The Study of the Salient Pole Geometry Optimization of the Flux Switching Permanent Magnet Machine

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

My comments below:

1. In terms of editing, the work is prepared very untidy, which makes it difficult to review.

2. Figures, equations and tables escape outside the text column. Inconsistently signed drawings, sometimes ending with a dot.

3. Please explain why the "motor" is in some cases written in lower case at other times in upper case.

4. The authors state that "the average torque has been obviously promoted, and the torque ripple has also decreased" and after a while they add that "But the torque ripple still has a little magnitude. There is still room for motor optimization" [lines 221-224, Fig. 7] - In my opinion, the optimisation applied has failed.

Noting as above, I conclude that the article does not add value to the issues of torque ripple optimisation. In addition, it has been drafted very carelessly and I therefore do not recommend its publication without major revisions.

Author Response

Dear Reviewer:

We deeply appreciate the time and effort you’ve spent in reviewing on our manuscript ‘The study of the salient pole geometry optimization of the flux switching permanent magnet machine ‘(ID: actuators-3184090). Your comments are really thoughtful and helpful. According to the comments and suggestions, we carefully revised the manuscript.

1. In terms of editing, the work is prepared very untidy, which makes it difficult to review.

Response: We deeply apologize for the trouble caused to your review. We have revised the manuscript in detail referring to the template of the journal and hope that the revised manuscript can meet your requirements.

 

 

2. Figures, equations and tables escape outside the text column. Inconsistently signed drawings, sometimes ending with a dot.

Response: Thanks for your advice and the corresponding contents are revised in manuscript. I apologize for the misunderstanding of the journal template in the earlier stage.

 

3. Please explain why the "motor" is in some cases written in lower case at other times in upper case.

Response: Thanks for your question. The lower case and upper case of “motor” are all checked and modified in the manuscript referring to the template of the journal.

 

4. The authors state that "the average torque has been obviously promoted, and the torque ripple has also decreased" and after a while they add that "But the torque ripple still has a little magnitude. There is still room for motor optimization" [lines 221-224, Fig. 7] - In my opinion, the optimisation applied has failed.

Response: Thanks for your question. The whole optimization process is divided into two sections. In the first section, the ripple of torque is optimized from 4.080Nm to 11.473*0.638*0.1=0.732Nm. In the second part, the shape of rotor salient pole is optimized and the torque ripple decreases from 0.732Nm to 0.349Nm. The words "But the torque ripple still has a little magnitude. There is still room for motor optimization" [lines 221-224, Fig. 7] appears between the first and second optimization part. And it is a connection of two parts. Perhaps this description is not appropriate, so we have revised this sentence as follows: “The previous optimization basically determined the effect of the main magnetic circuit on the motor performance. However, other parts in the magnetic circuit still have effects on the motor performance.” The modifications are added in the manuscript.

 

5. Noting as above, I conclude that the article does not add value to the issues of torque ripple optimisation. In addition, it has been drafted very carelessly and I therefore do not recommend its publication without major revisions.

Response: Thank you for the valuable suggestions and question. We will make detailed revisions to the full manuscript to meet your requirements as far as possible. The changes are highlighted in red on the revised manuscript. Finally, thank you again for your review.

Reviewer 2 Report

Comments and Suggestions for Authors

Interesting and well written paper with impressive results.

Differences between experimental and simulation results are explainable and depends on the model level of detail.

 

Please specify the current value for which the motor torque ripple peak-to-peak are shown in Figure 3 (b), 4(b), 5(b), 9(b) and 10(b)

 

 

Comments on the Quality of English Language

Lines 36-37: The FSPM motor as Figure 1 shows, a stator permanent magnet motor which its magnet installs in stator … should be rephrase!

Line 91: the most significant effort... should be rephrase!

Other similar expressions should be rephrase or corrected.

Conclusions should be detailed and presented at the end of the paper!

Author Response

Dear Reviewer:

We deeply appreciate the time and effort you’ve spent in reviewing on our manuscript ‘The study of the salient pole geometry optimization of the flux switching permanent magnet machine ‘(ID: actuators-3184090). Your comments are really thoughtful and helpful. According to the comments and suggestions, we carefully revised the manuscript.

