Design and Simulation of Inductive Power Transfer Pad for Electric Vehicle Charging

Round 1

Reviewer 1 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

Dear Authors,

general statements about the article:

The article presents a well-structured approach to the design and simulation of an Inductive Power Transfer system with a focus on a new power pad for electric vehicles (EV). The proposed DDC power pad structure combines the advantages of circular and DD power pads to address key challenges in wireless charging,

 

The content is relevant, well written and emphasizes the importance of inductive power transmission systems in electric vehicle applications.

The style of writing needs to be improved, generally.The language is generally clear, but some areas require refining for better readability. All abbreviations must be explained, even the commonly known ones. It is enough to explain the abbreviation WPT (Wireless Power Transfer) only once (Chapter 1), and not several times in this article (chapters 2.2, 3., 3.5, 4.).

Citations are relevant. The references cover a wide range of topics relevant to the research, including EV technology, inductive charging systems, and EMF safety. However, several references appear to be redundant or outdated. While the article cites numerous studies, the inclusion of more recent sources from 2024, would strengthen the theoretical foundation and highlight state-of-the-art developments in the field.

Some figures, such as those illustrating the electromagnetic properties and efficiency curves, could be presented with enhanced resolution and labeling for better readability and interpretation.

The quality of some diagrams needs to be improved (Figure 3.7).  The well-known expression for the resonance frequency does not need to be mentioned (2).

In conclusion, authors should look critically at the contribution of the paper and provide suggestions for improvements in future research. Experimental validation of the simulation results using a prototype would enhance the credibility of the conclusions.

In this research, the student version of Ansys Maxwell 3D (Ansys 2024 R2) software was used, which limits certain functionalities, which could potentially affect the obtained results.

The research offers valuable insights and a promising foundation for future advancements in IPT technology for EVs. It should be emphasized in what direction future research should go and suggest future work with unrestricted (less constrained ) software for validation of results.

Comments on the Quality of English Language

The style of writing needs to be improved, generally.The language is generally clear, but some areas require refining for better readability. All abbreviations must be explained, even the commonly known ones. It is enough to explain the abbreviation WPT (Wireless Power Transfer) only once (Chapter 1), and not several times in this article (chapters 2.2, 3., 3.5, 4.).

Author Response

Response to Comments for Manuscript ID: energies-3313384

 

“Design and Simulation of Inductive Power Transfer Pad for Electric Vehicle Charging"

 

Dear Editors and Reviewers,

 

We would like to begin by expressing our gratitude to the editors and the reviewers for their valuable time and constructive comments. Their expert insights have significantly strengthened our manuscript. In line with the suggestions provided, we have thoroughly revised the manuscript. We have made every effort to address all the comments comprehensively. Our detailed responses to each of the reviewers' comments are provided below.

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Response to the Comments Reviewer 1:

 

The style of writing needs to be improved, generally. The language is generally clear, but some areas require refining for better readability. All abbreviations must be explained, even the commonly known ones. It is enough to explain the abbreviation WPT (Wireless Power Transfer) only once (Chapter 1), and not several times in this article (chapters 2.2, 3., 3.5, 4.).

Citations are relevant. The references cover a wide range of topics relevant to the research, including EV technology, inductive charging systems, and EMF safety. However, several references appear to be redundant or outdated. While the article cites numerous studies, the inclusion of more recent sources from 2024, would strengthen the theoretical foundation and highlight state-of-the-art developments in the field.

Some figures, such as those illustrating the electromagnetic properties and efficiency curves, could be presented with enhanced resolution and labeling for better readability and interpretation.

The quality of some diagrams needs to be improved (Figure 3.7).  The well-known expression for the resonance frequency does not need to be mentioned (2).

In conclusion, authors should look critically at the contribution of the paper and provide suggestions for improvements in future research. Experimental validation of the simulation results using a prototype would enhance the credibility of the conclusions.

In this research, the student version of Ansys Maxwell 3D (Ansys 2024 R2) software was used, which limits certain functionalities, which could potentially affect the obtained results.

The research offers valuable insights and a promising foundation for future advancements in IPT technology for EVs. It should be emphasized in what direction future research should go and suggest future work with unrestricted (less constrained) software for validation of results.

