall comments.

Author Response

Dear Reviewer,

I would like to extend our sincere gratitude for your thorough and insightful review of our paper. Your valuable feedback has been instrumental in enhancing the quality and clarity of our work. We appreciate the time and effort you have dedicated to evaluating our research and providing constructive comments.

1. The figure shown in Fig 4(c) is too blurry to read the data in it.

-> Figure 4(c) has been revised to enhance its clarity to the maximum extent possible.

2. The first person is not advised in line 161.

-> The review comments have been acknowledged and the necessary revisions have been completed.

3. The data 8.15% in line 166 can’t be revealed from Fig 5.

-> The figure has been revised to include the calculated errors for each current, and the accompanying text has been updated accordingly.

4. It is not clear that how the data 5.06% in line 173 is calculated and why it is “modest”.

-> The term "modest" was deemed inappropriate and has been corrected. The paragraph has been revised accordingly to reflect this change.

5. Fig 7 does not indicate the meaning of the vertical axis and the horizontal axis only has data without reference and unit.

-> The figure has been updated to include axis titles.

6. The terms “target function” in line 244 and “optimization objective function” in line 247 have the same meaning, and "Average Torque=32Nm" should refer to a “equality constraint” instead of a “Target function” in Fig 9.

-> Figure 9 has been revised to replace “Target function” with "equality constraint."

7. The 4th subgraph on the right of Fig 9 does not indicate the meaning of horizontal and vertical axes.

-> The figure has been updated to include axis titles.

8. Fig 9 does not indicate under what conditions the optimization process enters the loop and when the process ends.

-> The figure has been updated to include the process loop.

9. The phrase “experiment points” in line 267 is unclear.

-> The wording of "experimental points" has been changed to "training points" to avoid confusion with previous experiments. The equations and paragraphs have been revised accordingly.

10. The value of the number of training points “nTR” calculated by formula (6) and (7) is 198, which is different from the 80 mentioned above.

-> Errors in the equations were identified and corrected. Additionally, references have been added.

11. It is unclear that where the multi-objective optimization mentioned from line 302 to line 308 is applied in this article.

-> The conditions presented in the paper were selected as the objective functions, and an algorithm was performed to satisfy a total of three conditions. Accordingly, the relevant explanation has been added.

12. The claim that the enhancement in efficiency from 93.99% to 95.07% in line 379-381 of the conclusion is notable is unconvincing, please provide some evidence.

->

The following content has been added to the paper:

"When classified according to the International Energy Efficiency class (IE), the existing WFSM falls under the IE3 category, whereas the PMa-WFSM proposed in this paper achieves an IE4 rating."

I have made the necessary revisions to address the reviewer's requests to the best of our ability. We sincerely thank you for your efforts and feedback. Should you have any additional comments or requests for further modifications, please do not hesitate to contact me.

Sincerely,

-Hansoo Seo-

 

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The review report of the paper can be found in the attached file.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,

We would like to extend our sincere gratitude for your thorough and insightful review of our paper. Your valuable feedback has been instrumental in enhancing the quality and clarity of our work. We appreciate the time and effort you have dedicated to evaluating our research and providing constructive comments.

1.The paper shows that the efficiency of the motor proposed by the authors compared to the existing variants increased by 1.08% (From 93.99% efficiency of the existing motors to 95.07% for the motor proposed in the paper). Given the accuracy of calculating the magnetic field using the FEM which is of the same order of magnitude as the increase in efficiency, I believe that it cannot be stated with certainty that the determined efficiency value is real. Additional arguments are required.

-> In this paper, to validate the feasibility and accuracy of the FEM analysis results of the existing motor, a comparison was made with experimental data. The FEM analysis results and experimental data of the WFSM that I previously designed are discussed in Section 2. However, due to equipment issues, there are currently difficulties in conducting additional experiments to measure the motor efficiency.

 

2. Relations 1, 2, 3 in the paper are determined considering simplifying conditions far from reality, which is why they are not suitable for a high precision calculation. The authors must specify in the paper where they used the mentioned relationships, which are far from reality.

->As the reviewer mentioned, accurately calculating the characteristics of the motor using a magnetic equivalent circuit is challenging. Therefore, in this paper, the magnetic equivalent circuit and the related equations were used to verify the trends. The performance calculations for the motor were conducted using FEM analysis. Additionally, references for the equations have been added.

 

3. It is not the unit of measurement of the intensity of the electric current that is effective, but the quantity that characterizes the electric current. As a result, in the work (Table 1, ...) it must be specified that the size represents the effective value and the current is measured in A not in Arms.

->The reviewer's feedback has been incorporated, and the current values have been revised to be represented in amperes unit [A].

 

4. Nothing can be seen from figure 4c, it must be redone, the width of the curve is much too large, compared to figure 4d. The thickness of the curve represents more than 10% of the EMF value. The necessary corrections must be made.

->Figure 4(c) has been revised to enhance its clarity to the maximum extent possible. It should be noted that Figure 4(c) contains experimental data, which includes significant noise. Due to current difficulties in conducting additional experiments, it is challenging to provide new data. A supplementary paper addressing these issues is being prepared, and it will include more accurate data.

 

5. The paper does not specify the cause of the differences between the experimental determinations and those using the FEM. It is necessary to specify how much is the error of the magnetic field calculation method (FEM), respectively the errors of the measurement method.

-> The figures and content related to the error between the experimental values and the FEM analysis results have been revised and updated in the paper.

 

6. In the explanation of figure 8, it is necessary to specify that the lines of the Flux density vector and the modulus of this vector are represented.

->The maximum value of the flux density and the source of the flux lines have been verified and added to the paper.

 

7. The work or works from which the relationships included in the work were taken must be specified.

->References for the equations have been added.

 

8. I did not understand why in figure 11, the barrier angle has the value 6595%. Additional details are required.

->The initial barrier angle was close to 0, which resulted in the figure of 6595%. However, to avoid confusion, this has been revised to indicate that the final barrier angle was to 12 degrees.

 

9. How is it justified that in figure 12 there are very large differences for the torque values and very small for the EMF values obtained by calculation, respectively experimentally?

->The following content has been added to the paper:

"Despite a marginal decrease in torque compared to the baseline, the significant reduction of 5.43% in torque ripple demonstrates enhanced stability and smoother operation of the PMa-WFSM, with the load counter-electromotive force waveform remaining at a similar level, as shown in Fig.12. The average torque remains nearly identical, resulting in the peak and waveform of the EMF being almost the same. However, the torque ripple has significantly decreased due to the increased magnetomotive force (MMF) provided by the permanent magnets."

 

 10. It is necessary to check the technical editing because there are still mistakes (for example 4. COMPARING THE CHARACTERISTICS of WFSM and PMa-WFSM is in capital letters and the other subtitles are in small but bold letters).

->The letters have been uniformly revised to small bold for consistency.

 

11. The paper does not specify how much the cost price of the engine in the proposed version increases compared to that of the existing engines. Additional information is required.

-> Due to the significant price volatility of permanent magnets, it is challenging to provide an exact cost estimate. Therefore, it has been added that the manufacturing costs are expected to increase by approximately 10% compared to existing motors.

 

12. The data presented in Table 4 are conclusive regarding the superiority of the engine variant proposed in the work, compared to the existing engines.

->The content regarding the motor efficiency classifications (IE) has been added:

I have made the necessary revisions to address the reviewer's requests to the best of our ability. We sincerely thank you for your efforts and feedback. Should you have any additional comments or requests for further modifications, please do not hesitate to contact me.

Sincerely,

-Hansoo Seo-

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

All my comments have been addressed. Thanks.