1. Please specify the current value for which the motor torque ripple peak-to-peak are shown in Figure 3 (b), 4(b), 5(b), 9(b) and 10(b)

Response: Thanks for your suggestion. Based on the constant q-axis current excitation, the current magnitude has little effects on the peak-to-peak values of torque ripple. So that, the only the 0A current excitation result are used to demonstrate the torque ripple feature is appropriate. The supplementary statements are added in the manuscript.

 

2. Lines 36-37: The FSPM motor as Figure 1 shows, a stator permanent magnet motor which its magnet installs in stator … should be rephrase!

Response: Thanks for your advice. The sentence is rephrased as “Figure 1 shows the FSPM motor configuration. Its permanent magnets install in stator.” The modification is marked in red in the revised manuscript.

 

3. Line 91: the most significant effort... should be rephrase!

Response: Thanks for your advice. The words are rephased as “the most significant effect”. The modification is marked in red in the revised manuscript.

 

4. Other similar expressions should be rephrase or corrected.

Response: According to your advice. The expressions in the manuscript are checked are corrected. The modification is marked in red in the revised manuscript.

 

5. Conclusions should be detailed and presented at the end of the paper!

Response: According to your advice. The conclusion was rewritten and the modification is marked in red in the revised manuscript.

Reviewer 3 Report

Comments and Suggestions for Authors

The paper entitled "The study of the salient pole geometry optimization of the flux switching permanent magnet machine” focuses on rotor optimization for a 10-rotor/12-stator pole (PM) reluctance machine, resulting (based on Figure 7) not only in reduced torque ripple but also in increase of its average value. The article has the advantage of a prototype, but related tests and calculation comparisons are presented in a limited form. The fact that it is a rather large electric machine (Fig. 11), where the rotor and stator diameters are 99 and 202 mm with stack length of 67 mm, respectively, but the load current and load torque are small, 0.9 A and 5 Nm, respectively (Fig. 14), gives a vague idea of the goals and necessity of the research. Are there some challenges related to the winding design? High number of turns that results thermal limits?

The general assessment is that it is an interesting work that would allow a more in-depth look at the analysis and characteristics of the FSPM machine, especially since the work includes both FEM analysis and prototype tests. A general recommendation is that both the abstract and the introduction of the article should provide a better overview of the work done as well as an overview of the performance and effectiveness of FSPM machines.    

Abstract: In this scientific work, if there is an experience that deserves to be presented as a publication, from which other engineers and developers dedicated to electrical machine design can learn and follow, then what is it? Does The abstract of the article summarize adequately the work done? Does FSPM have high power density – compare and verify. “suitable for power sources (line 10)” – what is the dedicated application (area), machine tools (lines 25, 41)? “With this model (line 15)” – what model? Curve fitting based on FEM data of parameter study? “multi-objective numerical optimization” – what are the objectives and what is actually achieved? “improve the motor performance is feasible and efficient” – the authors are kindly obliged to provide the performance and efficiency values of the studied FSPM and compare them with other FSPM and PM machines.

Intro: What is the purpose of this paper regarding the status of FSPM machines? Since rotor cooling is no longer a problem (no magnets or windings), according to the introduction, choosing FSPM, as the electrical machine topology eliminates the problem of high current, heat load, and according to the introduction, only the torque pulsation becomes a challenge – investigate, recommend, choose a counterpart topology for the same application, like a surface mounted permanent magnet synchronous machine (SPMSM) and compare on equal terms for aforementioned machine tools applications (line 25, 41). An electrical machine should as a primary criterion to provide accelerating or decelerating torque for its application, depending on if it is in motoring or generating mode, at the non-over dimensioned size, is this condition somehow addresses in this machine topology study? address the torque and power density, and compare. How the machine presented in this article compares to other FSPM machines [4]-[16] in terms of torque, power density and torque ripple?

