Hardware-Accelerated SMV Subscriber: Energy Quality Pre-Processed Metrics and Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I have reviewed this manuscript entitled "Hardware-Accelerated SMV Subscriber: Energy Quality Pre-Processed Metrics and Analysis". This work aims to present an advanced, hardware-accelerated subscriber for Sampled Measured Values. The author also did an effort in illustrating how sophisticated monitoring capabilities can be effectively integrated into communication-centric devices, significantly contributing to the development of more intelligent, robust, and resilient electrical grids. Overall, the manuscript is well structured and meaningful. I raised the following comments to help the authors improve the quality of the manuscript.

1) Abstract can be rewritten more scientifically. Abstract has to address briefly and describe aim, object, procedure, important findings/understanding of novelty accordingly.

2) The current Introduction is weak. Please boost your Introduction. please outline the authors' detailed views on the key challenges, existing research gaps.

3) It is not clear on which basis, Figure 21 was formed. It needs to be explained.

4) Section 4 Error Analysis: Is it necessary to mark the error bar in the figures?

 

5) The authors should improve the Figure. All the legends must be corrected and the resolution should be ensured.

6) The conclusion should summarize the major numerical results in a concise manner, thereby highlighting the research contents. Please put enough emphasis on the points of novelty of the proposed study in your Conclusions.

Author Response

We would like to thank the reviewers for their thoughtful evaluations and constructive suggestions, which have substantially strengthened the clarity, rigour, and presentation of our manuscript.

 

I have reviewed this manuscript entitled "Hardware-Accelerated SMV Subscriber: Energy Quality Pre-Processed Metrics and Analysis". This work aims to present an advanced, hardware-accelerated subscriber for Sampled Measured Values. The author also did an effort in illustrating how sophisticated monitoring capabilities can be effectively integrated into communication-centric devices, significantly contributing to the development of more intelligent, robust, and resilient electrical grids. Overall, the manuscript is well structured and meaningful. I raised the following comments to help the authors improve the quality of the manuscript.

[Comment 1] Abstract can be rewritten more scientifically. Abstract has to address briefly and describe aim, object, procedure, important findings/understanding of novelty accordingly.
Response 1. We have rewritten the Abstract to highlight the study’s aim and scope, the problem setting, the proposed hardware-accelerated SMV subscriber with pre-processed power-quality metrics and the methodological approach (including the evaluation procedure). The Abstract now explicitly articulates the contribution and novelty and situates them within the broader literature.

[Comment 2] The current Introduction is weak. Please boost your Introduction. please outline the authors' detailed views on the key challenges, existing research gaps.
Response 2. The Introduction has been substantially expanded and restructured to: (i) synthesise recent work on SMV processing and power-quality monitoring; (ii) identify the key challenges (throughput/latency constraints, determinism, resource contention, measurement fidelity, and interoperability); and (iii) articulate the research gaps our work addresses. We also clarify the problem formulation and position our contributions relative to the state of the art.

[Comment 3] It is not clear on which basis, Figure 21 was formed. It needs to be explained.
Response 3. The former Figure 21 is now Figure 14. It has been redrawn for clarity, and we added a dedicated explanatory paragraph in the main text and an expanded caption.

[Comment 4] Section 4 Error Analysis: Is it necessary to mark the error bar in the figures?
Response 4. We agree that explicit error bars are not necessary for our purposes. We removed the error-bar panels and now report dispersion succinctly in the text. Figure 12 (formerly 18) has been updated accordingly, and the error-analysis narrative has been revised for consistency across the section.

[Comment 5] The authors should improve the Figure. All the legends must be corrected and the resolution should be ensured.
Response 5. All figures have been regenerated from the original sources to ensure high resolution. Legends and axis labels have been corrected and standardised, units are stated explicitly, and numbering and in-text references have been synchronised.

[Comment 6] The conclusion should summarize the major numerical results in a concise manner, thereby highlighting the research contents. Please put enough emphasis on the points of novelty of the proposed study in your Conclusions.
Response 6. The Conclusions now concisely summarise the major numerical results and emphasise the novelty and practical implications of the proposed approach.

 

Reviewer 2 Report

Comments and Suggestions for Authors

The review report of the paper can be found in the attached file.

Comments for author File: Comments.pdf

Author Response

We would like to thank the reviewers for their thoughtful evaluations and constructive suggestions, which have substantially strengthened the clarity, rigour, and presentation of our manuscript.

 

The efficient operation of electrical and electronic consumers requires that their supply voltage meets the quality criteria imposed by the regulations in force. Also, the transmission of electricity is most efficient when the waveforms of voltages and currents are sinusoidal and the three-phase systems of voltages and currents are symmetrical. In order for electricity suppliers to ensure the quality of electricity necessary for the proper operation of consumers, various quality coefficients for electricity have been introduced. As a result, the control of electricity quality is verified by determining the quality coefficients of electricity at the low voltage outputs of MV/LV transformers. Considering the number of MV/LV transformers in the world, I consider the problem studied in the paper “Hardware-Accelerated SMV Subscriber: Energy Quality Pre-Processed Metrics and Analysis” to be very useful and important. By publishing the paper, an efficient solution, superior to those presented in the literature, is made available to specialists in the electrical energy field for measuring the quality coefficients of electrical energy at the level of the electrical consumer.

