Review Reports - An Active Distribution Grid Exceedance Testing and Risk-Planning Simulation Based on Carbon Capture and Multisource Data from the Power Internet of Things

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors of the paper entitled "An Active Distribution Grid Exceedance Testing and Risk Planning Simulation Based on Carbon Capture and Multi-Source Data from the Power Internet of Things" brings many new perspective in the field, however I have following comments:
1) Did you put different weights on different Risk-planning model for distribution networks based on the Internet of Things for electricity. ..? How these weights can be associated.?
2) Is any real-time simulation possible for the presented case..?

Author Response

Did you put different weights on different Risk-planning model for distribution networks based on the Internet of Things for electricity. ..? How these weights can be associated.?

Response: The exceeding probability calculation method in the manuscript is based on the fact that the exceeding probability of distribution network nodes and lines at each moment can be obtained by expanding the voltage and power of each node and line in different scenarios in a hierarchical manner. In the example, the largest exceeding probability of each node and line is selected as the exceeding probability of the distribution network.

Is any real-time simulation possible for the presented case..?

Response: Real-time simulation requires the provision of real-time operational data, which is currently difficult to realize due to the low accuracy of active power prediction of wind turbines and photovoltaic generators. If the system does not contain distributed generation equipment, the solution speed of the exceedance testing model can meet the demand of real-time simulation.

Reviewer 2 Report

Comments and Suggestions for Authors

The paper proposes an active distribution network risk planning model based on 13 data from multiple carbon capture sources and the Power Internet of Things.

The article is relevant and is at the state of the art of knowledge and application of the models are adequate, however there are some recommendations that I suggest.

Increasing the size of Figure 6 and its quality could help to see the value boundaries more clearly.

Improve quality and size of figure 7 labels.

The results of the work are presented adequately, however they do not reveal a comparison and the formulation of the problem from other models as well as the quantitative comparison of this methodology with the existing one are not presented. Therefore, a section is necessary where this comparison is presented as well as the advantage and disadvantage with respect to what exists in the literature. Conclude regarding this analysis.

Author Response

The paper proposes an active distribution network risk planning model based on 13 data from multiple carbon capture sources and the Power Internet of Things.

The article is relevant and is at the state of the art of knowledge and application of the models are adequate, however there are some recommendations that I suggest.

Increasing the size of Figure 6 and its quality could help to see the value boundaries more clearly.

Improve quality and size of figure 7 labels.

Response: Thanks to your suggestions, we have completed the changes to figures.