The conclusion should reflect the learning outcomes and the results of the study on the research question(s) and what was achieved as performance improvements rather than a summary of what was done

Some remarks and suggestions, alternatively authors should explain or improve the expressions:

1.      Fig 2. Table 1. And so on: Bpm, Bst, Brt – capital B is conventionally used for flux density respectively in permanent magnets, rotor and stator teeth (according to indexes). The recommendation is to use a small letter b for the breath or width of geometry

2.      Why are the dimensions of the poles and magnets given in degrees (table 1) when the drawing (Fig 1) shows the corresponding details of the machine's construction with parallel sides? If angle measurements are necessary, it must be noted at which radius they are specified

3.      Line 87, show that the flux is sinusoidal and not trapezoidal. Can induced voltage waveforms be shown and verified in the measurement section?

4.      Line 87, what is magneto resistance, is it reluctance?

5.      Line 89, what is “the stability of torque output”, what affects it and how? Best if torque pulsation is shown as a function of rotor position when using constant torque (current) control.

6.      “significant effort on the torque ripple” line 91, effort or influence?

7.      “the process of motor rotation”, what is (this process)?

8.      Line 93: “analyzed by FEM”, more in detail: static or transient analysis, if transient then at what speed? What software is used? The common or a good practice is to include flux density distribution for the machine at no-load and nominal operation e.g.  line 116 – magnetic circuit saturates, elaborate more on the performance due to saturation and include FEM analysis figures.

9.      Line 98: Tempus: “will be analyzed” or actually is analyzed in this article.

10.   Line104: “width of the motor permanent magnets Bpm sets to range from 3° to 10.5°” width is in mm and not degrees (as a unit) (comment 2)

11.   Line 119: “cost of permanent magnet”, the cost analysis is not really topic for this article, but reduction of PM material used is.

12.   Line 120: in “Figure 3(b) to express”, this graph needs a much deeper explanation of what it shows. Is there an attempt to show the constant torque control of an electric machine and the values are obtained from there? Is that so? If so, how the control is implemented? is it possible to demonstrate the periodicity of the torque and at what current values is it calculated (like Fig. 7)? Here it is assumed that static torque characteristics as a function of rotor position relieve the torque ripple peak-to-peak value shown in Figure 3(b)? At what current? Consider that left figure (a) has 3 different lines and colors while (b) has only one

13. The previous comment is also valid for Figures 4(b) and 5(b)

14.   Line 145: “At the winding excitation currents from 0A to 5A show in Figure 5”, previously maximum current 1.8 A, now 5?

15.   Line 175: “Obviously, the higher Spm, the more permanent magnet efficiency”, or more flux and saturation, flux density distribution would be nice to see. (Use Fig 1 and create a post-processing image with flux lines and flux density distribution)

16.   Table 2, width – are angular dimensions appropriate for parallel sided “blocks”? (Comment 2)

17.   Line 179, “Box-Behnken decision space”, what it is? Refer. How these 13 test points are initiated, explain. What is the outcome if the number of test points is different?

18.   Line 187, “accuracy of the fitted model” as a matter of fact, more interesting is the accuracy of the FEM model compared to the prototype machine, it would be good if the verification is more addressed in the article.

19.   Line 226, “structure shows in Figure 8.” –> structure shown in Figure 8.

20.   Explain whether Fig. 8 rotor geometry is used in Fig. 7 in achieving the results for the optimized rotor and is the original motor based on Figure 1. It is recommended providing pictures of the flux density distribution for both machine designs.

21.   Concerning to Fig. 9(b) and Fig. 10(b) look at the comment 12.

22.   Figure 13, does not tell much about the FSPM machine or its calculation. Would it be possible to address the analysis of induced voltage and flux linkage instead?

23.   Figure 14, as the test machine requests more current as it is expected, then what this can tell about the losses and efficiency of the machine? Can the no load losses be measured when torque sensor is attached and the servo is used at elevated speeds: 100, 200, 300, ..., rpm?

24.   Figure 15, the magnetic hysteresis losses is part of the friction experienced in this experiment. It would be nice if the paper addresses more on the materials used for the prototype motor and core loss analysis, since this data is available with the software used in this article.

Comments on the Quality of English Language

are given in comments and suggestion section

Author Response

Dear Reviewer:

We deeply appreciate the time and effort you’ve spent in reviewing on our manuscript ‘The study of the salient pole geometry optimization of the flux switching permanent magnet machine ‘(ID: actuators-3184090). Your comments are really thoughtful and helpful. According to the comments and suggestions, we carefully revised the manuscript.