Author Response:

Thank you for your positive feedback and valuable suggestions regarding our revised manuscript. The language has been refined, and all abbreviations have been appropriately adjusted. A more recent paper is cited in the manuscript from 2024. The added lines are highlighted in the manuscript. The added citations are:

• Ahmed, M. M., Enany, M. A., Shaier, A. A., Bawayan, H. M., & Hussien, S. A. (2024). An Extensive Overview of Inductive Charging Technologies for Stationary and In-Motion Electric Vehicles. IEEE Access, 12, 69875–69894. https://doi.org/10.1109/ACCESS.2024.3402553
• Shafiq Z, Li T, Xia J, Li S, Yang X, Zhao Y. Addressing EMI and EMF Challenges in EV Wireless Charging with the Alternating Voltage Phase Coil. Actuators. 2024; 13(9):324. https://doi.org/10.3390/act13090324

Figures are modified with enhancing resolution and labeling for better readability.

The resonance frequency is a well-established concept in the field, and its standard expression is widely recognized. As a result, it is unnecessary to include it explicitly in the analysis, as readers are likely already familiar with it. This allows for a more concise presentation, focusing on novel findings and system-specific evaluations rather than reiterating fundamental principles.

In this research, the Ansys Maxwell 3D Student Version (Ansys 2024 R2) was employed, which imposes limitations on advanced functionalities and simulation scope. These restrictions may impact the precision and comprehensiveness of the results, particularly in modeling complex scenarios or larger physical systems. Despite these constraints, the findings offer valuable insights into the design and performance of the wireless power transfer system, though further validation using the full version of the software could provide more detailed and accurate outcomes.

This research provides valuable insights and a strong foundation for advancing Inductive Power Transfer (IPT) technology for electric vehicles (EVs). Future research should focus on optimizing coil geometry, enhancing misalignment tolerance, and investigating shielding techniques to reduce EMF leakage. Conducting further studies with advanced, unrestricted simulation software would enable more precise validation of the results and expand the scope of the analysis. This approach can refine performance metrics, validate theoretical findings, and drive innovation in IPT systems for practical EV applications.

 

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Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The work presented in this paper focuses on the design and analysis of a wireless power transfer (WPT) system for electric vehicles (EVs), exploring the performance of the newly developed double-delta circular power supply (DDC) structure. The effect of the most influential electromagnetic parameters, such as magnetic flux density, magnetic field strength, coupling coefficient, mutual inductance and efficiency, under different vertical and horizontal misalignments, was analyzed and evaluated. The simulation results obtained by Ansys Maxwell 3D and Simplorer are satisfactory, proving that the DDC structure developed is a promising solution for wireless charging systems for electric vehicles. The following comments need to be considered :

1) The results obtained described in the summary must be quantified in order to be better appreciated.

2) Coil geometry is crucial in determining the performance of wireless power transfer (WPT) systems. In order to improve the value of this study, the addition of a table grouping optimal parameters such as coupling coefficient, inductance, resonant frequency, magnetic field distribution, losses determining better coil efficiency is necessary.

3) The coil thickness used in this work is 0.5 mm. This was compared with a coil thickness of 2 mm, which achieves 90% efficiency for the wireless power transfer (WPT) system. What happens if we further reduce the coil thickness to 0.5 mm for wireless energy transfer performance and practical constraints?

4) The performance of the DDC structure developed in this article as a promising solution for wireless charging systems for electric vehicles deserves to be compared with structures published in the literature?

Author Response

Response to Comments for Manuscript ID: energies-3313384

 

“Design and Simulation of Inductive Power Transfer Pad for Electric Vehicle Charging"

 

Dear Editors and Reviewers,

 

We would like to begin by expressing our gratitude to the editors and the reviewers for their valuable time and constructive comments. Their expert insights have significantly strengthened our manuscript. In line with the suggestions provided, we have thoroughly revised the manuscript. We have made every effort to address all the comments comprehensively. Our detailed responses to each of the reviewers' comments are provided below.

