Microgrid Protection Using Magneto-Resistive Sensors and Superimposed Reactive Energy

Round 1

Reviewer 1 Report

The present work “Microgrid protection using magneto resistive sensors and super imposed reactive energy” proposes a MR sensor and superimposed reactive energy (SRE)-based protection scheme for short-circuit faults in microgrids. However, there are some Minor corrections which needs to be addressed.

1.     Introduction: There is lack of cohesiveness in this section. Authors need to improve the last paragraph of introduction section to clearly present the novelty of the work.

2.     Line 155: Figure 1 ? Position vectors are not visible in the cited figure. Please add.

3.     VALIDATION: How the authors validated their obtained results. With how much confidence interval, authors say their results are correct?

4.     Add a separate sheet of nomenclature to understand the various abbreviation, formulas etc. used in the manuscript.

5.     Line 433: Comparative analysis. The section needs improvement as very little explanation is given.

6.     Conclusion: this section is little weak. Rephrase and provide the crisp conclusions of the work.

Author Response

 

Response to Reviewer 1

 

 

 

Dear Reviewer:

We would like to thank you for your insightful suggestions and comments, which have helped a lot in improving the quality of our paper. We have revised our paper by incorporating all your suggestions and comments.

The modifications are highlighted in yellow colour in the revised manuscript.

 

 

Response:

The authors are extremely thankful to the reviewer for the constructive comments. We have carefully studied all the comments. The detail response of each comment is given below point by point.

1) Reply:

We are thankful to the respected reviewer for pointing this out. We have modified our contributions in the paper and listed down in the last paragraph of the introduction. The modifications are highlighted in yellow colour in the revised version of the manuscript.

 

 

2) Reply:

            Thank you so much for highlighting this mistake. We have added the figure 3 in the revised version of the manuscript demonstrating the position vectors with respect to figure 1 in detail.

Figure. 3: Magnetic Field at Sensor’s point due to current in phase a,b and c

3) Reply:

The authors are thankful to the respected reviewer for pointing this out. We have performed extensive testing on the Test Microgrid keeping in view all the possible configurations and faults and results shows accuracy of about 97-98%.

 

4) Reply:

Thank you so much for pointing this out. Here is the list of all of abbreviation used in the manuscript. Also, authors have added the list at the last of manuscript before the references.

MR Sensors	Magneto-resistive Sensors
B	Magnetic Field
DER	Distributed Energy Resources
DG’s	Distributed Generators
SRE	Super Imposed Reactive Energy
SIQ	Super Imposed Quantities
FF	Forward Fault
RF	Reverse Fault
MP	Main Protection
BP	Backup Protection
det.	Detection
dir.	Direction
ADC	Analog to Digital Convertor
R	Relay
Thres	Threshold
IIDG	Inverter Interfaced Distributed Generator
BTS	Breaker Trip Signal
HIF	High Impedance Fault
GCM	Grid connected Mode
ICM	Islanded Mode
LGCM	Looped Grid connected Mode
LIM	Looped Islanded Mode
PCC	Point of Common Coupling

 

5) Reply:

Thank you so much for pointing this out. We have compared the presented cases in detail in the manuscript. All the cases are explained in detail with the results in the pointed section. The modifications are highlighted in yellow colour in the revised version of the manuscript.

6) Reply:

We are thankful to the reviewer for the constructive comments. We have reorganized and improved the conclusion section and added in the revised manuscript in detail in section 6 “Conclusion”.

-------------------------- End of Reviewer 1’s Comments --------------------------

Author Response File: Author Response.docx

Reviewer 2 Report

 

 

1.      Statistical significance of the result is required.

2.     Some minor copy editing errors are present in the paper.

3.      The writing structure is bad. it is still hard to understand every detail in this paper.

4.     Wording issues, typos and grammar mistakes are too many.

5.     Background and methodology are mixed in many parts, which makes it hard to understand the technical contributions.

6.      Unfair evaluation and missing details.

 

7.      The contributions are not clearly introduced / not proven.

Author Response

 

Response to Reviewer 2

 

 

Dear Reviewer:

We would like to thank you for your insightful suggestions and comments, which have helped a lot in improving the quality of our paper. We have revised our paper by incorporating all your suggestions and comments.

The modifications are highlighted in yellow colour in the revised manuscript.

The authors are extremely thankful to the reviewer for the constructive comments. We have carefully studied all the comments. The detail response of each comment is given below point by point.

1) Reply:

We are thankful to the respected reviewer for pointing this out. After immense simulation on the Test Microgrid we have concluded that presented scheme works well with the efficiency of about 97-98%. The modifications are highlighted in yellow colour in the revised version of the manuscript.

 

2) Reply:

            Thank you so much for highlighting this mistake. We have updated the revised manuscript and try to resolve minor mistakes that you have highlighted.