The reviewer give a lot of suggestions on the paper writing. Including the abstract, introduction and conclusion. Thanks very much on the detailed suggestion on how to make an academic article. These valuable advices are exactly helpful and benefited us a lot. According your advices, the manuscript is revised. Thanks for your review.

 

1. Fig 2. Table 1. And so on: Bpm, Bst, Brt – capital B is conventionally used for flux density respectively in permanent magnets, rotor and stator teeth (according to indexes). The recommendation is to use a small letter b for the breath or width of geometry

Response: Thanks for your advice. The small letter b is used to present the geometric size expression. The correspondence modifications is marked in red in manuscript.

 

2. Why are the dimensions of the poles and magnets given in degrees (table 1) when the drawing (Fig 1) shows the corresponding details of the machine's construction with parallel sides? If angle measurements are necessary, it must be noted at which radius they are specified

Response: Thanks for your question. In response to your confusion, the Figure 1 and Figure 8 has been revised to circular form. The dimensions in the figures can match with the prototype.

 

3. Line 87, show that the flux is sinusoidal and not trapezoidal. Can induced voltage waveforms be shown and verified in the measurement section?

Response: Thanks for your advice. The EMF is calculated in FEM model and made a compassion between the original machine and optimized machine. The no-load EMF test is applied and the results added in manuscript.

 

4. Line 87, what is magneto resistance, is it reluctance?

Response: We apologize that we made a mistake in the use vocabulary. The corrected content is marked in red in the manuscript.

 

5. Line 89, what is “the stability of torque output”, what affects it and how? Best if torque pulsation is shown as a function of rotor position when using constant torque (current) control.

Response: Thanks for your question. In my opinion, the less harmonic content in the output torque, the purer the torque is, which means the torque is more stable. The ideal torque output curve should be a straight line. The structure of the motor will affect the torque stability. For example, in the PM motor, permanent magnets attached on rotor surface or embedded in rotor will cause different torque output characteristics. This is due to the reluctance difference during rotation. The geometric dimension sizes of the motor structure also affect the torque stability. For example, the study in the manuscript. The torque pulsation shown as a function of rotor position in Figure 8.

 

6. “significant effort on the torque ripple” line 91, effort or influence?

Response: I apologize; that is a mistake in expression. it has been revised as "significant effect on the torque ripple". And the revised content is marked in red in the manuscript.

 

7. “the process of motor rotation”, what is (this process)?

Response: I apologize that it brings you confusion. The expression is interpreted as "However, the parameter that has the most significant effect on the torque ripple are the salient pole dimensions at the air gap b_st, b_rt and b_pm, which influence the motor winding flux dynamically." And the revised content is marked in red in the manuscript.

 

8. Line 93: “analyzed by FEM”, more in detail: static or transient analysis, if transient then at what speed? What software is used? The common or a good practice is to include flux density distribution for the machine at no-load and nominal operation e.g. line 116 – magnetic circuit saturates, elaborate more on the performance due to saturation and include FEM analysis figures.

Response: Thanks for your question. In this part, the transient analysis carries out on the ANSYS Electronic software. The rotor speed sets at 300rpm. The constant q-axis current excitation is applied in the simulation. The phase current excitations are sine function of rotor position. The stator core material is DW465. The rotor is made of C10 steel. The permanent magnet material is N35H and the coils are copper. The flux density figures are supplied in the manuscript to demonstrate the magnetic characteristics.

 

9. Line 98: Tempus: “will be analyzed” or actually is analyzed in this article.

Response: I apologize for the expression mistake. The sentence is corrected as “The specific parameters are analyzed by FEM in the next section.” The correction is marked in red in manuscript.

 

10. Line104: “width of the motor permanent magnets Bpm sets to range from 3° to 10.5°” width is in mm and not degrees (as a unit) (comment 2)

Response: Thanks for your comment. This problem is caused by the unreasonable expression of the geometric parameter. The new Figure 1 has been modified to correspond to the geometric dimensions of the prototype, and these width dimensions in the circular direction are in deg units.

