Study of Hybrid Transmission HVAC/HVDC by Particle Swarm Optimization (PSO)
Round 1
Reviewer 1 Report
The topic addressed “Study of Hybird Trasmission HVAS/HVDC by Particel Swarm Optimzation (PSO) is potentially interesting, however, there are some issues that should be addressed by the authors:
1-The Introduction" sections can be made much more impressive by highlighting your contributions. The contribution of the study should be explained simply and clearly. The authors should enhance the introduction with current work about energy (also renewable energy) systems and HVDC techniques (LCC and VSC) to improve the research background, for example country specific researches which has close developing structure to Indonesia can be introduced: “A life-cycle cost analysis of High Voltage Direct Current utilization for solar energy systems: The case study in Turkey”; “High voltage direct current systems through submarine cables for offshore wind farms: A life-cycle cost analysis with voltage source converters for bulk power transmission”.
2- I recommend a proof reading to authors, there are some typo, abbreviation, and sentence structural errors that should be revised. It will be better to enlarge Figure 1. Please indicate the name of the equations in the text, (i.e., according to Eq. 3,…, 5…)
3- Please, explicitly explain both materials and methods. What are you doing, why like that, what are the advantages of this methods, and give the theoretical background of the methodology. Please, explicitly explain section 3.1, Figure 7-12. Table 1’s caption: “This is a table. Tables should be placed in the main text near to the first time they are” should be revised. In line 266 p. 12: I thik Figure 2 shoud be Figure 13, please revise it.
4- Does the conclusion answer all the questions posed at the beginning of the paper (expressed in objectives and hypotheses)? Please complete it and also correct it. The conclusion needs to be supplemented. Conclusion section should be rearranged. According to the topic of the paper, the authors may propose some interesting problems as future work in the conclusion.
5- All sections should be enlarged with connections sentences. In its current form the paper more looks like an experiment supplement. The empty spaces should be fulfilled with convenient explanations including fluent and understandable sentences.
This study may be proposed for publication if it is addressed in the specified problems.
Author Response
Response to Reviewer 1 Comments
Point 1: The Introduction" sections can be made much more impressive by highlighting your contributions. The contribution of the study should be explained simply and clearly. The authors should enhance the introduction with current work about energy (also renewable energy) systems and HVDC techniques (LCC and VSC) to improve the research background, for example country specific researches which has close developing structure to Indonesia can be introduced: “A life-cycle cost analysis of High Voltage Direct Current utilization for solar energy systems: The case study in Turkey”; “High voltage direct current systems through submarine cables for offshore wind farms: A life-cycle cost analysis with voltage source converters for bulk power transmission”.
Response 1: Thank you for the correction. The authors have added in line 34-40
Point 2: I recommend a proof reading to authors, there are some typo, abbreviation, and sentence structural errors that should be revised. It will be better to enlarge Figure 1. Please indicate the name of the equations in the text, (i.e., according to Eq. 3,…, 5…)
Response 2: Thank you for the correction. The author has done proofreading, and Figure 1 has enlarged, then mentioned the name of the equation in the text
Point 3: Please, explicitly explain both materials and methods. What are you doing, why like that, what are the advantages of this methods, and give the theoretical background of the methodology. Please, explicitly explain section 3.1, Figure 7-12. Table 1’s caption: “This is a table. Tables should be placed in the main text near to the first time they are” should be revised. In line 266 p. 12: I thik Figure 2 shoud be Figure 13, please revise it.
Response 3: Thank you for the correction. The author has added and corrected the title in Table 2 (line 346)
Point 4: Does the conclusion answer all the questions posed at the beginning of the paper (expressed in objectives and hypotheses)? Please complete it and also correct it. The conclusion needs to be supplemented. Conclusion section should be rearranged. According to the topic of the paper, the authors may propose some interesting problems as future work in the conclusion.
Response 4: The author has added information in conclusion
Point 5: All sections should be enlarged with connections sentences. In its current form the paper more looks like an experiment supplement. The empty spaces should be fulfilled with convenient explanations including fluent and understandable sentences.
Response 5: The author has added connection sentences.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Study of Hybrid Transmission HVAC/HVDC by Particle Swarm Optimization (PSO)
(Review Comments)
1. The abstract of the manuscript can be improved. The authors are advised to critical points relevant HVDC networks in their abstract. Moreover, the authors are advised to add experimental results in the form of percentage improvement/efficiency (as like presented in Table 1).
2. Modern-day research is emphasizing on the Voltage Source Convertor (VSC) in HVDC technology, Therefore, also add some literature review regarding Voltage Source Convertor (VSC) in the 2nd Paragraph of introduction section. Also compare the proficiencies of Line Commutated Convertor (LCC) and Voltage Source Convertor (VSC).
