Dynamic Control of Integrated Wind Farm Battery Energy Storage Systems for Grid Connection

Round 1

Reviewer 1 Report

Dear Authors,

Thank You for the opportunity of reading this article.

 

General statements

-> Article concerns dynamic control of integrated wind farm ESS to develop a control system based on MPC combined with a  battery ESS capable of mitigating problems of wind power variability and intermittency. The aim of the research is actual and desirable.

-> The article suite to Sustainability journal scope

-> Abstract is adequate to article content

-> Keywords suite to article content

-> Article is based on 5 sections. The organization of the sections is correct.

-> The results of the article are based on simulation without real verification.

-> The simulation model was based on wind farm BESS for grid connections in South Africa.

-> The novelty of the proposed solution is indicated in lines 99-105

-> The article is based on 31 literature positions.

 

Elements that require major revision

#1 Literature background

Please extend the literature background with at least 5 more literature positions from journals or conferences from the last 2-3 years. Because now a background in introduction discusses deeply only 7 positions (ref 7, 10-16). This must be extended.

 

#2 Article organization description

Please add at the end of the introduction a short paragraph that would describe the article's organization. I mean “Section 2 concerns …, Section 3 presents …” etc.

 

#3

The results in section 4 are clear. But there is no discussion of them. Even that title of chapter 4 includes “ Results and Discussion” in fact presents only results. Thus please include a separate section with a discussion. Then please discuss the results. Please compare them to similar results from the literature to highlight the significance of the proposed solution.

 

#4 chapter numbering

Conclusions should have a number as a section.

#5 Extend the conclusions

Please extend the conclusion with future research directions.

 

 

Technical issues:

Generally, the quality of the presentation must be improved:

->Formatting of equations.

-> caption of tables should be before tables

-> size of text included in figures 7, 8, and all next, should be bigger. Now it’s hard to read it and analyze the information from figures.

-> please bac to temple because captions of figures and tables should be formatted in another form.

Author Response

Dear Reviewer

Kindly find attached rebuttal letter.

Thanks

Mandisi Gwabavu

 

Author Response File: Author Response.pdf

Reviewer 2 Report

In general, the paper is interesting, even though several clarifications should be added in the paper.

 

All the following indicated aspects should be clarified and better explained in the manuscript.

 

Introduction / Literature review

1. The authors should better highlight the innovative aspects of their work in the manuscript.
2. For the sake of readability, at the end of Section 1 the authors should describe how the paper is structured (maybe the outline can be moved from the end of section 2).

 

 

Methodology

3. The description of the proposed methodology could be deeply improved. First, it could be better to insert at the beginning of the second section (Section 2) an outline about the system scheme/architecture (how many components, the aim of each, etc.); here, a high-level diagram/scheme could also help reader following the whole description.
4. All the used variable in all the formula should report the unit.
5. The model of the battery storage is not clear. It is generally modelled as a first order buffer. The author should comment the choice of their model, compared with the other schem defined in the related literature (e.g., https://doi.org/10.3390/en12071231, https://doi.org/10.1109/SMC.2019.8913892, documents that could be cited in the text). The Authors should comment this point.
6. How do the authors take care of the uncertainty parameters? Related literature identifies stochastic and robust optimization approach to deal with the uncertainty of renewables. The author should comment the choice of their framework, compared with the other robust frameworks defined in the related literature (e.g., https://doi.org/10.1109/TASE.2020.2986269, https://doi.org/10.1016/j.renene.2020.02.027, documents that could be referenced in the text).

 

Problem formulation

7. The author should clearly characterize the overall on-line problem (7)-(21) that they intend to solve. What type of decision variables (i.e. integer, real, etc) and how many? How many constraints (bounding, inequality, equality)?

 

Results

8. The presentation of simulations could be improved: where do the presented data come from?
9. To show the worth of the proposed study, the authors could add some comparison with the performances of other state of the art dashboard of indicators.

 

Conclusions

10. Conclusions needs to be extended to present further implications for future research and many managerial insights based on the results of the study, as well as limitations.

 

 

Minor

11. Mainly the English should be improved and the paper should be carefully rechecked including figures
12. The authors should check that all the used acronyms are explained the first time they are used.
13. The editing should be improved: all the equations appear as pictures.