 

11. Line 119: “cost of permanent magnet”, the cost analysis is not really topic for this article, but reduction of PM material used is.

Response: Thanks for your comment. The corresponding content are corrected in the manuscript.

 

12. Line 120: in “Figure 3(b) to express”, this graph needs a much deeper explanation of what it shows. Is there an attempt to show the constant torque control of an electric machine and the values are obtained from there? Is that so? If so, how the control is implemented? is it possible to demonstrate the periodicity of the torque and at what current values is it calculated (like Fig. 7)? Here it is assumed that static torque characteristics as a function of rotor position relieve the torque ripple peak-to-peak value shown in Figure 3(b)? At what current? Consider that left figure (a) has 3 different lines and colors while (b) has only one

Response: Thanks for your questions. The explanation of Figure 3 is enhanced in the manuscript. In the simulation, the control plan is constant q-axis current control. The current of each winding can be calculated using the inverse Park and Clark transform with the position of the rotor. The exciting currents are pure sine curves and their phases are the same as no-load EMF waveform. In practice, the excitation of the current in the simulation is a function of the rotor position. The torque control can generally be considered as the control of the q-axis current amplitude. From the simulation and experiments, the current excitation magnitude has little effects on the peak-to-peak values of torque ripple. So that, the 0A current excitation result are used to perform the torque ripple feature. The supplementary statements are added in the manuscript.

 

13. The previous comment is also valid for Figures 4(b) and 5(b)

Response: Thanks for your advice. The supplementary expressions are added in the manuscript.

 

14. Line 145: “At the winding excitation currents from 0A to 5A show in Figure 5”, previously maximum current 1.8 A, now 5?

Response: I apologize, that is a mistake in writing the manuscript. The exact current is 0A to 1.8A. And the correction is marked in red in manuscript.

 

15. Line 175: “Obviously, the higher Spm, the more permanent magnet efficiency”, or more flux and saturation, flux density distribution would be nice to see. (Use Fig 1 and create a post-processing image with flux lines and flux density distribution)

Response: Thanks for your advice. The flux density distribution figures are added in the manuscript.

 

16. Table 2, width – are angular dimensions appropriate for parallel sided “blocks”? (Comment 2)

Response: Thanks for your question. In response to your confusion, the Figure 1 and Figure 8 has been revised to circular form. The geometric dimensions in the figures can match with the prototype.

 

17. Line 179, “Box-Behnken decision space”, what it is? Refer. How these 13 test points are initiated, explain. What is the outcome if the number of test points is different?

Response: Box-Behnken designs are used to construct experiments, and applied computational and graphical methods to analyze the significance of results. In this paper, three factors are coupled optimized. Three factors can be used to define a three-dimensional coordinate system. Each factor has the different level in one dimensional axis. The selection of experimental points is in this three-dimensional space. The Box-Behnken designs provide a cube box in the three-dimensional space. The cube box has 13 points to evaluate the coupled relationship among the three factors. The 13 points consist of 12 middle point of the edge of the cube and 1 center point of the cube. Actually, the design points can be 15 or more. More experimental points can provide more fitting data. However, in this case, the result composed of 13 points can express the relationship between the three factors significantly. Therefore, the selection of 13 points is sufficient, which can also reduce workload and improve efficiency during calculation.

 

18. Line 187, “accuracy of the fitted model” as a matter of fact, more interesting is the accuracy of the FEM model compared to the prototype machine, it would be good if the verification is more addressed in the article.

Response: Thanks for your advice. In considering the ability of this test bed, some verifications are applied and stated in the manuscript including the no-load EMF, speed test and torque test. We will continue to improve the motor and test bench to carry out more research work in the future.

 

19. Line 226, “structure shows in Figure 8.” –> structure shown in Figure 8.

Response: Thanks for your comment. The corresponding content are corrected in the manuscript.

 

20. Explain whether Fig. 8 rotor geometry is used in Fig. 7 in achieving the results for the optimized rotor and is the original motor based on Figure 1. It is recommended providing pictures of the flux density distribution for both machine designs.