3) Reply:

The authors are thankful to the respected reviewer for pointing this out. We have proof read the paper and resolved the issues to the best of our knowledge.

 

4) Reply:

Thank you so much for pointing this out. We have thoroughly revised the paper and try to fix all typos and grammatical mistakes.

5) Reply:

Thank you for highlighting this issue. We have done amendments regarding this and hopefully the newer version of the manuscript wil satisfy your needs and requirements.

6) Reply:

Thankyou so much for your comment. Unfortunately authors are unable to understand the comment of this reviewer. Sorry for this confusion.

7) Reply:

Thank you so much for addressing this issue. The main contributions of this paper are:

• The presented scheme can non-intrusively sense the faulty conditions using MR sensors without any modification or disturbance to the current system.
• The scheme works well with radial as well as looped micro-grids with different configurations against solid faults having the capability of single line tripping.
• The proposed protection mechanism works well with both grid-tied and islanded without any changes in relay setting during the transition of operational modes.

Above mentioned points are proved through testing and explained in detail in the section 4 “Simulation results and Discussion” along with the results.

Author Response File: Author Response.docx

Reviewer 3 Report

Please, revise this paper considering the following issues: 

1. Rearrange abstract part to show the contribution of your study with numerical findings. 

2. Move Figure 1 after its citation.

3. More description of the simulation results is needed. 

4. The paper must be follow the MDPI instructions. Many free spaces are noticed. 

5. Extend the work with different types of simulatenous faults

6. Extend conclusion section with the futrue extention 

Author Response

 

Response to Reviewer 3

 

 

 

Dear Reviewer:

We would like to thank you for your insightful suggestions and comments, which have helped a lot in improving the quality of our paper. We have revised our paper by incorporating all your suggestions and comments.

The modifications are highlighted in yellow colour in the revised manuscript.

 

 

Response:

The authors are extremely thankful to the reviewer for the constructive comments. We have carefully studied all the comments. The detail response of each comment is given below point by point.

1) Reply:

The concept of microgrids has emerged as an effective way to integrate distributed

energy resources (DERs) into the distribution networks. The presence of DERs in the

microgrids leads to challenges in the formulation of protection for microgrids.  Protection problems arise in a microgrid due to varying fault current levels in different operating scenarios. In order to overcome the practical challenges arising from varying fault current levels leading to short-circuit faults in microgrids, this paper proposes a MagnetoResistive (MR)sensors based protection scheme, with fault localization through SuperimposedReactiveEnergy (SRE). The process is initiated by employing highly sensitive non-intrusive magnetic sensors to detect magnetic field at each end of the distribution line within 10 Nano seconds. The magnetic field is, then, used to calculate the total harmonic distortion and thus detect the faults in the microgrids. After detection of faults, the proposed scheme uses SRE to identify the faulty zone in the microgrids. Finally, SI components of current are extracted for fault classification. Extensive simulations on International Electro-technical Commission (IEC) microgrid are performed in MATLAB/Simulink to validate the efficacy of the proposed scheme. The proposed scheme can efficiently detect the fault within 0.5 cycle i.e 8ms after the occurrence of fault. Moreover, it can isolate the faulty phase after 3.5 cycles of faulty event.Simulation results show that the proposed scheme can effectively detect, classify and isolate all types of solid faults in microgrid, while operating under various modes with varying fault locations and resistances, with the efficiency of approxiametly 97%-98%.

2) Reply:

            Thank you so much for highlighting this mistake. We have updated the figure after its citation in the revised manuscript.

3) Reply:

The authors are thankful to the respected reviewer for pointing this out. We have explained all the presented cases in detail along with the results describing and analyzing each result in the manuscript. Added details are highlighted in yellow colour in the revised manuscript.

 

4) Reply:

Thank you so much for pointing this out. The paper is arranged according to the defined rules of MDPI. All the unnecessary spaces and left page are rearranged in the revised manuscript.

 

5) Reply:

Thank you so much for pointing this out. Extensive simulations have been performed during testing on MATLAB/Simulink considering all types of faults that includes LG, LLG, LLLG, LL and LLL under all configurations of grid connected as well as islanded mode. But due to limited space few of them were discussed in the paper along with the results.

 

6) Reply:

We are thankful for the reviewer for highlighting this point. In future work, the proposed scheme will be implemented and tested

• On HIF’s with little design modifications.
• For backup protection in case the main protection fails to secure the system during faults or during the transition mode i.e., from grid connected to islanded mode and from islanded to grid connected mode.
• The improved variant will be simulated to test the efficiency on different larger systems with different configurations.

 

 

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

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Reviewer 3 Report

Additional comments are needed: 

1. Discussion on the simultaneous faults is needed. 

2. Evaluation of the proposed scheme must be extended. 

3. Future work based on the limitations.