Comparative Study of a Buck DC-DC Converter Controlled by the MPPT (P&O) Algorithm without or with Fuzzy Logic Controller
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsDear colleague, Your work is of interest to me. I will provide some comments which may help you improve it.
You are comparing results from two different control methods, one with fuzzy logic and one without it; there are many MPPT methods in the literature; how did you choose the one you used, and why didn´t you include a comparison with other methods? Please comment.
It seems you published an article some years ago that may be related to this work, but it wasn´t cited in this manuscript.
Livinti, P. Comparative Study of a Photovoltaic System Connected to a Three-Phase Grid by Using PI or Fuzzy Logic Controllers. Sustainability 2021, 13, 2562. https://doi.org/10.3390/su13052562
Due to the relationship of the works, it must be cited. Please comment on the findings of the two articles.
In Fig. 1, the input voltage is shown as Uint but then is referred to as Uent; please use the same expression in all cases. Please comment and explain a bit about the four resistors you have in the gate of the IRF4095.
Did you use a photovoltaic panel? In Fig. 17, it seems you used a voltage source; in that case, how did you test the MPPT? You mentioned a higher quantity of electrical energy can be harvested with the controller you tried; how much energy? Can you include those energy measurements?
Comments on the Quality of English Language
The English grammar is ok. There are a few improvements, mainly non-common expressions in American English. One example is listed here (the English revision is not exhaustive).
Sometimes the word “convertor” is used, but “converter” is more common in the field. We also don´t use the expression “voltage variator”, we call them “voltage regulator”.
Author Response
Answer to Review 1
Dear Sir,
Many thanks, first of all, for your remarks and suggestions.
- You are comparing results from two different control methods, one with fuzzy logic and one without it; there are many MPPT methods in the literature; how did you choose the one you used, and why didn´t you include a comparison with other methods? Please comment.
1: I chose the simplest version for the MPPT algorithm – perturb and observe and made a comparison to the intelligent MPPT algorithm with fuzzy logic controller. A better efficiency on the photovoltaic systems will be obtained through this study in case of using the MPPT algorithm with fuzzy logic controller. The conventional MPPT algorithm perturb and observe has been implemented with the help of a function in the MATLAB program that allowed writing the program in the programming language C++. The MATLAB function has been included to the program in Simulink. I have also implemented this algorithm to the practical manufacture of the buck type DC-DC converter controlled through the development board Arduino Uno. I developed in this work a comparative study between the conventional MPPT algorithm and the Hybrid intelligent algorithm MPPT equipped with fuzzy logic controller.
- It seems you published an article some years ago that may be related to this work, but it wasn´t cited in this manuscript. Livinti, P. Comparative Study of a Photovoltaic System Connected to a Three-Phase Grid by Using PI or Fuzzy Logic Controllers. Sustainability2021, 13, 2562. https://doi.org/10.3390/su13052562 Due to the relationship of the works, it must be cited. Please comment on the findings of the two articles.
2: The article ”Comparative Study of a Photovoltaic System Connected to Three Phase Grid by Using PI or Fuzzy Logic Controllers” presents the control of a three-phase invertor with the help of a PI or Fuzzy Logic controller. I did not use a DC-DC converter in the structure of the photovoltaic system and for this reason I did not refer to that work released in 2021.
- In Fig. 1, the input voltage is shown as Uint but then is referred to as Uent; please use the same expression in all cases. Please comment and explain a bit about the four resistors you have in the gate of the IRF4095.
3: I used the same notation for voltage, Uent. The 4 resistors are forming a passive dumper with the purpose to reduce several harmonics of the PWM signal supplied by the development board Arduino Uno without modifying the signal amplitude. In corrected the notations in the electric diagram. Instead of the transistor IRF4095 I put the transistor BC 107.
- Did you use a photovoltaic panel? In Fig. 17, it seems you used a voltage source; in that case, how did you test the MPPT? You mentioned a higher quantity of electrical energy can be harvested with the controller you tried; how much energy? Can you include those energy measurements?
- Under laboratory conditions I used an adjustable voltage source instead of the photovoltaic system. I elaborated a program in the programming environment Arduino IDE for implementing the algorithm Perturb and Observe. In inserted a table with the results being obtained in the laboratory. In the table it may be noticed the increase of the filling factor of the PWM signal that controls the power transistor in the structure of the photovoltaic system. The increase of the power of the photovoltaic system has been provided through the increase of the voltage of the voltage source controlled through the current intensity.
Sincerely, Livinti Petru
Answer to Review 2
Dear Sir,
Many thanks for your remarks. Please find below my answers to them.
- The overall organization of this manuscript needs to be greatly improved.
- I modified the structure of this work. I also inserted the paragraphs 1.1 Literature Review and 1.2 Contributions to the Work Achievement.
- The abbreviation, in the title, i.e., MPPT, is confusing.
- I presented the meaning of the MPPT algorithm applied through the method Perturb and Observe, in the work. The shortened denomination appears in other article titles, as well: [1], [2], [21], [22].
- Notably, the research background should be further strengthened and the descriptions of existing research should be further summarized in introduction.
