Small-Signal Modeling of Grid-Forming Wind Turbines in Active Power and DC Voltage Control Timescale

Comments 1: A line can be added to abstract, regarding the simulation tools used for this proposed model.

Response 1: Thanks for your the kind consideration. We agree with this comment. Therefore, we have added the description of simulation tools in Abstract.

Comments 2: Is this sentence correct? "Based on the system control configuration and the assumptions in Section II, Figure.3 illustrates the dynamics diagram of a GFM-WT in APC and DVC joint timescale."

Response 2: This is not correct sentence. I have already changed it to the correct description in section 2.1.

Comments 3:  The references made to fig 2, 3 are not clear

Response 3: Thank you for your significant reminding. According to your suggestion, I have checked all the references related to fig 2, 3 and corrected the related references.

Comments 4:  Section 4. The sentence needs correction. “The system is instability at J=4.”

Response 4: Thanks for your careful checks. l have already modified this sentence to "The system is unstable at J=4" in section 4.1.

Comments 5:  Can the values be added for J=2, 10-16 to table 2 and for KI1 = 20, 200 to table 3?

Response5 : Thanks for your suggestion. I have already added more experimental results in section 4.1 and section 4.2.

Comments 6:   What computational methods are used to calculate eigenvalues?

Response6 : Thanks for your question. The pole-zero map of the liner analysis tool in Simulink is used to calculate eigenvalues. We perform linearization analysis on mathematical models built on Simulink using this tool. The distribution of zero and pole points can be obtained.

Comments 7:   What are the limitations observed using small-signal stability analysis for the proposed model?

Response7 : Thanks for your question. For the proposed model, we can get find the control loops that affect stability by the eigenvalue analysis. Nevertheless, the small-signal model established in this paper is aimed at virtual synchronous control, and further research is needed for different grid-forming control strategies currently.