An Enhanced Sliding Mode Speed Control for Induction Motor Drives

Round 1

Reviewer 1 Report

1. The paper spends most of the derivation part describing what has already been established in the literature (back to 1991), but omits the key derivation of design process using the proposed sliding surface. I have to complain about it because of the following reasons.

1.1. The generic sliding surface in (5) is cool, but your proposed sliding surface cannot be described by (5), not even if you replace $e$ with $arctan(e)$ in (5)---it is still different from your proposed sliding surface. There is no explanation in this manuscript to clarify why you chose not to replace $e$ with $arctan(e)$ in (5) but your particular choice in (23). Your choice makes your design only valid for a first-order system (or a second-order system including the integral of error).

1.2. From (23) to (24), there is a constant term $\rho_\omega$ appearing out of nowhere, and it seems this constant is related to the special definition of arctan in (26). This needs clarification.

2. I am confused about the two distinct definitions of control law $u_\omega$ in (12) and (15). I believe instead of introducing (15), you should directly substitute (16) into (11), assuming current control error is zero.

3. How do you implement (22) in practice?

4. The arctan based sliding surface is proposed to reduce chattering. The authors must compare their design with a second order sliding mode controller (e.g., using super twisting algorithm), because higher-order control is known for reducing chattering and there is no need of calling arctan function in real-time.

Author Response

First of all, the authors would like to express their sincere gratitude to the Editors and the Reviewers who gave us many constructive comments and valuable suggestions in order to improve this paper. The authors have revised the paper according to the reviewers’ comments. The responses to the reviewer comments can be found below their respective comments and the changes made in the paper are marked in blue color.

Author Response File: Author Response.pdf

Reviewer 2 Report

1. Attention should be paid to the content of line 221. If the authors write "Two different design cases", then perhaps they should indicate - "(D1, D2 designs)". In addition, it may be more correct to indicate "Three options ...", since the experiments use: PI, D1 and D2.
2. The authors should explain why the beginning of the graphs (PI, D1, D2) in Fig. 4 and Fig. 6 are shifted in time.
3. It is necessary to clarify the names of the signals, which are displayed in Fig. 4.b. Applied “Sliding Surface” is not correct.

Author Response

First of all, the authors would like to express their sincere gratitude to the Editors and the Reviewers who gave us many constructive comments and valuable suggestions in order to improve this paper. The authors have revised the paper according to the reviewers’ comments. The responses to the reviewer comments can be found below their respective comments and the changes made in the paper are marked in blue color.

Author Response File: Author Response.pdf