Adaptive Cruise Control Strategy for Electric Vehicles Considering Battery Degradation Characteristics

Round 1

Reviewer 1 Report

This paper studied the adaptive cruise control strategy for electric vehicles considering battery degradation characteristics. I got several comments which I think would be helpful for the improvement of presentation of the paper:

However, battery loss during driving has been less studied when the vehicle is in a following state. What is ‘in a following state’? Why is it important to study this?

Delete the last paragraph of the Introduction.

Equations have not been numbered.

The models in section 2.1, 2.2 are from literatures. What is the novelty here for your study?

Figure quality is very low. Fig. 3, 4, increase front size.

Fig. 6, 7, the text is too small. The resolution is too low.

Fig 10, figure size is too small.

Where is the comparison of modelling and experimental results?

Studies have shown that battery degradation is related to factors such as temperature, charge-discharge rate, depth of discharge, and charge-off voltage. Please add more related refs here, such as diffusion-induced stress: 10.1142/S1758825113500403; 10.1149/1.2185287; 10.1016/j.electacta.2015.10.097

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Well structured paper and a good bibliography. It uses the information of the degradation of the battery of the EV to include in driving control, not so widely studied in literature. Parameters of interest are well discribed. Proposed method increases lifetime of the battery compared to other techniques.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

This article presents a novel idea to develop a cruise controller which considers the impacts of battery degradation, however, there are major issues that should be addressed:

 

- In the last stage of the introduction part, the novelty of this study is not stated clearly.

- The type of the case study vehicle is not stated in the paper; is it a light-duty, medium-duty, or heavy-duty?

- In figure 1, it is suggested to use the term ‘electric drive unit’ or ‘electric machine’ instead of a ‘motor’. Because the motor is representative of an electric motor, however, in figure 1, the generator mode efficiency map is also presented.

- In section 2.3, it is mentioned that the Rint model is used for the estimation of battery parameters in dynamic simulation. To the best of my knowledge, the Rint model does not provide sufficient accuracy for the dynamic simulation of batteries, especially for vehicle modeling applications. How the accuracy of the chosen ECM can be trusted in this study?

- For the proposed Rint model, the OCV, Internal resistance variations in various SOCs are required as input, however, the OCV vs SOC data is only presented in Figure 3.

- There is no reference mentioned for the proposed battery OCV data in the manuscript. What is the source of data? What are the technical specs or the model of the battery proposed in this research?

- In Figure 3, the maximum OCV equals to ~3.7V. Please check since usually the maximum voltage of the battery cells are higher than 4V.

- In section 2.3.2, the last presented equation (the equations should be numbered in the revised version) shows a direct relation between capacity loss and internal resistance loss for the battery, which is not physically valid! There is no such direct relation between the internal resistance fade and capacity fade in batteries. That is why in some relevant research, the SOH will be calculated separately based on internal resistance and capacity.

- In figure 4, why the capacity fade is presented against the current flow? Does this graph show that by increasing of current flow, the capacity fade increases? Is it a definition of degradation? What is the time-related factor in this figure?

- In table 2, the operating temperature for the battery is presented. However, the data presented before does not state that they are related to what temperature? What is the environmental temperature considered for the batteries and what the data is related to? Since the temperature imposes significant impacts on the degradation of the batteries and it is ignored in this paper.

- The proposed driving cycle is not explained in the manuscript text.

- Is the impacts of road inclination in the proposed standard driving cycle considered?

- The electric motor map is representative of its energy conversion efficiency. I would like to ask the authors if they have taken the impacts of inverter/converter losses into account in this study? If yes, is it considered as a constant efficiency or based on an efficiency map?

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thanks for the detailed response, I have no further comments.