Reviewer 3 Report

Comments and Suggestions for Authors

1) This work talks about the active distribution grid exceedance testing and risk planning-simulation based on carbon capture and multi-source data from the power internet of things. 2) The work proposes that in order to achieve peak carbon and carbon neutrality targets, a high number of distributed power sources have been connected to distribution networks, which greatly increase the risk posed to a distribution network’s operation. To solve the above problem while promoting sustainable development, this work proposes an active distribution network risk-planning model based on multi-source data from carbon capture and the Power Internet of Things. The model calculates the semi-invariants of each order of the node state vectors and branch circuit current vectors, and then utilizes Gram–Charlier-level expansion to obtain the exceeding probability density function and the probability distribution functions of the node voltages and line powers in the distribution network. Combined with multi-source data, an active distribution network with an integrated energy system designed for carbon capture was modeled. According to the risk scenario of the distribution network, the nonconvex constraints in the model were simplified by second-order cone relaxation, and the optimal planning scheme of the distribution network was solved by combining the Gurobi solver with the risk index as the first-level objective and the economic benefit as the second-level objective. The simulation results of a coupled network consisting of a 39-node distribution network and an 11-node transportation network verified the effectiveness of the proposed model. 3) The work has potential. However, it requires a major revision. 4) The abstract is written well. However, it is missing a clear problem statement. The problem statement should be defined in the first 1-2 lines of the manuscript. This would allow to improve the readability of your work. 5) The keywords are not sufficient. There are many possible keywords which could address the scope of this work. 6) The introduction section is the weakest of this work. This works claims alot. However, it is not properly defined in the introduction section. The detail of elements missing in the introduction section can be seen in the following comments. 7) What is the contribution of the paper ? It must be clearly mentioned in the introduction. So far, this elements is not obvious in the introduction. 8) What is the motivation of the paper ? It must be clearly mentioned in the introduction. So far, this elements is not obvious in the introduction. 9) What is the scope of the paper ? It must be clearly mentioned in the introduction. So far, this elements is not obvious in the introduction. 10) There are many decent works in this area. What are the preceding affined reviews in the same direction. A comprehensive table expressing the limiting of previous works in this area, their limitation, and reason of your proposing this work shall be expressed in the end of introduction section. This is a very important aspect to ensure that it is not yet just another paper to publish and it is bringing novelty to the readers. 11) The section before simulation results require a direction. The reader can easily be lost while losing the flow of work. Either some of the sections should be merged. Or there should be a framework diagram which could possibly address and connect all the sections together to improve the readability of work. 12) For a Journal paper talking about the exceedance testing and risk planning, how the proposed scheme differentiated between the system faults and deliberately injected faults (in the form of cyber attacks) and how to confirm that the fault is not deliberated ? 13) There should be a pseudo code or flow chart to convolute the proposed scheme before the results and simulation section. Pseudo codes are usually considered for mathematical formulation driven work. In this work, a possible pseudo code could be designed for practitioners to understand things smoothly. The variables of input and output are required to be defined in the pseudo code. And then that defined language is required to be used in the rest of the lines. Please follow the above steps accordingly. 14) In the case study section, what main-stream techniques are utilized for comparison? The superiority of your proposed scheme shall be mentioned in the conclusion based on the outcome of comparison with other main-stream techniques. 15) For a Journal paper talking the risk planning and exceedance testing, a discussion on secure communication, cyber-physical infrastructure, and the elements of digitalization must be flavored more in the introduction. This is much required since power is transferred and communicated using the internet-of-things. Some suggested references on the same are as follows: 1) Communication systems in distributed generation: A bibliographical review and frameworks, IEEE Access 8, 207226-207239, 2021, 2) WAMS operations in power grids: A track fusion-based mixture density estimation driven grid resilient approach towards cyber attacks. 3) WAMS operations in modern power grids: A median regression function-based state estimation approach towards cyber attacks. 16) The figure quality is required to be improved. The text inside figures should be visible. 17) References literally require an overall. A total of 19 supporting references for this kind of work is not adequate. Moreover, the format is not consistent. In some references, there is no page number mentioned. In others, the page number is at the end and year in the middle and vice versa. Also, in some, the first letter of the title of the paper is only capital. In others, all first letters of the titles of the paper are capital. Please visit the styling again and maintain consistency.

Comments on the Quality of English Language

moderate editing of english is required.

Author Response

1) This work talks about the active distribution grid exceedance testing and risk planning-simulation based on carbon capture and multi-source data from the power internet of things.

2) The work proposes that in order to achieve peak carbon and carbon neutrality targets, a high number of distributed power sources have been connected to distribution networks, which greatly increase the risk posed to a distribution network’s operation. To solve the above problem while promoting sustainable development, this work proposes an active distribution network risk-planning model based on multi-source data from carbon capture and the Power Internet of Things. The model calculates the semi-invariants of each order of the node state vectors and branch circuit current vectors, and then utilizes Gram–Charlier-level expansion to obtain the exceeding probability density function and the probability distribution functions of the node voltages and line powers in the distribution network. Combined with multi-source data, an active distribution network with an integrated energy system designed for carbon capture was modeled. According to the risk scenario of the distribution network, the nonconvex constraints in the model were simplified by second-order cone relaxation, and the optimal planning scheme of the distribution network was solved by combining the Gurobi solver with the risk index as the first-level objective and the economic benefit as the second-level objective. The simulation results of a coupled network consisting of a 39-node distribution network and an 11-node transportation network verified the effectiveness of the proposed model.

3) The work has potential. However, it requires a major revision.

4) The abstract is written well. However, it is missing a clear problem statement. The problem statement should be defined in the first 1-2 lines of the manuscript. This would allow to improve the readability of your work.

Response: In order to achieve peak carbon and carbon neutrality targets, a high number of distributed power sources have been connected to distribution networks. How to realize the planning of distribution network containing integrated energy under the condition of carbon capture and complete the exceedance testing of distribution network under the condition of accessing a large number of distributed generators has become an urgent problem.

5) The keywords are not sufficient. There are many possible keywords which could address the scope of this work.