3. Line No. 43. “One of the problems is the transmission system will experience a power loss along the line due to the length of the conductor.” This line is quiet generic. Elucidate the reasons of powers losses which occurs in HVAC. Also give a thorough comparison of the advantages and disadvantages of HVAC and HVDC.
4. The literature regarding Hybrid HVAC-HVDC is quite small in this manuscript. The authors are advised to more discussion regarding modern day MTDC systems in their manuscript to make their article worth reading.
5. The literature review is not updated as per latest research of the relevant field. The authors are advised to add some recent research in the manuscript, such as DC Voltage Droop Control, Frequency support, Optimal Power Flow, Adaptive droop control, Reactive power support etc.
6. The literature review section lacks the discussion of optimization algorithms used in similar case studies. The authors have used Particle Swarm Optimization Algorithm (PSO) in their case study. Please elucidate the reason of preferring PSO over other optimization algorithms, despite that other more robust algorithms could have been used for this purpose. The authors are also advised to extend the discussion and add some literature regarding other optimization algorithms in literature review section also.
7. Summarize the discussion of Section No. 1 Introduction in a nutshell in the form of bullets at the end of section. This would make this article make this article worth reading.
8. “Power flow control” is one of the main advantage and capability of HVDC networks, which is not available in HVAC networks. Discus the aforementioned point in Section 2.2.
9. The authors have used Particle Swarm Optimization Algorithm (PSO) their research work. However, the manuscript lacks any discussion and details about it. The authors are advised to mention all tuning parameters of the algorithm used in simulation and its relevant details in a separate sub-section.
10. The methodology lacks novelty, since the Particle Swarm Optimization Algorithm (PSO) is quiet and old algorithm which have been used is power system studies many times. Therefore, the authors are advised to implement modern-day hybrid optimization algorithms in their case study. A comparative analysis between the experimental results of Hybrid and PSO algorithms will surely enhance the publicity of this article.
11. The Section no. 4 of the discussion only represents the experimental results of the simulation. The theoretical discussion is supposed to be the core theme of this section, which is mission. Therefore, add some theoretical discussion relevant to the experimental results in this section.
12. The Section no. 5 of conclusion lacks critical analysis, which should be necessarily added to make this article worth reading.
13. The paper is well written and well presented. However, the authors entirely focused on the system running in “normal conditions” and have not critically utilized and presented the proficiencies of HVDC systems in their case study. The authors are advised to add a separate portion of “Contingency Analysis”, since the case under study in quite vast and consists of 72 buses. Therefore, the operational strategy of the Hybrid HVAC-HVDC systems can become quite troublesome in contingency conditions when the system is prone to a sudden outage of converters and various transmission equipment.
Author Response
Response to Reviewer 2 Comments
Point 1: The abstract of the manuscript can be improved. The authors are advised to critical points relevant HVDC networks in their abstract. Moreover, the authors are advised to add experimental results in the form of percentage improvement/efficiency (as like presented in Table 1).
Response 1: Thank you for the correction. The author has added information in abstract.
Point 2: Modern-day research is emphasizing on the Voltage Source Convertor (VSC) in HVDC technology, Therefore, also add some literature review regarding Voltage Source Convertor (VSC) in the 2nd Paragraph of introduction section. Also compare the proficiencies of Line Commutated Convertor (LCC) and Voltage Source Convertor (VSC).
Response 2: Thank you for the correction. The author has added information on VSC, comparing the proficiencies of Line Commutated Converter (LCC) and Voltage Source Converter (VSC) in the introduction section.
Point 3: Line No. 43. “One of the problems is the transmission system will experience a power loss along the line due to the length of the conductor.” This line is quiet generic. Elucidate the reasons of powers losses which occurs in HVAC. Also give a thorough comparison of the advantages and disadvantages of HVAC and HVDC.
Response 3: Thank you for the correction. The author has revised it and added a comparison of HVAC and HVDC
Point 4: Line No. 43. The literature regarding Hybrid HVAC-HVDC is quite small in this manuscript. The authors are advised to more discussion regarding modern day MTDC systems in their manuscript to make their article worth reading.
Response 4: Thank you for the information. The author has added literature on Hybrid HVAC-HVDC and MTDC systems.
Point 5: The literature review is not updated as per latest research of the relevant field. The authors are advised to add some recent research in the manuscript, such as DC Voltage Droop Control, Frequency support, Optimal Power Flow, Adaptive droop control, Reactive power support etc.
Response 5: The author has added some literature.
