Research on Hybrid Approach for Maximum Power Point Tracking of Photovoltaic Systems under Various Operating Conditions
Round 1
Reviewer 1 Report
Comments and Suggestions for Authorsthe paper present two part one is a theoretical results and one about the experimental wich it very well and good idea.
what the authors did not add the comparison between the theoretical results wich he can add various methods and algorithms in her results presented in figures; 10, 11 , 14, 15 and 16.
the title is about controller but in the paper I find only optimisation wicth all are about optimisation algorithms.
where is the part about control??!!
in table 3 the authors compare PSO , WOA , WOA-PO and IWOA-PO present this comparison in figures 11, to 16.
the experimental results are the comparison between the theoretical and experimental and after calculating the statistical errors metric to conclude about the results.
for example IAE, RE R².........
Author Response
Dear Editor and Reviewer,
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using IWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
The paper present two part one is a theoretical result and one about the experimental which is very well and good idea.
Response: Thank you very much for your appreciation and your valuable and constructive suggestions! They are all very valuable and helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied all the comments carefully and have made corrections which we hope meet with approval. And the revised portions are marked in red.
We will do more researches and look forward to your helpful guidance again in future.
The following is point-to-point responses to all of your constructive and helpful comments.
Comments 1: What the authors did not add the comparison between the theoretical results wich he can add various methods and algorithms in her results presented in figures; 10, 11, 14, 15 and 16.
Response 1: Thank you for giving us valuable and constructive suggestions. Actually, we compare the four algorithms, such as in Figure 10 (Figure 11, Figure 14 and Figure 16, in which figs. (a)-(d) respectively the simulation comparison of PSO, WOA and WOA-P&O and ICWOA-P&O algorithms. In order to better show the advantages of the proposed algorithm and the comparison of various algorithms, according to your suggestions, we have plotted the table and added the comparison of simulation results with theoretical results in the revised manuscript, as shown in the simulation results and analysis section of revised manuscript.
Comments 2: The title is about controller but in the paper, I find only optimizations which all are about optimization algorithms.
Response 2: Thank you for your important suggestions. According to your suggestions, we have improved the title to "Maximum Power Point Tracking of Photovoltaic systems using a hybrid approach under various operating conditions", which to be more relevant to the research content in the paper. The thesis focuses on optimization algorithms, which are studied in the context of MPPT controllers, where the goal of optimization is to improve the performance of the controller. Optimization algorithms are a core component in modern controller design, especially for MPPT controllers, and our research enhances the efficiency of MPPT controllers through specific optimization algorithms, for example, to improve the tracking of the maximum power point and to improve the stability of the system. These optimization algorithms play a vital role in MPPT controller design.
Comments 3: where is the part about control?
Response 3: Thank you for your important suggestions. They are very constructive and helpful. According to your suggestions, we have discussed in detail the design and implementation of MPPT control algorithm in the revised manuscript, including the following aspects:The PV system mainly consists of five core components: PV array, DC-DC converter, inverter, MPPT controller and load. The MPPT controller is one of the core components of the PV system, which mainly detects the output current and output voltage of the PV array in real time, and calculates the optimal output control quantity through MPPT control algorithm (such as ICWOA-P&O algorithm). The control quantity is usually the duty cycle of the PWM signal, mainly used to drive the MOS tube in DC-DC converter to turn on and off to achieve boost or buck control. By adjusting the output voltage of the DC-DC converter, the MPPT controller adjusts the equivalent resistance of the load to match the impedance of the PV array with the load. The process of ensuring that the PV array always operates near the MPP.
Comments 4: In table 3 the authors compare PSO, WOA, WOA-PO and lWOA-PO, present this comparison in figures 11. to 16.
Response 4: Thank you for your important suggestions. They are quite constructive and helpful. According to your suggestions, we have double-checked all the data in Table 3 and Figures 11 to 16, and in order to compare the simulation results more clearly, we split the performance comparison of algorithms in Table 3 and add them to the corresponding figures 11 to 16 section respectively, and added a more detailed analysis description.
Comments 5: The experimental results are the comparison between the theoretical and experimental and after calculating the statistical errors metric to conclude about the results.