Response: active distribution networks; exceedance testing and risk planning; Power Internet of Things; semi-invariant method; integrated energy; second-order cone; probability flow.

6) The introduction section is the weakest of this work. This works claims alot. However, it is not properly defined in the introduction section. The detail of elements missing in the introduction section can be seen in the following comments.

7) What is the contribution of the paper? It must be clearly mentioned in the introduction. So far, this elements is not obvious in the introduction.

8) What is the motivation of the paper? It must be clearly mentioned in the introduction. So far, this elements is not obvious in the introduction.

9) What is the scope of the paper? It must be clearly mentioned in the introduction. So far, this elements is not obvious in the introduction.

Response: In order to realize the safe access of new energy generators, electric vehicles, and integrated energy systems to the distribution network, this paper establishes a risk planning model, which can realize the address selection and capacity determination of new energy generators and electric vehicles, and at the same time, it can regulate the energy storage equipment- to realize the efficient utilization of diversified energy. Finally, the exceedance testing model can assess the risk of the completed distribution network framework, and calculate the exceedance probability of voltage at each node of the distribution network and the exceedance probability of power at each branch under different scenarios. In this paper, simulations are conducted on the IEEE examples with total loads of 5.57 MW and 6.47 MW, respectively, to verify the effectiveness of the model.

10) There are many decent works in this area. What are the preceding affined reviews in the same direction. A comprehensive table expressing the limiting of previous works in this area, their limitation, and reason of your proposing this work shall be expressed in the end of introduction section. This is a very important aspect to ensure that it is not yet just another paper to publish and it is bringing novelty to the readers.

Response: Thanks to your suggestions, we have completed the changes to tables (Table 1 and Table 5).

From the results of the four planning schemes laid out above, it can be seen that considering only wind turbine generators or photovoltaic generators would result in the probability of the voltage exceeding the limit by more than 10%, indicating a serious risk level. If both wind turbines and photovoltaic generators are considered, the voltage exceedance probability decreases to 8.42%, but this risk is still too high. After incorporating carbon capture technology, the voltage exceedance probability decreases to 0.05%; thus, the risk level is safe. Furthermore, considering wind turbine and photovoltaic generators can enhance the economic benefits of the system and the annual investment costs decrease from USD 4.82 million and 4.41 million to 4.18 million and 4.25 million. If genetic algorithm is used for optimization, it can be found that the optimization results of each scheme cannot reach the effect of second-order cone optimization, and at the same time, the optimization time is more, so the second-order cone algorithm is chosen as the main optimization method of the model. Improving the distribution network will require access to both wind turbines and photovoltaic generators; otherwise, there will be a high risk of the lower limit of the distribution network’s node voltage being exceeded. At the same time, there remains a certain risk that the upper limit will be crossed, and incorporating carbon capture technology in the improvement of the network can improve the overall energy utilization efficiency of the system, which not only resolves part of the carbon dioxide emitted by the gas turbine, but also, through energy conversion and storage, reduces the impact of integrated energy nodes on the entire network. Although carbon capture devices increase investment costs from the security and environmental points of view, Scheme 4 should be selected as the planning program.

11) The section before simulation results require a direction. The reader can easily be lost while losing the flow of work. Either some of the sections should be merged. Or there should be a framework diagram which could possibly address and connect all the sections together to improve the readability of work.

Response: Thanks to your suggestions. We chose to draw a flowchart to explain our modeling framework (Figure 3.)

12) For a Journal paper talking about the exceedance testing and risk planning, how the proposed scheme differentiated between the system faults and deliberately injected faults (in the form of cyber attacks) and how to confirm that the fault is not deliberated ?

Response: Thank you for your suggestion, our manuscript is not very well researched in this area, and we hope that we can further improve the results in this area in our next work.

13) There should be a pseudo code or flow chart to convolute the proposed scheme before the results and simulation section. Pseudo codes are usually considered for mathematical formulation driven work. In this work, a possible pseudo code could be designed for practitioners to understand things smoothly. The variables of input and output are required to be defined in the pseudo code. And then that defined language is required to be used in the rest of the lines. Please follow the above steps accordingly.

Response: Thanks to your suggestions. We chose to draw a flowchart to explain our modeling framework (Figure 3.)

