Research on Control of Levitation Force and Torque of a Maglev Device for Water-Turbine Generator Set
Round 1
Reviewer 1 Report
The work by Liu et al. tackles the problem of ever-increasing pressure on bearings by applying maglev technology. The authors demonstrated this technology by applying it on a vertical shaft hydro-generator and showing the reduction in load by positive levitation force. The analytical calculations for the levitation force and torque are shown and are also supported by FEA. Furthermore, the authors have also built a prototypical system for testing and compared the results from the prototype against FEA. Dynamical mathematical models are shown and test results on the controlled experiment on the prototype show effective force addition and torque cancellation. This is a thorough work by the authors and is suitable for this journal. I believe this work will enhance understanding for future studies in this direction. I am happy to recommend this work for publication after addressing some of the specific comments/questions below:
· Abstract, line 20, “the controller is improved to improve” Please change this sentence for better readability.
· Page1, line 27: “of which 13401 billion”. I believe the authors mean 1340.1 billion.
· Page3, Figure2: This figure needs improvement. The arrows are not visible clearly. The authors should label and clarify direction of all forces and torque explicitly for general readers. Also, instead of “reverse” using “negative” will be more appropriate.
· Page3, line100: Please define FEA for the first time for general readers.
· Page4, Figure4: y-axis has units of torque, the authors should clarify it in the caption to avoid confusing readers.
· There are several grammatical and spelling mistakes. Please have it reviewed. Some examples- page12, line306; page12, line310
Author Response
Please see the attachment, thank you!
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The Maglev technology is studied and applied to large vertical shaft hydro-generator set to solve the bearing problem. The dynamic mathematical models of levitation force and torque are derived. Combined with the design and theoretical analysis, the vector control strategy is developed, and the simulation analysis is completed. The control experiment is carried out on the prototype.
The authors fail to place their work in a context of scientific literature. Only 4 from 12 cited references are current (within the last 5 years).
The manuscript is missing the truth validation for the results obtained in the research (discussion part). It is suggested to add the limitations of this study in the discussion section.
Chapter "Conclusions" is absent. The conclusions should be consistent with the evidence and arguments presented.
Formatting and English language problems:
The text from lines 303-312 should be placed between Figures 12-14.
Impersonal mood should be used in the manuscript. Some typing mistakes are noticed, for example - line 216 "congtrol", line 287 "linkge", line 310"cayyied", etc.
Given the above flaws, the manuscript cannot be accepted.
Author Response
Please see the attachment, thank you!
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The manuscript has been corrected according to my remarks.
Please pay attention to unfinished sections "Acknowledgments" and "Conflicts of Interest".
Author Response
Reviewer: Please pay attention to unfinished sections "Acknowledgments" and "Conflicts of Interest".
Response: Thank you for you review and advice, and we finished the sections "Acknowledgments" and "Conflicts of Interest".
Author Response File: Author Response.pdf
