Backstepping Sliding Mode Control of a Permanent Magnet Synchronous Motor Based on a Nonlinear Disturbance Observer

Round 1

Reviewer 1 Report

The manuscript "Backstepping sliding mode control of permanent magnet synchronous motor based on nonlinear disturbance observer" presents an alternative for the control of permanent magnet synchronous motors. The manuscript is interesting, however there are some issues to be addresed. They are next listed:

- What do the authors understand by control algorithm and control strategy? For the sake of clarity of the paper the authors are encouraged to include these definitions and differences.

- The following statement is misleading: "In addition, the PID 49 controller's response speed to suppress disturbances is relatively slow, and the PID controller is similar to a "black box", it is impossible to derive the changing laws of parameters 51 and disturbances from the external ports." There are several approaches for tuning, robust, tuning, and parameter variation of PID controllers.

- In permament magnet synchronous machines, what kind of model mismatch and disturbances could be said not H2-norm bounded? 

- Equation (13) must be checked.

- Lines 235 and 236 must be checked.

- How restrictive/real are the assumptions that allowed deriving equation (28)?

- All nomenclature items must be defined. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The following are my comments.

1. The authors have done experimental verification, but it is not mentioned in the abstract section.

2. Include the experimental finding, i.e., how much percentage NDO-SMC is better than SMC and I-SMC.

3. Keywords are not properly provided, and it is not sequentially ordered

4. Literature study needs improvement. Refer to newly published papers and revise the paper accordingly. For instance, the authors may refer to 10.1109/ACCESS.2021.3117363, 10.1109/ACCESS.2021.3078608,  10.1109/TMECH.2020.3039967, 10.1109/tii.2019.2949007, 10.32604/EE.2020.013282, etc.

5. Provide proper references for PMSM modeling.

6. Design of the speed controller is not discussed.

7. Is it possible to provide Speed and dq axes current curves?

8. Results are not comprehensively analyzed.

9. What are the drawback and future scope of the controller studied?

10. What are the future scopes of the controller proposed?

11. Correct grammatical mistakes and typo errors throughout the paper.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

This reviewer thank to the authors improving the manuscript. However, there is a concern that still must be addressed:

Why do the authors state that the PID is like a "black box"? There is specialized literature on PID analysis and tuning.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Please check Eq. 8. I am satisfied with the responses provided. 

Author Response

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Author Response File: Author Response.pdf