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Response to the Comments Reviewer 2:

 

1. The results obtained described in the summary must be quantified in order to be better appreciated.

Author Response:

We sincerely appreciate your thoughtful feedback and the helpful suggestions you provided for our revised manuscript. The results presented in the summary should include specific numerical values to enhance their clarity and impact. Quantifying key findings, such as the coupling coefficient, mutual inductance, magnetic flux density, and system efficiency, would provide a concrete understanding of the WPT system's performance. For example, specifying that the coupling coefficient reached 0.30 for 0.5 mm thickness and the efficiency peaked at 90% highlights the significance of these achievements. This approach ensures the results are better appreciated and facilitates meaningful comparisons with existing technologies.

 

2. Coil geometry is crucial in determining the performance of wireless power transfer (WPT) systems. In order to improve the value of this study, the addition of a table grouping optimal parameters such as coupling coefficient, inductance, resonant frequency, magnetic field distribution, losses determining better coil efficiency is necessary.

Author Response:

Thank you for your kind feedback and valuable suggestions on our revised manuscript. Coil geometry plays a pivotal role in shaping the performance of wireless power transfer (WPT) systems. To enhance the value of this study, including a table that systematically groups optimal parameters—such as coupling coefficient, inductance, resonant frequency, magnetic field distribution, and loss metrics—would be beneficial. This table would provide a concise overview, facilitating better understanding and comparison of coil efficiency under varying conditions. Such an addition would strengthen the study’s practical implications by offering a clear reference for optimizing WPT coil design.

3. The coil thickness used in this work is 0.5 mm. This was compared with a coil thickness of 2 mm, which achieves 90% efficiency for the wireless power transfer (WPT) system. What happens if we further reduce the coil thickness to 0.5 mm for wireless energy transfer performance and practical constraints?

Author Response:

We truly value your encouraging feedback and the insightful recommendations you offered for our revised manuscript. Reducing the coil thickness to 0.5 mm, as examined in this study, can influence the performance of wireless energy transfer systems. While thinner coils, such as the 0.5 mm thickness, may result in improved coupling coefficients and reduced material usage, they can also lead to lower magnetic field intensity and potentially decreased power transfer efficiency due to increased resistance and reduced energy storage capacity. Practical constraints, including coil durability and manufacturing precision, also become critical at such reduced thicknesses, necessitating a trade-off between performance optimization and practicality in real-world applications.

 

4. The performance of the DDC structure developed in this article as a promising solution for wireless charging systems for electric vehicles deserves to be compared with structures.

Author Response:

We deeply appreciate your kind feedback and the helpful insights you offered regarding our revised manuscript. The performance of the DDC structure developed in this article as a promising solution for wireless charging systems for electric vehicles merits comparison with other existing power pad structures. Such comparisons would provide valuable insights into its advantages and limitations relative to circular and double-D (DD) designs, especially in terms of efficiency, misalignment tolerance, and coupling performance. This analysis could highlight the unique strengths of the DDC structure, further validating its potential for practical applications in wireless EV charging systems.

Author Response File: Author Response.docx

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

This paper concentrated on the design and analysis of a wireless power transfer (WPT) system for electric vehicles (EVs), specifically examining the performance of a double-delta circular (DDC) power pad. The study emphasized the importance of power pad shape, material characteristics, and misalignment tolerances in enhancing electromagnetic performance and power transfer efficiency. There are some comments that need to be addressed in this paper, which are:

1- The author did not take about the perfect distance between the receiving and transmitting coils in his design. They talk about horizontial and vertical misalignment only.

2- There must be curves that show the efficiency and the amount of power transmitted regarding the distance between the receiving and transmitting coils.

3- In page 4, lines 196-197, R1, R2, R3, and R4 represent what and why they are connected in series, not in parallel?

4- There is a model of 15Kw battery used; for how long is it fully charged using the proposed configuration?

5- There is no comparison curve or table between the proposed technique and the DD model.

 

 

Author Response

Response to Comments for Manuscript ID: energies-3313384

 

“Design and Simulation of Inductive Power Transfer Pad for Electric Vehicle Charging"

 

Dear Editors and Reviewers,

 

We would like to begin by expressing our gratitude to the editors and the reviewers for their valuable time and constructive comments. Their expert insights have significantly strengthened our manuscript. In line with the suggestions provided, we have thoroughly revised the manuscript. We have made every effort to address all the comments comprehensively. Our detailed responses to each of the reviewers' comments are provided below.

