Selective Harmonic Elimination in a Cascaded Multilevel Inverter of Distributed Power Generators Using Water Cycle Algorithm

Round 1

Reviewer 1 Report

The manuscript presents research related to improving the efficiency of power electronic devices with application in energy. An optimization algorithm for determining the optimal switching angles of the semiconductor switches is proposed in order to achieve a certain harmonic composition in the output of the electronic converter. The advantages of the new control are proven by comparison with the use of other optimizations, and for this purpose the results of numerical modeling are presented. Overall, the work is well written and structured and my overall assessment is positive. My main remarks and comments are as follows:
- As many notations and abbreviations are used in the text, I recommend authors to add a list of notations used at the beginning or end of the manuscript.
- I would recommend the authors to describe in more detail the mathematical model on the basis of which the results are presented;
- In addition to the advantages in the conclusion section, it would be useful for the authors to comment on the shortcomings of the proposed optimization procedure. In this way you will get a complete picture of its qualities, capabilities and limitations for implementation.

Author Response

The authors appreciate the time and efforts of the editor and the reviewers in
evaluating this manuscript. The authors have incorporated all the suggestions
in the revised manuscript. The authors have also addressed all the raised issues.
In this document, we propose detailed responses to the editor and the reviewer
comments and questions. All the revisions are marked in red in the revised
manuscript.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors proposed a metaheuristic algorithm called the water cycle algorithm (WCA) for eliminating harmonics in a seven-level cascaded H-bridge multi-level inverter. The results of the manuscript were evaluated with the other two algorithms (PSO and FA). In general, the manuscript is written and presented in a well way. In the following, there are many comments; I think they are useful to enhance the manuscript.

1. Please, support the abstract section with numerical facts to show the superiority of the proposed model.
2. Please, write the full name of the acronym “MLI” in line 30.
3. Please, write the full name of the acronym “EMI” in line 35.
4. Please, revise the numbering regarding the results and analysis section and conclusion section to be “5” and “6” instead of "7" and "8", respectively in lines 109-110.
5. Please, cite the figures in context as “Figure” to be identical to that in the figures’ caption (see “Fig. 2” on page 4, “Fig. 3” in line 132, “Fig. 5” in line 165).
6. I suggest writing the acronym “no or No” as a full name “number”.
7. I think Eq. 13 should be revised to be “FFi = FF(r1, r2, r3, · · · , rNvar )”.
8. Please, define “Cost_i” in Eq. 16.
9. In line 145, the authors mention “dmax is a small number”. What is the range of dmax values?
10. Please, justify why does ν is chosen 0.1?
11. Please, justify the setting values of population size, the number of iterations, dmax, …etc. that are mentioned in the Table1 for WCA.
12. What did the authors mean by the sentence “a1, a2, and a3 represent the switching angles at different values of modulation index.”, which is mentioned in lines 177-178.
13. Please, write the figure's number (I think it has to be 8) instead of double question marks in line 178.
14. According to Figures 9-11, the WCA needs more iterations to obtain minimum fitness function values when the modulation index is increased. Please, explain why does that be?
15. The manuscript needs for language polishing because it has some grammatical mistakes and typos such as “connverges” in line 228.

Author Response

The authors appreciate the time and efforts of the editor and the reviewers in
evaluating this manuscript. The authors have incorporated all the suggestions
in the revised manuscript. The authors have also addressed all the raised issues.
In this document, we propose detailed responses to the editor and the reviewer
comments and questions. All the revisions are marked in red in the revised
manuscript.

Author Response File: Author Response.pdf