An Approval of MPPT Based on PV Cell’s Simplified Equivalent Circuit During Fast-Shading Conditions
Round 1
Reviewer 1 Report
Dear authors,
I appreciate your support by selecting the Electronics Journal for possible publication of your research work.
The paper proposes an algorithm that improves the functionality of MPPT systems, using the information related on upper and lower boundaries of the current and voltage of each photovoltaic panel.
Unfortunately, the paper has points and causes which make me to recommend a major revision of manuscript.
Next I will summarize the most relevant weaknesses in my opinion:
-Proposed control algorithm, described in section 4, must be substantially detailed. The algorithm and the logic diagram have not described how the lower and higher boundaries can be assessed.
-Moreover, it is not clear which are the values of the increment and decrement steps for increasing and decreasing processes depicted in logic diagram.
-Which are the references for searching times values indicate in table 1?
-Some minor errors of typing have to be removed (MMPT in line 242)
Based on the above observations, I recommend a major revision of manuscript.
Best regards.
Author Response
Dear Reviewer,
We are thankful to you for your suggestions and comments. Please find our response given below:
Q1: Proposed control algorithm, described in section 4, must be substantially detailed. The algorithm and the logic diagram have not described how the lower and higher boundaries can be assessed.
Response: Thank you for suggestions. The detailed explanation added in the manuscript (section 3).
Q2: Moreover, it is not clear which are the values of the increment and decrement steps for increasing and decreasing processes depicted in logic diagram.
Response: We are thankful to the reviewer for this comment. Some well-known techniques for GM search such as perturbation and observation (P&O), incremental conductance or another searching procedure can be successfully applied for this purpose. For this research work, we used P&O algorithm with the purpose to achieve zero derivative magnitudes. The values of the steps for increasing and decreasing processes are preferable to use as small as possible. However, we have to consider that the time to find global maximum (GM) increases with decreasing step size. On the other hand, larger step size diminishes the time for GM search but it may cause system instability. In summary, the selected step size in present study provides required stability and a shorter GM search time.
Q3: Which are the references for searching times values indicate in table 1?
Response: The required references are added in table 1.
Q4: Some minor errors of typing have to be removed (MMPT in line 242)
Response: We apologies for such mistakes. We have corrected them in the revised manuscript.
Reviewer 2 Report
The topic is interesting and it is adapt to this journal. The collaboration among several faculties is useful and I think that there is a great work behind the presentation of this work. However, while the presentation is nice in shape, there are few comments and/or suggestions to improve the manuscript.
--According to scientific standards, abbreviations cannot be used in the abstract, please correct it in the manuscript.
--The following structure would be preferable based on the Electronics Microsoft Word template file: 1. Introduction (1.1, 1.2, 1.3.), 2. Materials and Methods (2.1, 2.2., 2.3.), 3. Results and Discussion (3.1, 3.2, 3.3), 4. Conclusions. These sections mixed in the text.
https://www.mdpi.com/journal/electronics/instructions
-PV panel words.
--Are you thinking PV module? The PV panel word is inappropriate. Suitable for example: PV modules, photovoltaic modules, solar PV modules, etc. The ‘solar panel’ means different. Please check the entire text. Easier to understand here:
https://www.mdpi.com/2079-9292/8/2/149
--What is the role of this topic in literature and in international context? Please provide more general information on the importance of PV systems (first general information, then specific). Relevant manuscripts:
https://www.mdpi.com/2079-9292/8/2/149
https://www.mdpi.com/1996-1073/11/10/2615
--It would be necessary to show also real solutions to the problem of partial shading in the introduction. What do you think about the SolarEdge power optimizer technology? This technology effectively solves the partial shading. In this case, what kind of MPPT solution is used? Please add information’s about this technology in the introduction.
https://www.solaredge.com/sites/default/files/se_case_study_commercial_beerot_yitchak_israel.pdf
https://www.solaredge.com/sites/default/files/solaredge-comparative-case-study-ouddorp-nl.pdf
https://www.solaredge.com/us/products/power-optimizer#/
https://www.youtube.com/watch?v=bKcGUSb8hSQ
--For real PV systems, how do the PV module manufacturers solve the problem of partial shading? Please add information’s about this technology in the introduction (Dual MPPT inverters).
https://krannich-solar.com/fileadmin/content/pdf/Germany/Suntech_2018/Smart_DC_Module_english.pdf
--Extend the conclusion with general usability.