Response: In Figure 8, the geometric parameters are the same as Figure 1 except the A_rt and D_rt. The optimization result in Figure 7 is an intermediate result. We supplemented final results in Figure 7 and placed it in the statement of final optimization. The flux density distribution is also added in the manuscript.

 

21. Concerning to Fig. 9(b) and Fig. 10(b) look at the comment 12.

Response: Thanks for your advice. The supplementary expressions are added in the manuscript.

 

22. Figure 13, does not tell much about the FSPM machine or its calculation. Would it be possible to address the analysis of induced voltage and flux linkage instead?

Response: Thanks for your advice. Taking into account existing experimental abilities, no-load EMF test results of the motor are added to the manuscript. Magnetic field measurement cannot be performed on the test bed, so there is no relevant experimental verification of the flux linkage. We will continue to improve the experimental equipment for further research.

 

23. Figure 14, as the test machine requests more current as it is expected, then what this can tell about the losses and efficiency of the machine? Can the no load losses be measured when torque sensor is attached and the servo is used at elevated speeds: 100, 200, 300, ..., rpm?

Response: Thanks for your question. The loss of motor is indeed a very important research content. Honestly, the study of prototype loss is inappropriate. The rotor of the prototype is made of a block of C10 steel. This type of rotor has little effect on the torque ripple study at low speed, but its loss is much higher than that of silicon steel sheet laminates. This kind of solid block rotor is generally not used in the product, so it is of little significance to the study prototype loss. Subsequently, we will improve the rotor structure in order to study its losses. Thank you for providing a very important research point. We will also continue our efforts to carry out research in this regard.

 

24. Figure 15, the magnetic hysteresis losses is part of the friction experienced in this experiment. It would be nice if the paper addresses more on the materials used for the prototype motor and core loss analysis, since this data is available with the software used in this article.

Response: Thanks for your advice. The magnetic hysteresis loss is significant topic in the motor research. However, due to the structure limitation of this prototype, the experiment of its loss test is inappropriate, so we will consider the subsequent modification of the rotor structure to carry out the loss research. Thank you for your advice on increasing the research points.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed the comments and revised the article. They have improved the scientific content and the editing layer of the paper.

I recommend the paper for publication.

Author Response

1. The authors have addressed the comments and revised the article. They have improved the scientific content and the editing layer of the paper. I recommend the paper for publication.

Response: We would like to thank the reviewer for the constructive suggestions. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. The careful and professional attitude of the reviewer moves us very much. Thanks again for the professional work of the reviewer.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have significantly improved the presentation of the article compared to the original version.

The paper entitled "The study of the salient pole geometry optimization of the flux switching permanent magnet machine” focuses on rotor optimization for a 10-rotor/12-stator pole (PM) reluctance machine, resulting not only in reduced torque ripple but also in increase of its average value. The article has the advantage of having a prototype, and all related tests and comparisons of calculation results add value to this work. The study on the FSPM machine has been carried out at relatively low power (load current and load torque are 0.9 A and 5 Nm respectively, rotation speed up to 500 rpm) considering the size of the machine (rotor and stator core diameter Ø99 and Ø202 and thickness H67 mm). 

As the paper mainly focuses on torque ripple calculation and experimental evaluation, the following correction is mandatory:

1. use brt, bst and bpm in equation (2) since b (small letter) is used as a parameter for machine construction and B (capital letter) for flux density (in different sections of core and air-gap)

and some suggestions are made to (further) improve the paper (if possible):

2. add the torque ripple measurement result and comparison with a loaded (5 Nm) electric machine

3. evaluate the relationship between the induced voltage spectrum and the torque ripple spectrum (5th (Fig. 14) in back emf,  6th and 12th in torque (Fig. 16) in this article)

4. evaluate and discuss the results and conclusions of the work in the context of other similar research papers on 10/12 FSPM machines, paying attention to both ripple reduction methods and related optimization methods and results

Some suggested articles:

Hua, Wei; Cheng, Ming; Zhu, Z. Q.; Howe, D.; "Analysis and Optimization of Back-EMF Waveform of a Novel Flux-Switching Permanent Magnet Motor", 2007 IEEE International Electric Machines & Drives Conference, 2007, pp.1025-1030 