==============================================================

 

Response to the Comments Reviewer 3:

 

1. The author did not take about the perfect distance between the receiving and transmitting coils in his design. They talk about horizontal and vertical misalignment only.

Author Response:

We appreciate your positive feedback and insightful suggestions on our revised manuscript. The analysis is focused solely on horizontal and vertical misalignments of the receiving and transmitting coils, without specifying the ideal distance between them for optimal performance. While insights are provided into how misalignments affect coupling and efficiency, the omission of the perfect coil distance leaves a critical parameter unaddressed. This detail is considered essential for practical applications, as power transfer efficiency and system design in wireless power transfer systems are significantly influenced by the optimal distance.

2. There must be curves that show the efficiency and the amount of power transmitted regarding the distance between the receiving and transmitting coils.

Author Response:

Thank you for your encouraging feedback and thoughtful recommendations regarding our updated manuscript. You're correct. For a more comprehensive evaluation of the system's performance, it would be beneficial to include curves that show the efficiency and amount of power transmitted as a function of the distance between the receiving and transmitting coils. These curves would help illustrate how the system performs under varying alignment conditions, providing valuable insights into the system's tolerance to misalignment and its ability to maintain efficiency as the distance between the coils changes. Including such data would enhance the clarity of the system's operational range and performance limits. The graph is modified for more readability.

The efficiency curve with various distance is added in the manuscript. The Figure 3.8 is newly is added which indicates the efficiency curve and the amount of power transmitted regarding the distance between the receiving and transmitting coils.

 

3. In page 4, lines 196-197, R1, R2, R3, and R4 represent what and why they are connected in series, not in parallel?

Author Response:

Thank you for your kind feedback and helpful suggestions on our revised manuscript. In the context of the specified circuit, R1, R2, R3, and R4 generally indicate resistances connected to certain components or segments of the wireless power transfer system. These resistances may include coil resistances, load resistances, or equivalent series resistances of capacitors. They are connected in series to consider the total resistive effects in the power transmission circuit. The series connection ensures that the overall resistance represents the overall effect of all resistive components on power transfer efficiency. Parallel connection would alter the impedance and might not represent the actual power loss across the system accurately.

4. There is a model of 15Kw battery used; for how long is it fully charged using the proposed configuration?

Author Response:

We’re grateful for your constructive comments and valuable suggestions concerning our revised manuscript. The charging time for a 15-kW battery using the proposed configuration depends on the system's power transfer efficiency and the input power provided. With a maximum efficiency of 90% as per the simulation findings, the effective power transfer is:

Assuming the entire battery capacity is 15 kWh, the time to fully charge can be calculated as:

The battery would take approximately 1.1 hours (or about 67 minutes) to fully charge under ideal conditions.

5. There is no comparison curve or table between the proposed technique and the DD model.

Author Response:

We appreciate your encouraging feedback and the practical suggestions you provided on our revised manuscript. The research does not include a direct comparison curve or table between the proposed DDC power pad and the DD model. While the analysis highlights the superior performance of the DDC power pad in terms of misalignment tolerance, coupling coefficient, and efficiency, the absence of a detailed comparative evaluation with the DD model limits a direct performance assessment. Incorporating such comparisons would enhance the study by providing a clearer understanding of the relative advantages of the proposed technique.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report (New Reviewer)

Comments and Suggestions for Authors

Authors have replied to most of the requested comments. I don't have any further comments.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for presenting this interesting work on wirelessly charging EV batteries using the DD circular method. While the proposed method holds promise, there are several areas that require clarification and further investigation before publication. I've outlined my main concerns below:

1. Robustness and Comparison: Please provide a clearer discussion of the robustness of your proposed WPT system. This should include:

→A clear definition of "robustness" in the context of your work, supported by relevant citations.

→A comparison of your system's robustness to existing WPT methods, highlighting the advantages of the DD circular approach.

→Explanation of how your method addresses limitations of previous work in this area.

2. Battery State of Charge (SOC):  Since EV battery internal resistance varies with SOC, it's important to address how this impacts your system's performance. Please provide data on efficiency and power transfer across different battery internal resistance values, reflecting various SOC levels.

3. Ansys Software: Please add a citation for the Ansys software used in your simulations.

4. Coupling Regions: Clarify whether your system is designed to operate effectively in both strong and weak coupling regions. Please comment on its performance, particularly in weak coupling scenarios, as this is crucial for practical WPT applications.