--At the end of the study would be necessary to create a nomenclature/abbreviation table.
--The language requires a check by a native English speaker.
Author Response
Dear Reviewer,
We are thankful to you for your fruitful suggestions and comment. It helped us to improve the manuscript. Please find our response to your comments given below:
Q1: According to scientific standards, abbreviations cannot be used in the abstract, please correct it in the manuscript.
Response: Thanks for this suggestion. We have corrected them in the revised manuscript.
Q2: The following structure would be preferable based on the Electronics Microsoft Word template file: 1. Introduction (1.1, 1.2, 1.3.), 2. Materials and Methods (2.1, 2.2., 2.3.), 3. Results and Discussion (3.1, 3.2, 3.3), 4. Conclusions. These sections mixed in the text. https://www.mdpi.com/journal/electronics/instructions
Response: We have modified the manuscript as per your suggestions.
Q3:
-PV panel words.
--Are you thinking PV module? The PV panel word is inappropriate. Suitable for example: PV modules, photovoltaic modules, solar PV modules, etc. The ‘solar panel’ means different. Please check the entire text. Easier to understand here: https://www.mdpi.com/2079-9292/8/2/149
Response: We are thankful for this suggestion. We have modified the manuscript accordingly.
Q4: What is the role of this topic in literature and in international context? Please provide more general information on the importance of PV systems (first general information, then specific). Relevant manuscripts:
https://www.mdpi.com/2079-9292/8/2/149
https://www.mdpi.com/1996-1073/11/10/2615
Response: We are thankful for such suggestions. We have added the advised references in the revised manuscript. We have also added general information about PV systems and present market conditions.
Q5: It would be necessary to show also real solutions to the problem of partial shading in the introduction. What do you think about the SolarEdge power optimizer technology? This technology effectively solves the partial shading. In this case, what kind of MPPT solution is used? Please add information’s about this technology in the introduction.
https://www.solaredge.com/sites/default/files/se_case_study_commercial_beerot_yitchak_israel.pdf
https://www.solaredge.com/sites/default/files/solaredge-comparative-case-study-ouddorp-nl.pdf
https://www.solaredge.com/us/products/power-optimizer#/
https://www.youtube.com/watch?v=bKcGUSb8hSQ
Response: We are thankful for such suggestions. We have added appropriate information about SolarEdge technology in the introduction.
We are aware of the SolarEdge MPPT systems. This is useful and efficient solution to search GM during partial shading conditions. This system is based on the individual MPPT blocks attached to each PV module in the entire string. All these MPPT blocks work together on one DC bus. Therefore, shading situations able to cause multiple maxima and difficulties to find GM are prevented. However, each individual block functioning on its PV module only, which output voltage is relatively low. Today it is 48V maximum. Whereas the MPPT system of the entire string (our case) works with much higher voltages (~1000V) and today even more. Therefore, such an electronic system can be more efficient. For example, individual MPPT blocks have 94-95%% of efficiency whereas MPPT for high voltage strings today can achieve up to 98.5%.
Q6: For real PV systems, how do the PV module manufacturers solve the problem of partial shading? Please add information’s about this technology in the introduction (Dual MPPT inverters).
https://krannich-solar.com/fileadmin/content/pdf/Germany/Suntech_2018/Smart_DC_Module_english.pdf
Response: We are thankful for such suggestions. We have added an appropriate discussion in the revised manuscript.
Q7: Extend the conclusion with general usability.
Response: The conclusion is modified as per your suggestion.
Q8: At the end of the study would be necessary to create a nomenclature/abbreviation table.
Response: We have added a table of nomenclatures/abbreviations in the revised manuscript.
Q9: The language requires a check by a native English speaker.
Response: The revised manuscript is checked by a native English speaker.
Round 2
Reviewer 1 Report
Dear authors,
I appreciate your contributions on the last version of paper and agree with paper publication in Electronics Journal.
Best regards.