Point 6: The literature review section lacks the discussion of optimization algorithms used in similar case studies. The authors have used Particle Swarm Optimization Algorithm (PSO) in their case study. Please elucidate the reason of preferring PSO over other optimization algorithms, despite that other more robust algorithms could have been used for this purpose. The authors are also advised to extend the discussion and add some literature regarding other optimization algorithms in literature review section also.
Response 6: Thank you for the correction. The author has added some literature about PSO.
Point 7: Summarize the discussion of Section No. 1 Introduction in a nutshell in the form of bullets at the end of section. This would make this article make this article worth reading.
Response 7: Thank you for the suggestion. The author has already revised it.
Point 8: Power flow control” is one of the main advantage and capability of HVDC networks, which is not available in HVAC networks. Discus the aforementioned point in Section 2.2.
Response 8: Thank you for the suggestion. The author has added information power flow control in section 2.2.
Point 9: The authors have used Particle Swarm Optimization Algorithm (PSO) their research work. However, the manuscript lacks any discussion and details about it. The authors are advised to mention all tuning parameters of the algorithm used in simulation and its relevant details in a separate sub-section.
Response 9: Thank you for the suggestion. The author has added some literature about PSO.
Point 10: The methodology lacks novelty, since the Particle Swarm Optimization Algorithm (PSO) is quiet and old algorithm which have been used is power system studies many times. Therefore, the authors are advised to implement modern-day hybrid optimization algorithms in their case study. A comparative analysis between the experimental results of Hybrid and PSO algorithms will surely enhance the publicity of this article.
Response 10: The author has revised it and added novelty in the introduction section
Point 11: The Section no. 4 of the discussion only represents the experimental results of the simulation. The theoretical discussion is supposed to be the core theme of this section, which is mission. Therefore, add some theoretical discussion relevant to the experimental results in this section.
Response 11: The author has added theoretical discussion in the discussion section
Point 12: The Section no. 5 of conclusion lacks critical analysis, which should be necessarily added to make this article worth reading.
Response 12: The author has revised it and added information critical analysis in conclusion section
Point 13: The paper is well written and well presented. However, the authors entirely focused on the system running in “normal conditions” and have not critically utilized and presented the proficiencies of HVDC systems in their case study. The authors are advised to add a separate portion of “Contingency Analysis”, since the case under study in quite vast and consists of 72 buses. Therefore, the operational strategy of the Hybrid HVAC-HVDC systems can become quite troublesome in contingency conditions when the system is prone to a sudden outage of converters and various transmission equipment.
Response 13: Thank you for the suggestion regarding the reviewer's advice to add a separate portion of “Contingency Analysis,” We think it is a really interesting idea to develop in our future work, with deeper analysis and contains more complex variables related. However, in this paper, we focused on simulation in normal conditions.
Author Response File: Author Response.docx
Reviewer 3 Report
1. Grammatical errors, so a proof read required.
2. Reference papers are less, if possible five more reference paper can be added.
Author Response
Response to Reviewer 3 Comments
Point 1: Grammatical errors, so a proof read required.
Response 1: Thank you for the correction. The author has done proofreading
Point 2: Reference papers are less, if possible five more reference paper can be added.
Response 2: Thank you for the suggestion. The author has added five more reference papers.
Author Response File: Author Response.docx
Reviewer 4 Report
This paper present a case study to show the benefit of using HVDC line by using a commercial software (not clearly mentioned). It is not a new computational method development or modification of existing model. It is rather a simple exercise of using commercial software.
To my judgement the merit is too low for a journal publication. I can not recommend this paper for publication in its current form.
Author Response
Response to Reviewer 4 Comments
Point 1: This paper present a case study to show the benefit of using HVDC line by using a commercial software (not clearly mentioned). It is not a new computational method development or modification of existing model. It is rather a simple exercise of using commercial software.
To my judgement the merit is too low for a journal publication. I can not recommend this paper for publication in its current form
Response 1: Thank you for the correction and for the suggestion .
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Now the paper is more appropriate to be published in Energies Journal.
Author Response
The author thanks a lot.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
REVIEWER COMMENTS
(2nd ROUND)
1. Line 42, 43, 44. “There are three main techniques that can be used for converting AC to DC and vice versa: the line commutated converter (LCC) [4], the voltage source converter (VSC) [5, 6], and multi-terminal direct current (MTDC)” [7].
MTDC is not a technique, it is basically a combination of multiple terminal stations each with their own converter connected by the HVDC transmission line network. Whereas LCC and VSC are the two main technologies that are being widely used in high voltage direct current (HVDC) power transmission.
2. The authors have not addressed the 4th point of previous review comments quite effectively. They merely added and relied on one or two sentence to address it. The authors are once again advised that literature should comprehensively include the discussion regarding “hybrid HVDC grids & MTDC networks” by citing different modern technological schemes been used in hybrid systems. Hybrid HVDC system is the core scheme and selling point of this article, and it should be addressed properly.