Response 5: Thank you for your important suggestions. They are quite constructive and helpful. According to your suggestions, we have plotted the table to compare the theoretical results with the experimental results and calculated the results after calculating the statistical errors, as shown in Table 8 of revised manuscript.
Once again, thank you very much for your comments and suggestions. We will do more researches and look forward to your helpful guidance again in future.
Sincerely,
Qingyun Yuan
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper presents a hybrid MPPT that combined an advanced heuristic search engine and then used P&O to refine the local search.
The authors successfully conducted simulations and experiments, where the results are comparable, though the work has no significant contribution to the already saturated MPPT research work.
Comments on the Quality of English Language
the written English is standard.
Author Response
Dear Editor and Reviewer,
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using IWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
Comments and Suggestions for Authors:
Comments：The paper presents a hybrid MPPT that combined an advanced heuristic search engine and then used P&O to refine the local search. The authors successfully conducted simulations and experiments, where the results are comparable, though the work has no significant contribution to the already saturated MPPT research work.
Response: Thank you very much for your appreciation and your valuable and constructive suggestions! They are all very valuable and helpful for revising and improving our paper, as well as the important guiding significance to our researches. In order to further improve the quality of the paper, according to your suggestions, we have made the following modifications.
1. For the suggestions on the introduction, we have further revised and improved the introduction, and added some related references in the revised manuscript.
2. According to the suggestions on the clarity of results, we have added some details about the experimental setup. To further demonstrate the performance of the proposed method, we also have given the performance comparison of PSO, WOA, WOA-P&O and ICWOA-P&O algorithms in Table 8, as shown in the experimental results section of revised manuscript.
3. For the suggestions on the English expression of the manuscript, in order to further improve English quality, we have a careful check about the English expression of the whole manuscript and do our best to revise all of the existing typographical and grammatical errors. Moreover, we also turned to several colleagues who are adept in writing English papers to check our manuscript. We believe that the language is now more acceptable.
Once again, thank you very much for your comments and suggestions. We will do more researches and look forward to your helpful guidance again in future.
Sincerely,
Qingyun Yuan
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThis paper presented a maximum power point tracking (MPPT) algorithm for PV systems. My comments are:
1- The use of abbreviations in the title is not recommended. Please, update the title of the paper.
2- How the authors obtained the parameters of the PV cell equivalent circuit?
3- Fig. 5 is located at the bottom of Page 5 and its caption on the top of page 6, this is not acceptable.
4- How the authors selected the coefficient of the WOA?
5- The proposed IWOA-PO still suffers from oscillations, why?
6- Please, add more details about the experimental setup. How the authors emulate the real PV?
7- The authors selected IWOA-PO as abbreviation for Improved Chaotic Whale fused with Perturbation Observation. I think this is not accurate, please update.
8- Please, improve the quality of the written text.
9- Please, cite these important references:
Shirkhani, M., Tavoosi, J., Danyali, S., Sarvenoee, A. K., Abdali, A., Mohammadzadeh, A.,... Zhang, C. (2023). A review on microgrid decentralized energy/voltage control structures and methods. Energy Reports, 10, 368-380. doi: https://doi.org/10.1016/j.egyr.2023.06.022
Hu, F., Mou, S., Wei, S., Liping Qiu, Hu, H.,... Zhou, H. (2024). Research on the evolution of China's photovoltaic technology innovation network from the perspective of patents. Energy Strategy Reviews, 51, 101309. doi: https://doi.org/10.1016/j.esr.2024.101309
Comments on the Quality of English LanguageMinor editing of English language required
Author Response
Dear Editor and Reviewer,
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using IWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
Comments and Suggestions for Authors: This paper presented a maximum power point tracking (MPPT) algorithm for PV systems. My comments are as follows:
Response: Thank you very much for your appreciation and your valuable and constructive suggestions! They are all very valuable and helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied all the comments carefully and have made corrections which we hope meet with approval. And the revised portions are marked in red.The following is point-to-point responses to all of your constructive and helpful comments.
Comments 1: The use of abbreviations in the title is not recommended. Please, update the title of the paper.
