Analysis and Experimental Validation of Single-Phase Cascaded Boost AC–AC Converter with High Voltage Gain

Round 1

Reviewer 1 Report

This paper proposes a Boost AC-AC converter that is tested in simulation and with a real circuit. In my opinion, it has some lacks and details that should be corrected or better explained:

- The title of the paper states that the converter have "High Voltage Gain". Does this refer to the use of "high voltage", or to a "high gain"? This is not clear.

- The reference numbers are not correct. For example, in line 30 one of the references is [20]. How are the references ordered? They should be put in order of apparition in the text.

- "The second is matrix converters are used in situations where both the voltage magnitude and frequency must be changeable". Please, review the grammar of this sentence.

- "which allows for variable the output frequency and voltage at the expense of complicated modulation and a greater switch count". Please, review the grammar of this sentence.

- "The cascaded converter based on the conventional AC /AC converter has a commutation problem for each unit. It has not been well supported with phase-shift PWM control.". These two sentences are very categorical, so these should have some supporting references if possible. Please, add some references that supports these statements.

- "Moreover, the Power Factor (PF) for inductive loads is not improved". It is not improved in comparison to what?

- "In addition, the control system is very complicated due to the complicity of operation states". Do you mean "complexity" instead of "complicity"? What do you mean with "complicated", i.e., what is the characteristic that make it complex? the equations, the implementation of the system, ...?

- In line 85. There is a space located before a dot which should be put after such dot.

- In general, the aspect of the Figures should be improved. The font cannot be clearly seen (their color is not plain, but it is fuzzy in some letters), plus some of them have bad proportions (e.g., Figure 3 is distorted, it is wider that needed). Please, unify their color and sizes.

- You use a lot of colors for the figures of electronic circuits, but maybe you do not need so many colors. Unless the colors are mean to add clarity to your explanations, please, reduce the number of colors in the schemes.

- In line 200, maybe you want to write "Where" instead of "Were"?

- Sections 2 and 3 are too short. Maybe you could combine both of them in a single section.

- The caption of Figure 9 says "Converter of bode plot diagram." Do you mean "Bode plot diagram of the converter"?

- Figure 11 and 13 have a little graph inside the graph. What does this represent? It should be explained.

- Figure 12 and many other figures have a little sinusoidal line in the top. What does this represent? It should be explained in the Figure captions, in case it is important to keep it.

- Could Sections 6 and 7 be combined (as both of them refer to experimental results)? This is only a suggestion. If you think that it is more clear as it is now, keep them separated.

- The Conclusion Section is too short in my opinion. It is not clear what the novelty of the proposal is. This should be clarified together with a summary of the literature review that you did in the Introduction.

- "The system size and cost have been reduced significantly". Reduced in comparison to what, other solutions from the literature? This should be clarified and briefly explained here.

Author Response

Thank you very much for your careful review. Please find the attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments:

-The performance of the proporsal can be compared with existing studies in detail.

-There are some grammatical errors and typos.

-The various control and converter topologies should be reviewed. The following paper can be overviewed.-https://doi.org/10.1016/j.jpowsour.2022.231788

-Motivation and contributions of the paper should be more highghted in Abstract and last pragraph of Introduction Sections.

-In Fig. 2, what are contributions of the propose control? I know that this control approach is exist in the literature.

-Explanations are not clearly given for Figures. The more explanations should be given for them.

-The results Section should be more clearly presented.

-There are some grammatical errors and typos.

Author Response

Thank you very much for your carful review. Please find the attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper is interesting but some improvements are needed

1.. The presentation and quality of figures 1, 3, 4, 5, 6, 7, 8 must improve.

2.. In line 162 there is an error in the alignment of the paragraph.

3.. After a number you must make a space and then put the units, for example looking  at the table 15mH must be changed to 15 mH (leaving a space), make these corrections throughout the entire document.

4.. In general, improve and unify the size of the letters of the axes of the figures, all the figures must have an adequate size which must be the same for all.

5.. In line 247 you make a change of load, please make more disturbances in the load to see the behavior in the current and in the voltage at the output. This can be done in the simulation.

6.. If it is possible to put a voltage reference at the output with another type of frequency, for example 30 or 120 Hz to see its behavior and robustness.

7.. In general, the presentation of all the results should be improved, looking for uniformity in the graphs, font and size.

8.. A list of contributions of the paper should be made, please add it at the end of the introduction.

9.. The conclusions should be improved, with respect to the objectives and contributions of the paper.

Author Response

Thank you very much for your careful review. Please find the attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The paper have been corrected from the last review, so it is now more suitable for being published.

There are still some details that could be improved in my opinion:

- Some of the figures still have bad proportions. The figure 1 should have more relative height for the letters not to be distorted. The same happens with figures from 3 to 8 and 10-19, 23-28, 30-33, 36, 40-47, 49, 50. Please, adjust them.

- In figures 1 and 3-8 you have put a blue background. I am not sure that this blue color help to see the figure more clearly, maybe you could consider supressing this blue color. This is not mandatory, just a suggestion. Moreover, in Figure 1 the two blue zones have a black outline which is not present in the others, so please unify the image style to be all the same.

- The caption of Figure 1 says "converter for n unit". Check if it should be "converter for n units".

- Table 2 is too wide. Please, adjust for it to fit in the page respecting the recommended margins.

- In figure 29, the background of the text blocks have a too dark color (navy blue). Please, consider using a lighter color for the text to be read easier.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

Thank you very much for the above corrections and congratulations for the paper.

The AC source in the figures should be round in shape, not in the shape of an ellipse, not elongated to the horizontal. The above is also presented in the letters Ls1, Vcn, Vs and others, please correct this in all figures.

Bibliographic multi-references should be avoided, for example [1-9],[15-22]., each paper should be cited separately with its respective contribution.

Figures (1, 3, 4, 5, 6, 7, 8) may improve when the blue background is removed

Author Response

Please see the attachment

Author Response File: Author Response.pdf