3. The authors have merely submitted the positive compliance of 5th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The literature still lacks the latest research of the relevant field. The authors are once again advised to add some recent research in the manuscript, such as DC Voltage Droop Control, Frequency support, Optimal Power Flow, Adaptive droop control, Reactive power support etc.
4. The authors have merely submitted the positive compliance of 6th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The authors are once again advised to elucidate the reason of preferring PSO over other optimization algorithms, despite that other more robust algorithms could have been used for this purpose. The authors are also advised to extend the discussion and add some literature regarding other optimization algorithms in literature review section
5. The authors have merely submitted the positive compliance of 7th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The authors are once again advised to Summarize the discussion of Section No. 1 Introduction in a nutshell in the form of bullets at the end of section.
6. Following the suggestions of 8th point of previous review, the authors are advised to cite some more references and literature regarding “Power Flow Control” in Section 2.2 for more improvement in paper.
7. The authors have not properly addressed the 9th point of the previous review in the paper as suggested in preview review comments. The authors have only discussed the working of PSO algorithm and ignored the suggestions of mentioning tuning parameters of the algorithm used in simulation. The authors are once again advised to submit the manuscript with full compliance.
8. The authors have merely submitted the positive compliance of 10th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The authors are once again advised to implement modern-day hybrid optimization algorithms in their case study and perform a comparative analysis between the experimental results of Hybrid algorithms and PSO algorithm.
9. The critical discussion added at the end of Section no. 5 conclusion is not enough. It can be made more comprehensive and productive and conclusive.
Author Response
- Line 42, 43, 44. “There are three main techniques that can be used for converting AC to DC and vice versa: the line commutated converter (LCC) [4], the voltage source converter (VSC) [5, 6], and multi-terminal direct current (MTDC)” [7].
MTDC is not a technique, it is basically a combination of multiple terminal stations each with their own converter connected by the HVDC transmission line network. Whereas LCC and VSC are the two main technologies that are being widely used in high voltage direct current (HVDC) power transmission.
Response 1: Thank you for the correction. The author has revised it (Line 42).
- The authors have not addressed the 4th point of previous review comments quite effectively. They merely added and relied on one or two sentence to address it. The authors are once again advised that literature should comprehensively include the discussion regarding “hybrid HVDC grids & MTDC networks” by citing different modern technological schemes been used in hybrid systems. Hybrid HVDC system is the core scheme and selling point of this article, and it should be addressed properly.
Response 2: Thank you for the correction. The author has revised it (Line 53-64).
- The authors have merely submitted the positive compliance of 5th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The literature still lacks the latest research of the relevant field. The authors are once again advised to add some recent research in the manuscript, such as DC Voltage Droop Control, Frequency support, Optimal Power Flow, Adaptive droop control, Reactive power support etc.
Response 3: The author has revised it (Line 94-111).
- The authors have merely submitted the positive compliance of 6th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The authors are once again advised to elucidate the reason of preferring PSO over other optimization algorithms, despite that other more robust algorithms could have been used for this purpose. The authors are also advised to extend the discussion and add some literature regarding other optimization algorithms in literature review section
Response 4: The author has revised it (Line 205-219).
- The authors have merely submitted the positive compliance of 7th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The authors are once again advised to Summarize the discussion of Section No. 1 Introduction in a nutshell in the form of bullets at the end of section.
Response 5: The author has revised it (Line 111-125).
- Following the suggestions of 8th point of previous review, the authors are advised to cite some more references and literature regarding “Power Flow Control” in Section 2.2 for more improvement in paper.
Response 6: The author has added some literature (Line 192-204).
- The authors have not properly addressed the 9th point of the previous review in the paper as suggested in preview review comments. The authors have only discussed the working of PSO algorithm and ignored the suggestions of mentioning tuning parameters of the algorithm used in simulation. The authors are once again advised to submit the manuscript with full compliance.
Response 7: The author has revised it (Line 219-250).
- The authors have merely submitted the positive compliance of 10th point of the previous review in the paper, but unfortunately have not addressed them the way as suggested in preview review comments. The authors are once again advised to implement modern-day hybrid optimization algorithms in their case study and perform a comparative analysis between the experimental results of Hybrid algorithms and PSO algorithm.
Response 8: The author has revised it (Line 112-125).
- The critical discussion added at the end of Section no. 5 conclusion is not enough. It can be made more comprehensive and productive and conclusive.
Response 9: The author has added a discussion section (Line 461-464).
Author Response File: Author Response.pdf
Reviewer 4 Report
I am not convince. My decision is still to reject.
Author Response
Thank you for the suggestion.
Author Response File: Author Response.pdf
