Research on Transmission Network Expansion Planning Considering Splitting Control
Round 1
Reviewer 1 Report
My recommendation is to reconsider after some major revisions.
The use of English language is fine without any major revisions.
However, there are some major things to consider
1. Figures, 5, 6, 9, 10
(a) The units should be in brackets not /
(b) The meaning and significance of these graphs are not properly emphasized and described in the text.
2. Conclusions
The level of success of this work is not properly emphasized in the conclusions. The conclusions should include the aims/objectives supported by the related results. This is not shown at all.
Author Response
Thank you very much for your review. The specific reply is in the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This paper presents an interesting approach regarding the transmission network expansion planning. However, there are some issues that should be addressed prior to its publication:
The constraints (e.g. min/max of line sensitivity in (13) and the constraints in (17)-(21)) should be further explained and justified (what the limits could be and for which reason). The contribution of the paper and the novelty comparing with the state of the art should be clearer. The figures regarding the grid planning (figs. 3,4,7 and 8) are not clear enough and not adequately explained within the text. Please, clarify and elaborate further. The figures concerning the generator power angle curve are under-explained and misleading. For example, how is it possible to have 2000 degrees phase angle? Please, elaborate and justify further. In addition, figures 9 & 10 are hardly explained. The nomenclature could be preferably moved to the beginning of the manuscript, unless it is differently dictated by the journal template.Author Response
Thank you very much for the expert teacher's comments. The specific reply is attached.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
I would like to thank you for addressing my comments.
Regarding Figures, 5, 6, 9, 10 the angle is shown as Radians which is ok.
Do not forget to label each curve; figure 9 is not labeled.
Figure 5, at t=3s the angle of G14 increases to approximately 50 radians. Please, correct me if I am wrong, but this implies that G14 is spinning faster and it is also delivering more power in the system. Can G14 handle this increased speed? Do you take into consideration the G14 constraints?
Question: Since the angles keep increasing then why did you stop at t=4s?what happens at t=10s? Or this is not an option? Please elaborate.
Also, at t=1s when the generators start increasing their angles then is the demand met? if yes then why do the generators keep increasing their angles?
An example of what I mean with significance of the angles showed on figures 5, 6, 9, 10. When a fault occurs according the results of figure 5, in order to the demand to be met then generators should increased then angles. At t=2s G14, G2, G5 and G11 should increase their angle at 15rad whereas G10, G16 and G18 should increase at 10 rad. At t=3s angles increases even more etc.
I apologize in advance because I might be missing something. If that is the case then please elaborate. However, as is then the results are confusing to me.
Thank you.
Author Response
Thanks to the experts for their comments, see the attachment for details.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors have addressed this reviewer's comments adequately. Therefore, this paper is recommended for publication.
Author Response
Thanks for the opinion of the reviewer, which has helped me a lot.