5. Figure 2.2:  This figure needs a more detailed description. Please provide labels, values, and a clear explanation of the purpose of each component in the schematic.

6. Resonance Frequency and Equation 1:Clearly state the resonance frequency of your WPT system.Revisit Equation 1 and ensure it accurately accounts for the influence of internal resistance.

7. Misalignment Definition:  Your definition of misalignment requires further clarification. Please explain how the two thicknesses chosen relate to distance variations and the horizontal/vertical arrangement of the coils.  The connection between the thickness difference and the reported WPT efficiency is currently unclear.

8. Figure 3.3:  For better readability and consistency, please consider presenting Figure 3.3 in the same format as Figure 3.4.

9. Robustness and Frequency: You observe high efficiency at a specific frequency. However, it's crucial to demonstrate how the system maintains efficiency when the distance between coils and the load changes, as these factors affect the coupling constant and resonance frequency. The current efficiency results do not provide sufficient evidence of the system's robustness.

Comments on the Quality of English Language

If needed you can have English Proof reading check. 

Reviewer 2 Report

Comments and Suggestions for Authors

The work presents a DD circular power PAD structure, with the main objective of improving the tolerance to misalignment and reducing electromagnetic emission. Although the subject of the paper is interesting for academia, it does not present innovative results, as this structure and similar results have already been presented in the literature. 

 

1 - In lines 74-76 the authors say: this article presents an 'innovative' power pad structure known as the "DD circular (DDC) power pad" which integrates features from both circular and DD power pads. However, in the literature, especially in reference [18] of the paper, this structure has already been presented. The question for the authors is: What is the main difference in contributions from the current paper for reference [18]?

 

[18] Chowdhury, Muhammad Sifatul Alam, and Xiaodong Liang. "Design and performance evaluation for a new power pad in electric vehicles wireless charging systems." Canadian Journal of Electrical and Computer Engineering 43.3 (2020): 146-156.

 

2 - Introduction of the article is quite similar to that in the reference [18]. Including the main contribution, highlighting the sentence: Inspired by DDQ power pads, this article presents an 'innovative' power pad structure known as the "DD circular (DDC) power pad" which integrates features from both circular and DD power pads. While in [18]: In this article, inspired by DDQ power pads, a new power pad structure by combining circular and DD power pads named “DD circular (DDC) power pad” is designed. The introduction structure is also similar to that in [18].

 

3 -  In this paper it is present results for DDC power pad for coupling coefficient (k) vs vertical misalignment, k vs horizontal misalignment, mutual inductance vs misalignment and efficiency for DDC coil. In [18] a procedure for the performance evaluation of a power pad is presented, comparing the DD, circular and DDC power pads and providing a complete analysis of all the topics mentioned and also including the efficiency comparison for different scenarios.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

Thank You for the opportunity of reading this article. First of all I would like to congratulate you for your work.

General statements about the article:

The article presents a well-structured approach to the design and simulation of an Inductive Power Transfer system with a focus on a new power pad for electric vehicles (EV). The content is relevant, well written and emphasizes the importance of inductive power transmission systems in electric vehicle applications.

The style of writing needs to be improved, generally.The language is generally clear, but some areas require refining for better readability. All abbreviations must be explained, even the commonly known ones. Authors should use technical terms consistently: (sometimes "inductive power transfer" is used and sometimes the abbreviation IPT).

Citations are relevant, but several references in the introduction do not have full source details, especially with URLs. Most of the references are new, but citing some foundational references would help raise the quality of the article.

Diagrams and figures could be more clearly labeled. (Figure 3.7 could contain a clearer specification of the conditions under which maximum efficiency is achieved.)

In conclusion, authors should look critically at the contribution of the paper and provide suggestions for improvements in future research.

In this research, the student version of Ansys Maxwell 3D (Ansys 2024 R2) software was used, which limits certain functionalities, which could potentially affect the obtained results.

It should be emphasized in what direction future research should go and suggest future work with unrestricted (less constrained) software for validation of results.

Comments on the Quality of English Language

The style of writing needs to be improved, generally.The language is generally clear, but some areas require refining for better readability.