A Battery Cell Equalisation System Based on a Supercapacitors Tank and DC–DC Converters for Automotive Applications
Round 1
Reviewer 1 Report
Dear Editor
This study investigated a battery cell system based on a supercapacitors tank. The main advantages of the developed system are the utilization of the regenerative brake energy for battery cell equalization, reducing the number of the DC-DC converters, flexible operation expressed by the possibility to address each battery cell with bidirectional switches, and acceptable efficiency in all modes of operation.
1. Introduction needs to introduce different types of supercapacitors such as the following references: CNTs-Supercapacitors: A Review of Electrode Nanocomposites Based on CNTs, Graphene, Metals, and Polymers
2. All equations need a reference
3. Figure 3 is clear and can be omitted
4. Figures 5 and 6 can be ignored
5. Experimental setup section needs to be improved with compare the results of this work with other reports
6. Conclusion needs to be supported with data results
7. The conducted experimental verification confirms the working capacity of the designed system, the possibility of completing all modes of operation, the stable operation of the designed converters and SCES, and the lack of oscillations and thermal losses in the converters and bidirectional switches…please clearly explain in detail in the results section.
Additional comments:
Dear Editor
1.What is the main question addressed by the research?
· This study investigated a battery cell system based on a supercapacitors tank. The main advantages of the developed system are the utilization of the regenerative brake energy for battery cell equalization, reducing the number of the DC-DC converters, flexible operation expressed by the possibility to address each battery cell with bidirectional switches, and acceptable efficiency in all modes of operation.
2. Do you consider the topic original or relevant in the field? Does it address a specific gap in the field?
· Yes, this article is in the field of battery, hybrid, and electric vehicles.
3.What does it add to the subject area compared with other published material?
· The conducted experimental verification confirms the working capacity of the designed system, the possibility of completing all modes of operation, the stable operation of the designed converters and SCES, and the lack of oscillations and thermal losses in the converters and bidirectional switches.
4. What specific improvements should the authors consider regarding the methodology? What further controls should be considered?
· All equations need a reference
· Experimental setup section needs to be improved with compare the results of this work with other reports
· Please clearly explain in detail the results in the Experimental setup section.
5. Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed?
· Conclusion needs to be supported with data results
6. Are the references appropriate?
· Introduction needs to introduce different types of supercapacitors such as the following references: CNTs-Supercapacitors: A Review of Electrode Nanocomposites Based on CNTs, Graphene, Metals, and Polymers
7. Please include any additional comments on the tables and figures.
· Figure 3 is clear and can be omitted
· Figures 5 and 6 can be ignored
Author Response
Please see the attached file.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The submitted manuscript presents the design of a supercapacitor-based energy storage system for automotive applications aimed at battery cells balancing. The topic is rather interesting both for the power electronics and the automotive communities. Overall, the manuscript is well written and it clearly presents the objective of the Authors' research. However, some comments are due.
In the Introduction Authors could further improve their literature review by recalling cases of adoption of supercapacitors on-board electric/electrified vehicles to manage the available power. For instance, in [Supercapacitor stability and control for More Electric Aircraft application, 2020 European Control Conference (ECC), St. Petersburg, Russia, 2020, pp. 1909-1914] and [Control of Supercapacitors for smooth EMA Operations in Aeronautical Applications, 2019 American Control Conference (ACC), Philadelphia, PA, USA, 2019], supercapacitors, controlled by DC/DC converters, were designed to absorb/provide fast power peaks of electromechanical actuators onboard the so-called More Electric Aircraft. This methodology allows to reduce the stress on the mechanical parts of the aircraft main generator and can be in future translated to the case of electric aircraft. Moreover, Authors presented some interesting simulation results generated through MATLAB. What toolbox was employed to obtain such result? What is simpowersystems, electronics or the result of the equations presented in the manuscript? Please, add more details about this aspect. Equation (4) represents the energy stored in the capacitor, not its power. Line 278, CC usually stands for constant current, not current charging. In Section 3.2, dealing with the bidirectional DC/DC converter analysis and design, what is the control algorithm designed and implemented to control this converter? How was it tuned? Please, recall the converter control algorithm equations. Images, especially those representing simulationr results, have rather low quality. Please, provide higher quality images and consider generating vector images for improved resolution.
No major comments about quality of english language.
Author Response
Please see the attached file.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear Editor
The manuscript well has been revised
Reviewer 2 Report
Authors have correctly replied to the Reviewers' questions. No further changes are required.