Author Response

Dear Reviewer

Kindly find attached rebuttal letter.

Thanks

Mandisi Gwabavu

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper studies the dynamic control of integrated wind farm battery storage systems for efficient grid connection. The used method is based on an active reference generator and model predictive control. Although the considered problem is interesting and important, the paper's writing and style do not meet the standards of a journal manuscript. It is full of grammatical or syntactical mistakes along with low-quality figures and poorly formulated equations. In the reviewer's opinion, the paper needs a major revision before being suitable for a technical review. For reference, here are some detailed review comments:

 

- Introduction needs to be improved in several aspects. One can notice the repetitive information. Please read carefully and reduce the content by removing the unnecessary repetitive information. For instance, the problem of inherent variable nature of wind energy in terms of frequency/voltage imbalances, is mentioned for several times at the beginning of different paragraphs. Also, several sentences are not clear or technically poor-written. For instance,

 

What do you mean by "Wind power integration is primarily a problem, including power interference, ramp speed and a decrease in wind output."? You probably meant "wind power output"? Please be precise.

 

Another example is "The time change is to store extra wind power during low demand times and is ready to ship power during high demand periods into the grid". Although the overall meaning could be inferred from the context, this sentence sounds wrong! What do you mean by "time change"?

 

In addition, here are a few sentences as examples (among many!) that are clumsy, not clear, and/or grammatically poorly written:

 

"The production smoothing in the plant decreases the demand for electricity quality and system auxiliary services [12]. "

"Further BESS can mitigate congestion, postpone, or prevent improvements to transmission and [10], [11]."

"In high voltage, high and medium voltage grids, wind turbines must also be enabled to engage in static and dynamic grid support."

"Dynamic grid support avoids the unwanted turn-off of major power supplies and, when component failures occur on the maximum and maximum voltage grids, the resulting grid collapses"

"Dynamic grid support is not required when generating installations that feed into the low-voltage grid."

"Dynamic management of interconnected grid-connected wind farm storage systems would therefore be necessary to ensure the mitigation of variable wind farm output variability and to maintain grid power stability."

 

Lastly, the paper lacks a sufficient review of the literature in terms of the methodology. The application of MPC in power systems and microgrids is an active area of research and some references need to be reviewed and cited. For instance, the following papers could be considered:

 

*Jiefeng Hu, Yinghao Shan, Josep M. Guerrero, Adrian Ioinovici, Ka Wing Chan, Jose Rodriguez, Model predictive control of microgrids – An overview, Renewable and Sustainable Energy Reviews, Volume 136, 2021.

*Feng Zhang, Aihui Fu, Lei Ding, Qiuwei Wu, MPC based control strategy for battery energy storage station in a grid with high photovoltaic power penetration, International Journal of Electrical Power & Energy Systems, Volume 115, 2020.

*Weipeng Liu, Yutian Liu, Hierarchical model predictive control of wind farm with energy storage system for frequency regulation during black-start, International Journal of Electrical Power & Energy Systems, Volume 119, 2020.

*Rodríguez del Nozal, Á.; Gutiérrez Reina, D.; Alvarado-Barrios, L.; Tapia, A.; Escaño, J.M. A MPC Strategy for the Optimal Management of Microgrids Based on Evolutionary Optimization. Electronics 2019, 8, 1371.

*Jadidi, S.; Badihi, H.; Zhang, Y. Passive Fault-Tolerant Control Strategies for Power Converter in a Hybrid Microgrid. Energies 2020.

 

-Equations (1-5), their used notations and paragraphs after the equations all need to be improved and rewritten by using unified notations. Please use a professional equation style with consistent font properties throughout the paper.

 

-In addition, figures are of very low quality with vague details in some cases.

Author Response

Dear Reviewer

Kindly find attached rebuttal letter.

Thanks

Mandisi Gwabavu

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear Authors,

Thank You for including my comments. In this, for I recommend Your article to be published.

With kind regards,

Dr. Michal Jasinski

Reviewer 2 Report

The Authors’ reply seems to address the raised questions. The updated version of manuscript is much better than the previous one. In the opinion of this Reviewer the manuscript deserves to be published.