Modeling an Energy Router with an Energy Storage Device for Connecting Electric Vehicle Charging Stations and Sustainable Development of Power Supply Systems

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Based on my review, please find the questions that would enhance the quality of the manuscript:

1. Does your optimization framework presuppose a specific hardware architecture, such as the "Energy Router" or "Solid State Transformer" concepts mentioned in sources [37] and [38]? What are the computational requirements for real-time implementation?
2. Your work focuses on a single charging station. How does your model account for broader grid impacts, such as the power quality and harmonic distortions discussed in sources [18] and [19], and how might it be scaled to a network of stations?

1. What is the main question addressed by the research? 

The research aims to test the efficiency of a proposed automatic regulation system for an energy router that incorporates an energy storage device. The main question is how this system impacts voltage stability and power quality (specifically harmonic distortion) in a power supply system connected to electric vehicle charging stations.

2. Do you consider the topic original or relevant to the field? Does it address a specific gap in the field? 

The topic is highly relevant, as the study addresses the challenges posed by the widespread adoption of electric vehicles and their charging stations on power grid stability. The paper identifies a specific gap: the need for unique automatic voltage regulation systems to manage power flows and improve power quality when using energy routers as interfaces for charging stations. The novelty lies in the development and simulation of this specific regulator model and its application to improve voltage and power quality. 

3. What does it add to the subject area compared with other published material? 

This study contributes a modified model of a voltage regulator for an energy router inverter, which includes an algorithm to stabilize both DC and AC voltage. It presents simulation models and experimental results demonstrating that applying this proposed regulator with an energy storage device can reduce voltage drops during the connection of high-power loads, maintain voltage near the nominal value during emergencies like short circuits, significantly improve power quality by reducing the total harmonic distortion of voltage. 

4. What specific improvements should the authors consider regarding the methodology? 

The methodology is based on simulation in MATLAB. The authors themselves note a limitation in their results, stating that "The PID controller must be reconfigured to enhance sensitivity." This suggests the control parameters are not fully optimized. Furthermore, the paper concludes that complete suppression of high harmonics would require active filters, and that further research is needed to design and test systems that incorporate them. The authors should consider addressing the PID controller's sensitivity and discussing the potential integration of active filters more thoroughly.

5. Are the conclusions consistent with the evidence and arguments presented and do they address the main question posed? 

Yes, the conclusions are consistent with the presented evidence. The main question regarding the system's efficiency is addressed directly. Figures show the regulator maintaining voltage near the nominal value during a high-power load connection (Figure 10) and a short-circuit (Figure 8). The data also shows a reduction in total harmonic distortion to 0.06% (Figure 13). The authors conclude the system reduces voltage dips and improves power quality. This is directly supported by the simulation results shown in the figures and described in the text.

6. Are the references appropriate? 

The references appear appropriate and current. Many citations are from 2023, 2024, and 2025, indicating that the authors are engaging with recent literature. The sources include reputable journals and conferences in the fields of energy, power electronics, and transportation, which are directly relevant to the manuscript's topic.

7. Any additional comments on the tables and figures. 

The figures are generally clear and support the paper's claims. The use of numbered curves in Figures 10-12 to represent different operating scenarios is helpful and well-explained in the text. However, Figure 12 reveals that in two of the three scenarios, key regulator signals remain "virtually unchanged," leading to the authors' own critique that the PID controller needs reconfiguration for better sensitivity. This is a crucial point that weakens the presented results for those scenarios and should be addressed in the revisions. There are no tables in the provided material to review.

Author Response

We thank the distinguished reviewer for valuable comments.

Based on my review, please find the questions that would enhance the quality of the manuscript:

1. Does your optimization framework presuppose a specific hardware architecture, such as the "Energy Router" or "Solid State Transformer" concepts mentioned in sources [37] and [38]? What are the computational requirements for real-time implementation?
2. Your work focuses on a single charging station. How does your model account for broader grid impacts, such as the power quality and harmonic distortions discussed in sources [18] and [19], and how might it be scaled to a network of stations?

Question 1 is discussed in the article: the concept of a solid-state transformer is used. Question 2: Three charging stations were considered in the study; when using a network of stations, they can be divided into groups and connected to individual energy routers. The issue of power quality is discussed in the article.

Reviewer 2 Report

Comments and Suggestions for Authors

The paper tackles a highly relevant and contemporary issue, the integration of energy routers with energy storage systems (ESS) in electric vehicle (EV) charging infrastructures to enhance voltage stability and power quality.

Its main strength lies in the practical modeling conducted in MATLAB/Simulink and the quantitative evaluation of voltage harmonics and system dynamics under various fault and load scenarios.

Nonetheless, the manuscript would benefit from improved structural organization, stronger quantitative analysis, and a more comprehensive comparison with recent related studies.

Comments:

1. The paper should clearly highlight the distinguishing features of the proposed regulator compared to conventional PI/PID controllers operating in the d–q reference frame. In addition, it should reference recent studies from 2023–2025 that have introduced comparable control approaches, such as neural-network-based or adaptive energy-router regulation techniques.
2. Concerning figures 2–6 are complex Simulink screenshots; you may simplify or redraw them clearly.
3. Please try to verify all symbols in equations appear in figures (e.g.,V_dc , ).
4. Equation (2) for PID transfer function is written inconsistently. You must correct notation and clearly define .
5. Several grammatical issues and typos exist in the manuscript (eg in the figure2: thansformer, invertor).
6. Please ensure that both axis titles (Y-axis and X-axis) use consistent font size and style for readability. You can see the template.(eg: Time(s) below figure.)
7. Please improve figure presentation.
8. In the Conclusions, the numbering of the listed points is inconsistent,(eg the first point is repeated as “1. 1.” at the beginning). Please revise and correct the numbering format in all this section to maintain clarity and consistency.
9. The “Author Contributions” section repeats names excessively; condense and align with journal template.

Comments for author File: Comments.pdf

Author Response

We thank the distinguished reviewer for valuable comments.

1. The paper should clearly highlight the distinguishing features of the proposed regulator compared to conventional PI/PID controllers operating in the d–q reference frame. In addition, it should reference recent studies from 2023–2025 that have introduced comparable control approaches, such as neural-network-based or adaptive energy-router regulation techniques.

Corrected. Information added to sections 2 and 3.

2. Concerning figures 2–6 are complex Simulink screenshots; you may simplify or redraw them clearly.

Figures 2-6 were drawn in Visio. Remade.

3. Please try to verify all symbols in equations appear in figures (e.g.,V_dc , ).

Corrected

4. Equation (2) for PID transfer function is written inconsistently. You must correct notation and clearly define .

Corrected. Explanations added to equations and Fig. 5 corrected.

5. Several grammatical issues and typos exist in the manuscript (eg in the figure2: thansformer, invertor).

Corrected.

6. Please ensure that both axis titles (Y-axis and X-axis) use consistent font size and style for readability. You can see the template.(eg: Time(s) below figure.)

Corrected.

7. Please improve figure presentation.

Corrected.

8. In the Conclusions, the numbering of the listed points is inconsistent,(eg the first point is repeated as “1. 1.” at the beginning). Please revise and correct the numbering format in all this section to maintain clarity and consistency.

Corrected.

9. The “Author Contributions” section repeats names excessively; condense and align with journal template.

Corrected.