Battery-Assisted Battery Charger with Maximum Power Point Tracking for Thermoelectric Generator: Concept and Experimental Proof
Round 1
Reviewer 1 Report
The article describes the implementation and practical verification of a battery-assisted battery charger. The presented charger uses a modified configuration of a charger with similar properties already known from the literature [16]. The proposed new charger implementation is equipped with maximum power point tracking (MPPT). The authors write about the use of a thermoelectric generator (TEG) and a photo voltaic generator (PVG) as a source of electricity for charging batteries. However, in the presented tests and simulation results are given only for TEG, which is a significant shortcoming of this article, because the operation of the MPPT procedure in the case of PVG is different, and therefore the authors have not proven the operation of the charger for this case.
The MPPT method used is well known from the literature. Similarly, the circuit diagrams and solutions used are classic and used in similar chargers. The authors should explain exactly what the innovation of the proposed solution is.
Practical tests used a TEG that is heated to 100 degrees Celsius. Such assumption is unrealistic, because such high temperatures are not achieved in the practical environment of sensor operation.
Simulation results are presented in graphs (Figure 12, Figure 14, Figure 15) of very poor quality, the graphs do not indicate numerical values on the horizontal and vertical axes. For this reason, the data are unreadable and unreliable.
Author Response
The authors wish to thank you for providing valuable comments and suggestions. Each has been responded in a revised version of the manuscript. The revised portions in the manuscript were highlighted in yellow. Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The contributions of the proposed work are not clear. In addition, several issues are found in the manuscript, as detailed in the following.
1. There is no consistency in the manuscript; For example, Figure 8 and Figure 9 are discussed before Figure 6 and Figure 7. Similar approach is noticed, while explaining the purpose of each block of Figure 4 in Section 2. They are not exciting and inspiring the readers.
2. The figures 12, 14, and 15 should be improved. They are a bit blurry and pale. No detailed analysis of the results was made.
3. Provide a more comprehensive introduction to the topic. Include a brief overview of previous research in the area and contextualize the novelty and significance of your work. Identify, clear research gap?
4. The authors must explain the role of each block of Figure 4, in more detail. How are these blocks designed and how they perform their respective functions? For time being, the given explanation seems boring.
5. Although, the authors claim that the converter was designed using CMOS 180 nm technology, however no information about the CMOS model parameters is given. The authors must give the CMOS design parameters.
6. How the components values in Table 1 are selected. A detailed step-by-step design methodology must be included in the paper. Also include detail about stability, switch stress, efficiency, gain etc.
7. Does the proposed circuit capable to operate the buck converter in continuous & discontinuous conduction mode.
8. In the conclusion section, reiterate the main contributions and key findings of the research.
Good
Author Response
The authors wish to thank you for providing valuable comments and suggestions. Each has been responded in a revised version of the manuscript. The revised portions in the manuscript were highlighted in yellow. Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have addressed most of my concerns in the revised version of the article.
Author Response
Dear the reviewer,
The authors appreciate your confirmation on the revised version of the manuscript.
Best regards,
Toru Tanzawa
Reviewer 2 Report
Dear authors, the contributions of the proposed work are still not clear. In addition, the response to several comments were unsatisfactory, as detailed in the following.
1. The response to comment #1 is unsatisfactory. The author’s explanation for majority of blocks in Figure 4, is still not exciting and inspiring the readers. For example, a generalize block diagram with infinite D-FF are shown in Figure 6 (a). Did authors design all these blocks shown in Figure 4. If yes, where are the CMOS design parameters?
2. The response to comment #2 is unsatisfactory. Figure 14 and Figure 15 waveforms are a bit pale.
3. The response to comment #3 is unsatisfactory. Please identify a clear research gap? What is the main difference between your proposed work and previous available work? Provide a thorough comparison of the proposed work with existing ones. Highlight the advantages and limitations of the proposed work?
4. The response to comment #7 is unsatisfactory. The information like “Discontinuous mode (DCM) was applied” is too vague. Please also clarify from Figure 9(b), where inductor current looks continuous.
Moderate editing of English language required
Author Response
Dear the reviewer,
The authors appreciate your second review. Please see the attachment. We have updated the manuscript based on your feedback.
Best regards,
Toru Tanzawa
Author Response File: Author Response.pdf
Round 3
Reviewer 2 Report
The quality of the manuscript increased significantly.
Minor editing of English language required