- I added other references as well and detailed the results being obtained. A new paragraph was inserted: 1.1 Literature Review.
- In order to make it easier for readers to grasp the key points, the contributions should be refined and listed point by point.
- I clearly mentioned which are the original contributions in this work. I also inserted the paragraph 1.2. Contributions to the Work Achievement, in Introduction.
- Due to the inability of fuzzy algorithms to adapt, the proposed algorithm has a
limited range of applicability. However, many adaptive fuzzy controllers have been
proposed. Therefore, the innovation of this article should be further emphasized.
5: The innovation in this work consists of introducing the fuzzy logic controller for the model built in Simulink for the algorithm Perturb and Observe with the help of a function in the MATLAB program. A comparative study has been done in this work between the conventional MPPT algorithm and the hybrid MPPT algorithm with fuzzy logic controller. I inserted ref. [22] where a study has been presented with regard to the usage of the conventional MPPT methods and intelligent MPPT methods. In ref [22] it is mentioned that hybrid MPPT methods are more efficient.
- Significantly, some expressions should be added with corresponding references, as
they are not the first time proposed, such as:
(7)
6: I provided references for the respective relations. [23]
- The stability analysis of the entire closed-loop system is missing.
7: In this work the fuzzy logic controller has been used. This has been designed based on a basis of rules established on experience and assures the system stability.
- Images 8-11 are blurry and unclear.
8: Figures 8-11 have been reviewed.
- In the validation section, other methods should be compared.
9: I compared the results obtained through the conventional MPPT algorithm to the results obtained through the hybrid intelligent MPPT algorithm, please refer to Table 2 – Results obtained through simulation.
- Some already existing methods, which are widely utilized these days to solve several real world problems including the described issues, multilayer neurocontrol of high-order uncertain nonlinear systems with active disturbance rejection, asymptotic tracking with novel integral robust schemes for mismatched uncertain nonlinear systems and so on.
10: I did not use a control system concerning the active rejection of perturbations. This issue may be treated in another work. In this work I used the intelligent MPPT with fuzzy logic controller.
Sincerely, Livinti Petru
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsPlease see the comments in the uploaded file.
Comments for author File: 
Comments.pdf
Minor editing of English language required.
Author Response
Answer to Review 2
Dear Sir,
Many thanks for your remarks. Please find below my answers to them.
- The overall organization of this manuscript needs to be greatly improved.
- I modified the structure of this work. I also inserted the paragraphs 1.1 Literature Review and 1.2 Contributions to the Work Achievement.
- The abbreviation, in the title, i.e., MPPT, is confusing.
- I presented the meaning of the MPPT algorithm applied through the method Perturb and Observe, in the work. The shortened denomination appears in other article titles, as well: [1], [2], [21], [22].
- Notably, the research background should be further strengthened and the descriptions of existing research should be further summarized in introduction.
- I added other references as well and detailed the results being obtained. A new paragraph was inserted: 1.1 Literature Review.
- In order to make it easier for readers to grasp the key points, the contributions should be refined and listed point by point.
- I clearly mentioned which are the original contributions in this work. I also inserted the paragraph 1.2. Contributions to the Work Achievement, in Introduction.
- Due to the inability of fuzzy algorithms to adapt, the proposed algorithm has a
limited range of applicability. However, many adaptive fuzzy controllers have been
proposed. Therefore, the innovation of this article should be further emphasized.
5: The innovation in this work consists of introducing the fuzzy logic controller for the model built in Simulink for the algorithm Perturb and Observe with the help of a function in the MATLAB program. A comparative study has been done in this work between the conventional MPPT algorithm and the hybrid MPPT algorithm with fuzzy logic controller. I inserted ref. [22] where a study has been presented with regard to the usage of the conventional MPPT methods and intelligent MPPT methods. In ref [22] it is mentioned that hybrid MPPT methods are more efficient.
- Significantly, some expressions should be added with corresponding references, as
they are not the first time proposed, such as:
(7)
6: I provided references for the respective relations. [23]
- The stability analysis of the entire closed-loop system is missing.
7: In this work the fuzzy logic controller has been used. This has been designed based on a basis of rules established on experience and assures the system stability.
- Images 8-11 are blurry and unclear.
8: Figures 8-11 have been reviewed.
- In the validation section, other methods should be compared.
9: I compared the results obtained through the conventional MPPT algorithm to the results obtained through the hybrid intelligent MPPT algorithm, please refer to Table 2 – Results obtained through simulation.
- Some already existing methods, which are widely utilized these days to solve several real world problems including the described issues, multilayer neurocontrol of high-order uncertain nonlinear systems with active disturbance rejection, asymptotic tracking with novel integral robust schemes for mismatched uncertain nonlinear systems and so on.
10: I did not use a control system concerning the active rejection of perturbations. This issue may be treated in another work. In this work I used the intelligent MPPT with fuzzy logic controller.
Sincerely, Livinti Petru
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsMy comments have been addressed. Thank you.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe comments have been considered.
Comments on the Quality of English LanguageMinor editing of English language required.