Response 1: Thank you for giving us valuable and constructive suggestions. In order to highlight the proposed methods and correspond to the research content of the paper, according to your suggestions, we have revised and updated the title of the paper, and removed the abbreviation in the title.
Comments 2: How the authors obtained the parameters of the PV cell equivalent circuit?
Response 2: Thank you for your important suggestions. We adopted experimental measurement and curve fitting methods: First, I-V characteristics were measured: using professional test equipment, the current-voltage (I-V) curve of PV cell was measured under different light intensity and temperature conditions. Then, the measured I-V data was imported into special data analysis software (such as Origin), a suitable equivalent circuit model was selected, and the equivalent circuit parameters were determined by fitting the curve.
Comments 3: Fig. 5 is located at the bottom of Page 5 and its caption on the top of page 6, this is not acceptable.
Response 3: Thank you for giving us valuable and constructive suggestions. According to your suggestions, we have adjusted Fig. 5 and its caption to one page, as shown in the revised manuscript. Moreover, we have carefully checked the format of the whole manuscript and revised it to ensure the standardization of the format.
Comments 4: How the authors selected the coefficient of the WOA?
Response 4: Thank you for giving us valuable and constructive suggestions. The selection of coefficients A and C in WOA are related to the control parameters, mainly depending on the control parameters a and r, as shown in Equations (11)-(13) in the revised manuscript, where r1 and r2 are random vectors of [0, 1]. The control parameter a play a crucial role in the convergence speed and search accuracy of the algorithm. In standard WOA algorithm, a decrease linearly from 2 to 0. A larger value of a gives the stronger global search ability of the algorithm , which is conducive to preventing the population from falling into local optima. As the number of iterations increases, the a value gradually decreases, which will enhance the local development capabilities of the algorithm and speed up the convergence speed.
Comments 5: The proposed IWOA-PO still suffers from oscillations, why?
Response 5: Thank you for giving us valuable and constructive suggestions. They are very helpful. ICWOA-P&O combines the global search capability of ICWOA with the local search capability of P&O. However, due to the inherent perturbation mechanism of the P&O algorithm and the convergence property of ICWOA, it may trigger the oscillation problem in dynamic environments. These oscillations mainly arise from ICWOA’s global search by simulating the feeding behavior of whales, but when combined with P&O, precise adjustments still needs to be made at the local scale. If the convergence rate of ICWOA is too fast, it may lead to overreaction to perturbed observations, resulting in oscillations. And the ICWOA-P&O algorithm needs to find a balance between global and local search. Due to the local nature of P&O itself, repeated adjustments and oscillations may occur when the system approaches the maximum power point.
Comments 6: Please, add more details about the experimental setup. How the authors emulate the real PV?
Response 6: Thank you for your important suggestions. They are very constructive and helpful. To show more details about the experimental setup, according to your suggestions, we have added a detailed description of the main equipment and its role in the experiment of the paper, and explained how to emulate really photovoltaic. In addition, to further demonstrate the performance of the proposed method, we have given the performance comparison of PSO, WOA, WOA-P&O and ICWOA-P&O algorithms in Table 9, as shown in the experimental results section of revised manuscript.
Comments 7: The authors selected IWOA-PO as abbreviation for Improved Chaotic Whale fused with Perturbation Observation. I think this is not accurate, please update.
Response 7: Thank you for giving us valuable and constructive suggestions. We are very sorry that we gave an inaccurate description IWOA-PO of the improved algorithm. According to your suggestions, in order to highlight the improvement methods more comprehensively, we have revised and updated the abbreviated name of the algorithm proposed in this paper, and marked it as ICWOA-P&O in the revised manuscript.
Comments 8: Please, improve the quality of the written text.
Response 8: Thank you for your important suggestions. They are quite constructive and helpful. In order to improve the quality of the written text, according to your suggestions, we have a careful check about the English expression of the whole manuscript and do our best to revise all of the existing typographical and grammatical errors. Moreover, we also turned to several colleagues who are adept in writing English papers to check our manuscript. We believe that the language is now more acceptable.
