VSG Control for Cascaded Three-Phase Bridge Based Battery Inverter
Round 1
Reviewer 1 Report
The paper titled "VSG Control for Cascaded Three-phase Bridge Based Battery Inverter" presents a cascaded three-phase bridge inverter topology and explores its application in a microgrid system. The paper also introduces a new modulation strategy called CPSD-PWM and discusses the VSG control strategy for achieving accurate control of voltage and frequency. The experimental results verify the effectiveness of the proposed strategies. However, there are several areas where the paper can be improved:
1) Clarify the research objective: The paper lacks a clear statement of the research objective or problem statement. It would be beneficial to explicitly state what problem the proposed cascaded three-phase bridge inverter and control strategies aim to solve. This will help readers understand the significance and relevance of the research.
2) Provide more context and motivation: The introduction should provide a better explanation of the background and motivation for the research. Why is there a need for improved balance in three-phase output? What are the current limitations of traditional cascaded H-bridge inverters? Providing more context will help readers understand the importance of the proposed solutions.
3) Expand on the mathematical model: The mathematical model of the cascaded three-phase bridge inverter is briefly mentioned but not adequately explained. It would be beneficial to provide more details and equations describing the model. This will help readers understand the underlying principles and assumptions of the proposed system.
4) Provide a comparison with existing solutions: The paper mentions that the proposed multilevel inverter and modulation strategy are improvements over traditional approaches. However, a detailed comparison with existing solutions, including their advantages and limitations, is missing. Providing such a comparison will strengthen the paper's contribution and help readers understand the novelty of the proposed techniques.
5) Discuss limitations and future directions: The paper lacks a discussion on the limitations of the proposed methods and suggestions for future research directions. Including this information will add depth to the paper and indicate potential areas for further improvement or investigation.
Minor corrections are required.
Author Response
Please see the file.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript proposes a cascaded three-phase bridge inverter topology for the battery system used in electric vehicles. The proposed methodology is based on the CPSD-PWM modulation and VSG control strategies. The simulations and experimental validation for the cascaded three-phase bridge inverter show promising results.
Below are the comments that should be addressed in the revised manuscript:
1. The manuscript requires additional proofreading.
2. All abbreviations should be defined when first mentioned, both in the Abstract and in the main text.
3. The authors should provide a paragraph describing the manuscript’s structure at the end of the Introduction section.
4. The literature review is too short. The reference list contains only 12 references. The authors should extend the literature review by recent relevant journal papers.
5. The authors should provide quantitative metrics for the evaluation of the obtained performance.
6. The authors should also provide an additional comparison of the proposed method with the state-of-the-art approaches.
7. The discussion of the results should be extended.
8. In the Conclusions section, the authors should state the limitations of the presented study.
9. The authors should also elaborate on the directions for future research in the Conclusions section.
The manuscript requires additional proofreading.
Author Response
Please see the file.
Author Response File: Author Response.docx
Reviewer 3 Report
This paper combines the CPSD-PWM control and VSG control for a two-stage three-phase bridge inverter, where the CPSD-PWM control can output less harmonics and improve the balance of the three-phase output; and VSG can improve the stability of primary frequency regulation for the multilevel microgrid inverter. Simulation and experiment results show both of the frequency and voltage can be kept steady when there is a load change under the combined control, which can be used for supporting the grid. This research about the control of the energy storage is the hot-spot in this domain. However, there are several aspects that need to be explained further:
1. It is mentioned ‘the CPSD-PWM is proposed in this paper’, please make sure it is indeed proposed by the research group. If the control is not firstly proposed, please clarify which part is the novel research, the control strategy or the topology, etc. Or the combination of the CPSD-PWM and VSG controls forms the new control?
2. Simulation and experiment results show the advantages of the VSG control. However, it is better compare them with results without VSG control, which will show more clearly the advantages of the control.
3. It is not show how to get the control parameters of VSG.
4. There are some small errors in the paper, such as ‘sine wase ’ in the 2nd line of page 16, ‘220v’ in the 24th line of the same page, and ‘5uF’ in Table 2. Further editing is required.
Minor editing is required.
Author Response
Please see the file.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors have revised the paper. The paper can be accepted in the present form.
