Study on the Effect of Hydraulic Energy Storage on the Performance of Electro-Mechanical-Hydraulic Power-Coupled Electric Vehicles

Round 1

Reviewer 1 Report

The proposed solution should be better justified, since the authors state some limitations regarding storage systems, which are not considered for current allowed performance. I think the authors should better present the main advantages of the proposed solution, which seems to be not aligned to current trends of technology.

Also regarding simulation, it seems not well addressed the approach to combine simulink and AMESim, since AMESim allows also the implementation of the control logic algorithms. Also in this case, it seems a choice not alligned to current possibilities offer by modern simulation software. Therefore, the authors should explain this approach.

Author Response

Point 1: The proposed solution should be better justified, since the authors state some limitations regarding storage systems, which are not considered for current allowed performance. I think the authors should better present the main advantages of the proposed solution, which seems to be not aligned to current trends of technology.

Response 1: Energy storage is used to assist electric vehicles and can improve the short battery life of pure electric vehicles. The energy recovery efficiency of electric vehicles with the addi-tion of energy storage is improved and the driving range of the vehicle is significantly in-creased. For our system, there are some other advantages that have been listed in the text. The first paragraph in the picture shows some of the advantages of the energy storage device, and the second paragraph is for the advantages specific to our system.The specific modifications are shown in the attachment.

Point 2: Also regarding simulation, it seems not well addressed the approach to combine simulink and AMESim, since AMESim allows also the implementation of the control logic algorithms. Also in this case, it seems a choice not alligned to current possibilities offer by modern simulation software. Therefore, the authors should explain this approach.

Response 2: AME Sim also has control strategies, but they cannot produce effective control for our hybrid powertrain. We can build our own control strategy in Simulink. So we choose the joint simulation approach. In the paper i added the model built in Simulink and the joint approach of the two software.The specific modifications are shown in the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is concerned with developing a new electromechanical hydraulic power coupling drive system for electric vehicle application. Very interesting work however i have some few comments.

1. For analysis of the proposed system, include the gradient on the drive cycle. Also can use other drive cycle with different gradient, this is in order to validate performance of the proposed hydraulic power coupling.

2. In section 2.1 start with text and the you can add Fig. 1 within text. The caption of the figure not good at all, please describe the figure more appropriately in the caption.

3. Line 148 to 152, please rephrase the sentences, your point is not clear.

4. Line 201 in section 3, needs to be rephrased, does not make sense. Line 231, "Where." remove the full store after were, and use small letter "w" for where (please correct throughout the paper). 

5. Line 270, avoid equations in a sentence, font is different for, P1 = P0, also dE/dP0, avoid equations in the sentence.

6. Overall, i choose to reject this paper on the bases that it is not an Electronics paper, it does not belong under this track of the MDPI journal. 

Author Response

Point 1: For analysis of the proposed system, include the gradient on the drive cycle. Also can use other drive cycle with different gradient, this is in order to validate performance of the proposed hydraulic power coupling.

Response 1: For our proposed system, it does need to be verified with other drive cycles of different gradients as well. We have verified it with many different operating conditions in our study.

Point 2: In section 2.1 start with text and the you can add Fig. 1 within text. The caption of the figure not good at all, please describe the figure more appropriately in the caption.

Response 2: Figure 1 shows the structure of an electro-mechanical-hydraulic power-coupled electric vehicle and describes what the main components are. The working principle of the fit between these structures is described in section 2.2. For the description of the diagram, I have made some additional explanations.

Point 3: Line 148 to 152, please rephrase the sentences, your point is not clear.

Response 3: This paragraph describes the characteristics of our proposed electro-mechanical-hydraulic power coupled vehicle compared with the conventional hybrid vehicle, which is able to recover, store and reuse hydraulic and electrical energy, and the main power of the vehicle is electrical energy. In this regard, I have recounted it again. As shown in the figure below.

Point 4: Line 201 in section 3, needs to be rephrased, does not make sense. Line 231, "Where." remove the full store after were, and use small letter "w" for where (please correct throughout the paper).

Response4: The content of line 201 is in the explanation of the previous sentence there is a hydraulic accumulator as an auxiliary working conditions, there are vehicle starting, vehicle climbing and other working conditions. All "where" in the entire article has been corrected.

Point 5: Line 270, avoid equations in a sentence, font is different for, P1 = P0, also dE/dP0, avoid equations in the sentence.

Response 5: I have modified the sentence of equation in the text.

Point 6: Overall, i choose to reject this paper on the bases that it is not an Electronics paper, it does not belong under this track of the MDPI journal.

Response 6: Regarding the MDPI journal, I have seen articles about electric vehicles before. Although we are not a pure electric vehicle, we propose an electromechanical-hydraulic power coupled vehicle, which is also powered by electric energy. We have effectively transformed and utilized the interplay between electric energy, hydraulic energy, and mechanical energy. We have mainly studied the effect of adding electrical energy on the performance of the car and also the SOC of the battery in the car. I have revised the article and hope that the teacher will consider it again. 

The specific modifications are shown in the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have correctly replied to the reviewer comments.

Author Response

Thank you very much for your review.

Reviewer 2 Report

Here are some comments:

1. Some of my comments were not addressed, for e.g. point 2, i had suggested that Fig.1 should not start the section but rather have text first, the caption of the figure does not describe the figure well, i had suggested that it be changed, this was not done. 

2. Regarding point 6, i still do not see how this work fits in under an "Electronics" journal, even the mathematical modeling of the proposed system is mechanical, not much electronics content (from eq. 1 to 18, there is more mechanical modeling than electronics).

3. Reference 34 is missing in the reference list. It does not also exist in the text. 

4. The writing and gramma still needs improvement. 

 

Author Response

Point 1: Some of my comments were not addressed, for e.g. point 2, i had suggested that Fig.1 should not start the section but rather have text first, the caption of the figure does not describe the figure well, i had suggested that it be changed, this was not done.

Response 1: Teacher, I'm so sorry. Due to my wrong understanding, it was not corrected properly. I have readjusted the order of the picture and the text, and also changed the title of the picture.

Point 2: Regarding point 6, i still do not see how this work fits in under an "Electronics" journal, even the mathematical modeling of the proposed system is mechanical, not much electronics content (from eq. 1 to 18, there is more mechanical modeling than electronics).

Response 2: Thank you very much for your comments, I have added two more parts, motor and battery, in the mathematical modeling part of the article. The motor and battery are also really the core parts of this electro-mechanical-hydraulic power coupled vehicle of ours. I should have to model them to reflect their importance. Although we are not a pure electric vehicle, our vehicle is also powered by electric energy. The vehicle has electric energy involved in the process of acceleration, uniform speed, hill climbing and deceleration. It is the addition of electric energy that improves the energy consumption problem of traditional fuel cars and reflects the superiority of electric energy. Through this revision, I hope my teacher will consider my article again and I appreciate that he can give valuable comments again.

Point 3: Reference 34 is missing in the reference list. It does not also exist in the text

Response 3: There is no reference 34 in the article. I'm really sorry that I deleted it in the last modification, but the serial number was not deleted. It has been modified now.

Point 4: The writing and gramma still needs improvement.

Response4: Thank you for your reminding. I have made some changes to the grammar of the article.

Some of the content is shown by pictures in the attachment, and the specific changes are in the article. Thank you for your review.

Author Response File: Author Response.pdf