Comments 9: Please, cite these important references:
Shirkhani, M., Tavoosi, J., Danyali, S., Sarvenoee, A. K., Abdali, A., Mohammadzadeh, A.,... Zhang, C. (2023). A review on microgrid decentralized energy/voltage control structures and methods. Energy Reports, 10, 368-380. doi: https://doi.org/10.1016/j.egyr.2023.06.022.
Hu, F., Mou, S., Wei, S., Liping Qiu, Hu, H.,... Zhou, H. (2024). Research on the evolution of China's photovoltaic technology innovation network from the perspective of patents. Energy Strategy Reviews, 51, 101309. doi: https://doi.org/10.1016/j.esr.2024.101309.
Comments on the Quality of English Language: Minor editing of English language required.
Response 9: Thank you for giving us valuable and constructive suggestions. According to your suggestions, we have added the above references in the revised manuscript.
Once again, thank you very much for your comments and suggestions. We will do more researches and look forward to your helpful guidance again in future.
Sincerely,
Qingyun Yuan
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for Authorsthe iThenticate after Revision 28%
in the Abstract add the statistical errors and compare your method with other methods to conclude which method has the best results.
the stat of the arts in the introduction is very small you need to discuss the most used methods
compare all your results with other methods
Author Response
Dear Editor and Reviewer,
Thank you for your letter and for the reviewer’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using ICWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
Comments 1: the iThenticate after Revision 28%.
Response 1: Thank you for giving us valuable and constructive suggestions. According to your suggestions, we have revised the paper and reduced the similarity index of the paper to 22%.
Comments 2: in the Abstract add the statistical errors and compare your method with other methods to conclude which method has the best results.
Response 2: Thank you for your important suggestions. According to your suggestions, we have revised and improved the logic of the abstract to better and more clearly express the main innovation of the proposed ICWOA-P&O MPPT method, in addition, we have incorporated the relative error (RE), tracking accuracy and tracking time into the abstract for analysis, and compare proposed method with other methods to show its advantages.
Comments 3: the stat of the arts in the introduction is very small you need to discuss the most used methods.
Response 3: Thank you for your important suggestions. They are very constructive and helpful. According to your suggestions, we have improved and perfected the introduction by incorporating some of the most commonly used MPPT control methods and demonstrating their advantages and disadvantages in the text, further introducing the idea of the proposed method in this paper.
Comments 4: compare all your results with other methods.
Response 4:Thank you for your important suggestions. They are very constructive and helpful. According to your suggestions, we have further improved and perfected the paper. To show that advantages of the proposed method, we have comprehensively compared the tracking performance of ICWOA-P&O algorithm with WOA-P&O、WOA and PSO algorithm under four conditions: uniform irradiance, static local shading, dynamic shading and sudden changes in irradiance and temperature, and carried out the simulation and comparative analysis. In addition, in the section of summary and experimental results, we have added some performance indicators and further described in detail the comparative analysis of the proposed method and other methods to show the advantages of the proposed method.
Once again, thank you very much for your comments and suggestions. We will do more research and look forward to your helpful guidance again in the future.
Sincerely,
Qingyun Yuan
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe author has re-write some of the core parts of the manuscript. However, I have detected some error that need to be imporoved:
1. Figure 17: NO legend on the components of the system. Which one is the PV simulator?
2. The combination of CIWOA and P&O. As previously mentioned by me, the hybrid combination will definitely overcome the original MPPT algorithm. However, the author has compared it with another hybrid MPPT, which is good attempt. But based on my literature, P&O is known to have oscillation at steady-state condition because of its nature, it always carry these process purtube and observe, repeatedly. That is why other researchers move away from the P&O especially when the MPPT reach the GMPP. Please comment on that
Author Response
Dear Editor and Reviewer,
Thank you for your letter and for the reviewer’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using IWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
Comments 1: Figure 17: NO legend on the components of the system. Which one is the PV simulator?
Response 1: Thank you for giving us valuable and constructive suggestions. We are very sorry that we did not clearly mark the device names in Figure 17. According to your suggestions, to increase the clarity of charts and readability of the paper, we have labeled the components of the system in Figure 17 and clearly indicated the PV simulator.
