Multi-Objective Computational Aided Design Tool Using Pareto Analysis

Round 1

Reviewer 1 Report

1. Abstract text must be in 'justify' format.

2. Equation 2, do you need dt for the integration.

3. What if thermal capacitance is also consider? Generally, non-idealities, non-linear effects must be considered.  

4. GitHub for mCAD may make available for evaluation. There is lack of information on how to use mCAD to achieve the designs.

5. There is not evaluation to show that the design is optimized.

6. Table 2, Table 3, the efficiency is only at a specific load? There is also generally not comparison to conventional design. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript presents an interesting optimization tool but the major flaws are also very obvious. Please consider my following comments:

1. There are major formatting mistakes in the paper. Even the abstract is not properly formatted. 

2. The title of the manuscript does not highlight what is in the text. I think the title needs revision. 

3. No connection between the paragraphs of the introduction and conclusion section. Very small paragraphs make very bad impressions and are very confusing. 

4. Results are not presented professionally. Please enhance the colors and size of the labels and markers. 

5. I am unable to understand from the write-up whether the case study was simulation-based or experimental. I think if it is simulation-based then the authors should at least explain in the discussion how this would be implemented experimentally. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

3. What if thermal capacitance is also considered? Generally, nonidealities, non-linear effects must be considered.

"Thank you very much for the inquiry. The effects of thermal capacitance were not considered because the electrothermal model in steady state was considered sufficient for this work."

The authors have not responded to this recommendation fully, as "Generally, nonidealities, non-linear effects must be considered."

 

4. GitHub for mCAD may be available for evaluation.

"There is a lack of information on how to use mCAD to achieve the designs. The tool is being implemented to be more generic. For the UPS application we cannot make it available at this time due to intellectual property issues."

The authors have not responded to this recommendation. If IP is involved, patent pending, or another example can be given. There is no way to know how mCAD works. 

 

5. There is no evaluation to show that the design is optimized.

"Within the evaluated range of frequencies and current ripple, the observed points presented the highest values of power density and efficiency. In addition, they were compared with an experimental design already presented in the literature."

The authors have not responded to this recommendation fully. To get if it is optimized, other conditions are also required to be evaluated, and provide theoretical justification of 'optimized condition'. 

 

 

 

 

Author Response

3. What if thermal capacitance is also considered? Generally, nonidealities, non-linear effects must be considered

• Thank you for your inquiry. Sorry, if we haven't made our answer clear. We have not considered the thermal capacitance of the semiconductors and the heatsink in our analysis because we are focused on steady state behavior of an UPS system, we also assume that the converter design incorporates a safety margin in relation to the maximum junction temperature defined by the semiconductor manufacturer, thus the thermal cycling that the pulsating power dissipation on the switches would not reach dangerous values. We understand that this approach gives a conservative design for the heatsink and a precise thermal modeling of the thermal impedance could eventually lead to a shorter safety margin, hence to a reduced volume. However there are several challenges for that kind of modelling, since datasheet information from most heatsink manufactures does not consider the impact on thermal impedance due to the placement of multiple heat sources, thus this precise modelling would require to experimentally raise the behavior of multiple heatsinks for different assemblies or to include a FEM simulation inside the algorithm loop, either way we did not had the resources to incorporate that in our tool. What we did incorporate was the adjustments on the general thermal resistance due to heatsink length variation, temperature rise variation and the influence of forced ventilation. In our interpretation this approach, although leads to a conservative design, can give the designer the optimal solution in terms of which heatsink profile (that exists in the database, i.e., would be available for that designer) to use and in which dimensions and we understand this to be useful for the design of real converters. 

 

4. GitHub for mCAD may be available for evaluation.

• We are sorry if we didn't give a satisfactory answer. As we explained, this mCAD tool is a product of industry funded research and a cooperation between our University and a Private UPS manufacturer. The tool is being developed as a proprietary software to be used by this company, therefore, we are not allowed to disclosure the code and database construction to the broad public and we cannot distribute the software, not even in its preliminary form. Our partner has decided not to patent the software but also not to open its development, we can only publish the results and the basic theory behind the modelling of the software. Therefore, unfortunately we cannot deploy it on Github as asked.

  5. There is no evaluation to show that the design is optimized

• Sorry if we did not give a satisfactory answer. We emphasize that the main idea of the tool is to rely on a database that possesses only components that a particular company has in their stock, our can/desire to acquire. It is not intended to find the theoretical optimal design (although if a large database is available it could), but the optimal design among all feasible solutions that could be built with the available components. The software sweeps the database and computes multiple design combinations between the components and offers the designer in a visual form all solutions found, so the designer could choose the solution that best suits his/her needs, in this sense the designer can choose the optimal point from all possible solutions. For the sake of comparison, we have used the tool to compare the design an UPS developed in another paper (in our lab) that used a more straightforward design approach, where we have selected the optimal solution found (in terms of the pareto front) to be used in this comparison and showed how distant from the optimal solution a conventional design approach can be.

Reviewer 2 Report

Thank you for the revision. 

Author Response

Thank you very much.

Round 3

Reviewer 1 Report

The authors have addressed the recommendation to their extend but limited by IP and patent issue.