Chattering Free Sliding Mode Control and State Dependent Kalman Filter Design for Underground Gasification Energy Conversion Process

Round 1

Reviewer 1 Report

The paper deals with the subject of the non-linear strategy represented in the sliding mode control, where a new strategy was introduced. Good topic. The paper needs modifications in order to consolidate the work done. Among these notes I mention:

1. The introduction needs modifications, especially in the first part.

2. Several new strategies have been introduced to SMC, addressing how to overcome chatter and improve durability. Among these works, I mention the following:

Benbouhenni, H.; Bizon, N. Third-Order Sliding Mode Applied to the Direct Field-Oriented Control of the Asynchronous Generator for Variable-Speed Contra-Rotating Wind Turbine Generation Systems. Energies 2021, 14, 5877. doi: 10.3390/en14185877

Ibrahim Y., Semmah A., Patrice W. Neuro-Second Order Sliding Mode Control of a DFIG based Wind Turbine System. Journal of Electrical and Electronics Engineering 2020, 13(1), 63-68.

Hamid, Ch.; Aziz, D.; Seif Eddine, Ch.; Othmane, Z.; Mohammed, T.; Hasnae, E. Integral sliding mode control for DFIG based WECS with MPPT based on artificial neural network under a real wind profile. Energy Reports 2021, 7, 4809-4824. https://doi.org/10.1016/j.egyr.2021.07.066.

Quan, Y.; Hang, L.; He, Y.; Zhang, Y. Multi-Resonant-Based Sliding Mode Control of DFIG-Based Wind System under Unbalanced and Harmonic Network Conditions. Appl. Sci. 2019, 9, 1124. https://doi.org/10.3390/app9061124.

3. Please, amend the contribution section in proportion to the work done, mentioning the main objectives obtained.

4. What are the pros and cons of the proposed nonlinear strategy?

5. In Figure 2, the traditional strategy (SMC) is better than the proposed strategy (CFSMC). Why? Why is this?

6. In Figure 4, the traditional strategy (SMC) is better than both CFSMC and DISMC. Can you explain this?.

7. In Table 5, the traditional strategy (SMC) is better than both CFSMC and DISMC in terms of erms and pavg. Can you provide a logical explanation?

8. Please, complete a comparison study between the proposed strategy in this work and the nonlinear strategies proposed in the following works:

  Benbouhenni, H.; Bizon, N. A Synergetic Sliding Mode Controller Applied to Direct Field-Oriented Control of Induction Generator-Based Variable Speed Dual-Rotor Wind Turbines. Energies 2021, 14, 4437. doi: 10.3390/en14154437

Mansoor A. S., Zubair A. M., Mahesh K., Mazhar H. B., Wind energy integration: Dynamic modeling and control of DFIG based on super twisting fractional order terminal sliding mode controller, Energy Reports 2021, 7, 6031-6043. https://doi.org/10.1016/j.egyr.2021.09.022.

Ravikiran H., Tukaram M., Modified Super Twisting algorithm based sliding mode control for LVRT enhancement of DFIG driven wind system, Energy Reports 2022, 8, 3600-3613. https://doi.org/10.1016/j.egyr.2022.02.235.

Hamza G., Sofiane M., Sami L., Walid K., Habib B. Fractional Order Proportional Integral Super-twisting Sliding Mode Controller for Wind Energy Conversion System Equipped with Doubly Fed Induction Generator. Journal of Power Electronics 2022, 22(8) pp.1357-1357. https://doi.org/10.1007/s43236-022-00430-0.

 

Lat Leily, M. R., Tohidi, S., Hashemzadeh, F., Shotorbani, A. M. Novel sliding mode controller for power control of a doubly fed induction generator in variable speed wind turbine. 2019 Iranian Conference on Renewable Energy & Distributed Generation (ICREDG), Tehran, Iran, 2019, pp. 1-6, doi: 10.1109/ICREDG47187.2019.194147.

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

 

Review report

Title: Chattering Free Sliding Mode Control and State Dependent Kalman Filter Design for Underground Coal Gasification Energy Conversion Process.

 In this manuscript, the authors discuss the fluctuations in the heating value of an underground coal gasification (UCG) process 1 limit its application in the electricity generation, where a desired composition of the combustible 2 gases is required to operate gas turbines efficiently. This shortcoming can be addressed by designing 3 a robust control system for the process. In this paper a model-based, chattering free sliding mode 4 controls (CFSMC) algorithm is designed to maintain a desired trajectory of the heating value of syngas 5 mixture. Apart from robustness, CFSMC yields reduced chattering due to continuous control law, 6 and the tracking error also converges in finite time. To estimate the unknown states required for the 7 controller synthesis, a state-dependent Kalman filter (SDKF) is employed, which is based on the quasi- 8 linear decomposition of the nonlinear model of the UCG process. The simulation results demonstrate 9 that despite the external disturbance and measurement noise the control methodology yields good 10 tracking performance.

General comments:

1.      On page 1, line 3 from below (,) should be remove.

2.      On page number 3, (.) should be at the end of the equation 1.

3.      (.) Should be remove at the end of the Abbreviations.

4.      Actually I am not mentioning all here whole paper should be double check in case of (.) and (,).

5.      The following recently published work related to this work should be add in the literature.

     1. Vishnu Narayan Mishra, M. Raiz, Nadeem Rao, Dunkl analogue of Szasz Schurer beta         bivariate operators, 2022(doi:10.3934/mfc.2022037).

2. V.N. Mishra, K. Khatri, L.N. Mishra, Deepmala; Inverse result in simultaneous approximation by Baskakov-Durrmeyer-Stancu operators, Journal of Inequalities and Applications 2013, 2013:586. doi:10.1186/1029-242X-2013-586.

 

 

 

6.      All reference should be double check.

Recommendations: After minor revision paper may be accept in MDPI. 

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The article deals with current issue. Coal gasification is advantageous because the gas is subsequently easier to work with. But if I understand the article correctly, it is only a theoretical simulation. Comparing this simulation with experimental results in practice would be useful. The article does not correspond exactly to my expertise, so I mainly evaluated the formal aspect (see comments). I propose to accept the article after minor revision, see comments:

Comments:

- In the introduction, I recommend softening the statement „the greenhouse gas emissions due to the combustion of fossil fuels negatively impact the environment and is a major cause of global warming“. This is probably but not clearly proven, so I recommend writing "... may be ...“.

- Figures 2-11: I recommend writing the designation of axes in the form t (h), Hv (kJ/mol), ..., and not in the form t in hr, Hv in kJ/mol, ....

- Figures 3-6: The two slashes in the designation of the vertical axis have an imprecise mathematical meaning. I recommend writing the designation of axes in the form kJ/mol.s, … or kJ.mol^-1.s^-1, … and not in the imprecise form kJ/mol/s, …

- 10 self-citation in one article is quite a lot. Authors should consider whether all self-citations are really important.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Hi

Thank you for your efforts to change and amend the paper.

Author Response

We are grateful to the reviewer for accepting our changes.