Comments 2: The combination of ICWOA and P&O. As previously mentioned by me, the hybrid combination will definitely overcome the original MPPT algorithm. However, the author has compared it with another hybrid MPPT, which is good attempt. But based on my literature, P&O is known to have oscillation at steady-state condition because of its nature, it always carry these process purtube and observe, repeatedly. That is why other researchers move away from the P&O especially when the MPPT reach the GMPP. Please comment on that.
Response 2: Thank you for your important suggestions. Due to the Perturb and Observe (P&O) method leading to power oscillations under steady-state conditions, it continuously perturbs the system and observes the response to determine whether the Maximum Power Point (MPPT) has been reached. As you mentioned that this method is prone to oscillations, especially on a flat power curve where the power remains relatively stable. This is one of the reasons why some researchers have shifted to other methods, particularly when dealing with the Global Maximum Power Point (GMPP). However, the reasons for using the P&O method in the paper areas follows: The P&O algorithm is widely popular due to its simple principle and low implementation cost. It can quickly respond to power changes and effectively track the MPP under various operating conditions. However, when the PV array is affected by partial shading, the P&O is prone to local optima and may exhibit significant oscillations under steady-state conditions. Therefore, this paper integrates an intelligent optimization algorithm, selects the WOA and improves it to enable the PV array to escape from the local optima in shadow. By combining the improved ICWOA, it is possible to reduce or eliminate oscillations while retaining the ease of implementation and real-time adjustment advantages of the P&O algorithm. Moreover, experimental tests have further shown that ICWOA-P&O can accurately find GMPP with the shortest tracking time and minimal fluctuations. Through this combination, the ICWOA-P&O hybrid algorithm retains the fast response advantage of P&O while enhancing the system's stability and accuracy under steady-state conditions, effectively avoiding the steady-state oscillation problem of the traditional P&O algorithm. In addition, P&O has high adaptability and can respond to various environmental changes. For instance, in practical applications where sunlight and temperature may fluctuate frequently, P&O’s simple adjustment mechanism enables it to quickly adapt to these changes. Combined with ICWOA’s global search capability, P&O helps maintain stable power output locally, ensuring effective operation under dynamic conditions.
Once again, thank you very much for your comments and suggestions. We will do more research and look forward to your helpful guidance again in the future.
Sincerely,
Qingyun Yuan
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsِِAccept in present form.
Comments on the Quality of English LanguageِِAccept in present form.
Author Response
Dear Editor and Reviewer,
Thank you for your letter and for the reviewer’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using ICWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
Response: Thank you again for your valuable comments and recognition of this paper. These comments have provided us with many valuable insights that will not only help improve this paper, but it will also guide my future academic research. We will do more research and look forward to your helpful guidance again in the future. Once again, I extend my heartfelt thanks to you! Wishing you success in your work and good health!
Sincerely,
Qingyun Yuan
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
Comments and Suggestions for Authorsfigure 14 , 16 must be in one figure
Author Response
Dear Editor and Reviewers,
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using ICWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
Comments 1: figure 14 , 16 must be in one figure.
Response 1: Thank you for your important suggestions. They are quite constructive and helpful. According to your suggestions, We have combined Figures 14 and 16 into one figure as requested, and also provided a zoomed-in view of the key parts.
Once again, thank you very much for your comments and suggestions. We will do more research and look forward to your helpful guidance again in the future.
Sincerely,
Qingyun Yuan
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors have made efforts into answering all my concerns
Author Response
Dear Editor and Reviewer,
Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled "Photovoltaic power generation systems MPPT controller optimization using ICWOA and P&O: A hybrid approach under various operating conditions" (Manuscript ID: electronics-3128709). These comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance for our researches. We have studied comments carefully and have made corrections which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responses to the Editor and Reviewer comments are as follows:
Response: Thank you again for your valuable comments and recognition of this paper. We sincerely appreciate your thoughtful guidance and assistance throughout the process. Your valuable insights have played a crucial role in improving our work, and we have gained a great deal from this learning experience. We greatly value this opportunity and look forward to seeking your advice in the future. Once again, thank you for generously sharing your time and expertise, and for the tremendous support and help you have provided us!
Sincerely,
Qingyun Yuan
Round 4
Reviewer 1 Report
Comments and Suggestions for AuthorsAccept
