Fractional-Order Phase Lead Compensation Multirate Repetitive Control for Grid-Tied Inverters

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please see the attached report.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

Please review the PDF document. Thanks.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Abstract

- the abstract reflects well the content of the paper.

Introduction

- mostly, refers to the importance of the repetitive control (RC) for the grid-tied inverters;

- the RC strategy combined with other feedback controllers are, or could be, solutions for the grid-tied inverter control;

- this scenarios, developed in the literature, are well documented and presented by the authors;

- the contributions of the paper are also mentioned. 

Modeling the Single-Phase PWM Inverter

- the model of the single-phase LCL-type grid-tied PWM inverter is presented with clear explanations;

- however, the title of the section is "Modeling..." and the authors present, direct, the transfer function, without "modeling" (at least the beginning of the modeling, with the balance equations of the voltages/current);

- also, here it is important to mention the method used to discretization (zoh, tustin etc.).

MRC

- firstly, I recommend to use for the title the full name of MRC (Multirate...); same for the subsections 3.2 and 3.3;

- the structural diagram of CRC and the transfer function are clear;

- in Figure 3. Structural diagram of the PIMR-RC system, it is not very clear where the Integrator (I) effect is, in order to have a PI controller;

- the structural diagram of the PIMR-MRC system (Fig. 4) and the equivalent of this (Fig. 5) are well presented;

Fractional-Order Phase Lead Compensation MRC

- takes into consideration ki, d as the integer and fractional parts of k;

- then, result the Structural diagram of the FPL-PIMR-MRC based on the IIR filter and the frequency characteristics (Fig. 8);

- the two stability conditions are correct.

Parameters Design of FPL-PIMR-MRC

- here, in the first sentence, it should be good if the five parameters would be enumerated;

- according to the Fig. 9a,b the choosing of the kp=16 is justified;

- also, the Nyquist curves (Fig. 11) and Bode curves (Fig. 12) are very well exploited.

Simulation

- the results are obtained using MATLAB/Simulink software;

- the steady-state responses are compelling;

- same for the transient responses.

Conclusions

- the research content is well summarized in this section;

- however, being a paper of "Fractional-Order...", some additional conclusions about the effect of the fractional part would be in a favor of the paper.

The References are suggestive for the topic. Random check for: 1. Chen, D.; 5. Zhou, K.; 9. Zhang, K.; 12. Wu, W.; 17. Zeng, C.; 23. Kurniawan, E.; 32. Guo, Q.; 37. Zhao, Q.

Author Response

Please review the PDF document. Thanks.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I am satisfied with the revision.

Reviewer 2 Report

Comments and Suggestions for Authors

My observations were taken into consideration.