14) In the case study section, what main-stream techniques are utilized for comparison? The superiority of your proposed scheme shall be mentioned in the conclusion based on the outcome of comparison with other main-stream techniques.

Response: Thanks to your suggestions. We have added a comparison of the genetic algorithm with the second-order cone algorithm to highlight the superiority of the second-order cone algorithm(Table 5).

15) For a Journal paper talking the risk planning and exceedance testing, a discussion on secure communication, cyber-physical infrastructure, and the elements of digitalization must be flavored more in the introduction. This is much required since power is transferred and communicated using the internet-of-things. Some suggested references on the same are as follows: 1) Communication systems in distributed generation: A bibliographical review and frameworks, IEEE Access 8, 207226-207239, 2021, 2) WAMS operations in power grids: A track fusion-based mixture density estimation driven grid resilient approach towards cyber attacks. 3) WAMS operations in modern power grids: A median regression function-based state estimation approach towards cyber attacks.

Response: Thank you for the references, we have added them to the article. “Distribution networks directly affect power users and are responsible for the important task of power distribution, which plays a key role in the economics, security, and stability of power grids and facilitates the integration of distributed equipment into the grid. The development of digital technologies likewise poses significant challenges to the security and reliability of smart grid networks [1-4]. With integrated energy systems, traditional power data collection platforms have fewer monitorable points, require a single type of monitoring data, and lack multivariate data-processing functions. Existing distribution network risk-planning techniques are becoming increasingly difficult to adapt and apply in relation to the special requirements of smart and transparent distribution networks.”

16) The figure quality is required to be improved. The text inside figures should be visible.

Response: Thanks to your suggestions, we have completed the changes to figures.

17) References literally require an overall. A total of 19 supporting references for this kind of work is not adequate. Moreover, the format is not consistent. In some references, there is no page number mentioned. In others, the page number is at the end and year in the middle and vice versa. Also, in some, the first letter of the title of the paper is only capital. In others, all first letters of the titles of the paper are capital. Please visit the styling again and maintain consistency.

Response: Thanks to your suggestions, we have increased the number of references and completed the revision of the reference format.

Reviewer 4 Report

Comments and Suggestions for Authors

The paper presents an innovative approach to address the challenges posed by the increasing integration of distributed power sources into distribution networks. The proposed active distribution network risk-planning model, leveraging multi-source data from carbon capture and the Power Internet of Things, offers a comprehensive solution for promoting sustainable development while managing operational risks effectively. However, some clarification and additional information are needed to fully assess the novelty and effectiveness of the proposed model.

1. The novelty of the risk assessment methodology using Gram-Charlier expansion needs further clarification.

While the conclusion mentions economic benefits, a clearer explanation of how these are incorporated into the two-layer planning model is needed.
The computational efficiency of the model, particularly with the commercial solver (Gurobi), should be addressed.
A more detailed comparison with existing risk assessment methods for distribution networks would be valuable.

Comments on the Quality of English Language

The English usage of this manuscript needs improvement. There are typos and grammar mistakes.

Author Response

The novelty of the risk assessment methodology using Gram-Charlier expansion needs further clarification.

While the conclusion mentions economic benefits, a clearer explanation of how these are incorporated into the two-layer planning model is needed.

The computational efficiency of the model, particularly with the commercial solver (Gurobi), should be addressed.

A more detailed comparison with existing risk assessment methods for distribution networks would be valuable.

Response: Complex convolutional operations can be simplified using the numerical feature of semi-invariance. The semi-invariants of the load margin are obtained by solving the semi-invariants of the input variables and the sensitivity matrix. A semi-invariant has two important properties: additivity and homogeneity. As a result of these two properties, linear combinations of random variables can be transformed into linear operations of their semi-invariants; this is essential when simplifying stochastic analysis calculations. Compared to other probabilistic power flow methods the analytical method represented by the Gram-Charlier algorithm has faster solution speed and computational accuracy.

In order to highlight the advantages of the second-order cone algorithm with the gurobi solver, we have added a table （Table.5）comparing it with the genetic algorithm (NSGA-II) to the calculus.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The paper has been revised well. The comments have been addressed adequately. The missing corners have been structured. Usually in such papers, the readers gets lost due to the heavy mathematics, write-up, and a feel that it is yet another technical paper. However, in its current form, the reader should find it very easy to read the work and to understand, implement the idea, and the reason of structuring it.