Zhu, Dehong; Shen, Chenpu; Du, Yi; Xiao, Feng; "Pole-shape optimization of flux-switching permanent magnet machine", 2014 17th International Conference on Electrical Machines and Systems (ICEMS), 2014, pp.1681-1684

Zhu, Xiaofeng; Hua, Wei; "Back-EMF waveform optimization of flux-switching permanent magnet machines", 2016 XXII International Conference on Electrical Machines (ICEM), 2016, pp.2419-2425

Ullah, Wasiq; Khan, Faisal; Umair, Muhammad; "Multi-objective optimization of high torque density segmented PM consequent pole flux switching machine with flux bridge", CES Transactions on Electrical Machines and Systems, V 5 n 1, 2021, pp.30-40 

Ma, Zhengzhou; Cheng, Ming; Zhao, Chenchen; "Analytical Investigation and Topology Evolution of Rotor Salient Pole Reluctance in the Flux-switching Permanent Magnet Machine", 2023 26th International Conference on Electrical Machines and Systems (ICEMS), 2023, pp.130-135

Last but not least: core loss and performance analysis of this type of machine would be great interest and since the prototype is already in the test bench it might be interesting topic for future work.

 

Comments on the Quality of English Language

no comments

Author Response

1. use brt, bst and bpm in equation (2) since b (small letter) is used as a parameter for machine construction and B (capital letter) for flux density (in different sections of core and air-gap)

Response: I apologize that this is an oversight of our last revision. The corresponding contents have been corrected in the newest revised manuscript.

 

2. add the torque ripple measurement result and comparison with a loaded (5 Nm) electric machine

Response: Thanks for your question. In the torque ripple test, we use a servo motor to drive the FSPM motor to rotate slowly and measure the torque value corresponding to motor rotor positions. Because of the slow speed, each sampling point can be considered to reflect the static measurement results. In this way, the influence of rotational resistance on torque measurement is minimized. Through simulation, the torque ripple has little effect on the amplitude of current excitation. Therefore, this measured result can basically represent the characteristics of motor torque ripple. The above measures are to avoid the external torque affecting the measurement of torque ripple. In the load test, the load torque is provided by the magnetic powder brake. However, the torque generated by the magnetic powder brake is not smooth and uniform. If the torque ripple is measured on the existing platform under the loaded situation, the measurement results are mixed by the FSPM torque ripple and the torque ripple of the magnetic powder brake. The results are difficult to distinguish. Therefore, if the appropriate high-precision torque load device is available in the future, the test will be applied.

 

3. evaluate the relationship between the induced voltage spectrum and the torque ripple spectrum (5th (Fig. 14) in back emf, 6th and 12th in torque (Fig. 16) in this article)

Response: Thanks for your advice. The spectrum of EMF and torque ripple are added in the manuscript to express the frequency characteristics. The corresponding explanations are also added. From the results of EMF and torque, there is no obvious correlation between their spectral characteristics.

 

4. evaluate and discuss the results and conclusions of the work in the context of other similar research papers on 10/12 FSPM machines, paying attention to both ripple reduction methods and related optimization methods and results

Response: Thanks for your question. The articles have different focuses on the improvement of FSPM machines. There are many geometric factors that constitute the actual structure. Some researchers have chosen single factor optimization (only rotor or stator), and some have chosen partial factors and applied multi-factor optimization. Regardless of the choices, these factors do have a certain influence on the motor performance. The optimization methods used in the articles are mostly mature; they have been proven feasibility before. In considering that every researcher’s FSPM motor is unique, every study has value and significance. They all solve problems in their own situations. The ideas are instructive. So, it is hard to evaluate whose method was better or not.

 

5. Some suggested articles:

Response: Thanks for your advice. The articles you suggested are helpful and significant to our research. After carefully reading these articles, we updated references in the revised manuscript.

 

6. Last but not least: core loss and performance analysis of this type of machine would be great interest and since the prototype is already in the test bench it might be interesting topic for future work.

Response: Thank you. Your suggestion is very important and significant. After improving the rotor structure, the corresponding efficiency research will be put on the agenda. My sincere thanks to you for your guidance on article writing and scientific research.