 

[Comment 1] Chapter 3 contains many details familiar to specialists and could be eliminated to reduce the page count.
Response 1. Section 4.1 (formerly 3.1) has been substantially condensed. We removed background material that is standard in the digitalization of electric power systems, retaining only what is necessary to understand our design choices.

[Comment 2] The number of references can be increased; many recent works on power quality exist.
Response 2. The reference list has been expanded to include additional recent contributions on power-quality assessment, SMV processing, and embedded/FPGA-based implementations. The related-work section now better situates our approach within the current literature.

[Comment 3] Power-quality control is imposed by consumers (via supply contracts), not by the network; smart grids enable on-line determination of quality coefficients. This should be specified.
Response 3. We agree. The Introduction and the several other sections now explicitly state that power-quality requirements are typically specified contractually and driven by end-users, with suppliers and network operators enforcing them through codes and service-level obligations. [Comment 4] Short computation time is essential for monitoring and especially for digital protection; this should be better highlighted.
Response 4. Thank you for this observation. This point motivates our work, we did our best to strengthen this important aspect in the paper.

[Comment 5] If the system uses new concepts, the authors should consider patenting prior to publication.
Response 5. We appreciate the advice. The present paper discloses the architecture and evaluation methodology while avoiding enabling details of any proprietary implementations. We are evaluating the patentability of specific components and will pursue protection as appropriate in advance of any further enabling disclosures.

[Comment 6] Active and reactive power are not quality factors; the relevant indicator is the power factor. The power factor of the consumer should be determined.
Response 6. Completely agreed about the active and reactive power not being factors of electric energy quality. We modified Table 2 to clearly specify that we are calculating the active power just so the software layer can calculate the power factor, using just 3 values provided by hardware, without any other requirement. The calculated active power is represented on 64 bits, and the resulting apparent power is also represented on 64 bits. The division is very resource-demanding to achieve in hardware, but the software layer can easily overcome this challenge.

[Comment 7] In Table 2, “amplitude of the effective value” is incorrect (the effective/RMS value is not an amplitude). “Total power” should be “apparent power”.
Response 7. Thank you for pointing this out. We have corrected the terminology throughout: “RMS value” replaces “amplitude of the effective value”, and “apparent power” replaces “total power” in Table 2, figure captions, and the main text. Symbols and units were harmonised accordingly.

[Comment 8] With an instrument of precision class 0.1, errors below 0.1 cannot be verified experimentally; the paper should specify the system errors more precisely.
Response 8. We completely agree with all of the aspects mentioned, but the errors presented in this paper are not representative of a system’s total errors. We are highlighting the additional absolute errors of the hardware implementation (fixed point format), concerning the values obtained in a high precision simulator, such as Octave (floating point format), using samples recorded from IEDs without access to their technical specification. The total system error calculation and the precision class determination require specific information regarding the sampling systems that send the encapsulated SMV data. The focus of the paper was the additional error drawback for calculating the energy quality parameters in parallel with decoding the raw data, using programmable hardware to achieve the minimum latency possible.

[Comment 9] Chapter numbering is inconsistent (Chapter 3 appears twice). Figures 15 and 16 lack clarity.
Response 9. The numbering has been corrected across the manuscript. Figures 15 and 16 (and related signal plots) were regenerated from the original data in high-resolution vector format with corrected legends, clearer line weights, and consistent typography to improve readability.

[Comment 10] A more appropriate title would be “High-performance numerical system for determining the quality of electrical energy.”
Response 10. We appreciate the suggestion. Because the work presents a complete hardware-accelerated SMV subscriber (within which the numerical engine is one subsystem), we retained the current title to reflect the full scope. We have, however, clarified in the Introduction that the numerical system is embedded in a broader SMV subscriber architecture.

Reviewer 3 Report

Comments and Suggestions for Authors

The article presents a technically robust and novel implementation of a hardware-accelerated SMV subscriber (HS3) that integrates real-time energy quality monitoring directly into an FPGA-based MPSoC architecture. It demonstrates originality by embedding energy-quality calculations (RMS, frequency, active power) into the data pipeline, achieving low-latency, deterministic processing in accordance with IEC 61850 standards. The authors provide a comprehensive and well-structured explanation of the architecture, supported by implementation details, conceptual diagrams, and performance comparisons with existing solutions, showcasing the practical advantages and potential scalability of the proposed system.

However, the paper is overly lengthy and suffers from verbosity and redundancy, which detracts from clarity and readability. While technically detailed, it lacks a concise and focused evaluation section that explicitly quantifies system performance (in terms of latency, resource utilization, or comparison to benchmarks). The discussion of trade-offs between hardware complexity and performance is limited, and there is minimal exploration of real-world deployment implications or potential limitations in terms of scalability, interoperability, and configurability under variable substation scenarios.

Proposed Modifications

1. Condense the manuscript by eliminating repetitive explanations and streamlining lengthy technical descriptions to improve readability and focus.
2. Add a dedicated performance evaluation section that presents summarized quantitative results for latency, throughput, and resource utilization to validate the effectiveness of the design.
3. Include a clear comparison table with competing state-of-the-art SMV subscriber systems, highlighting both functional and non-functional advantages of HS3 in a structured, concise format.
4. Clarify the practical deployment considerations by discussing interoperability with different IEC 61850 profiles and potential hardware limitations in real substation environments.
5. Expand on the scalability analysis by discussing how the system performs under increased ASDU counts or stream density beyond 512, including memory and timing constraints.
6. Simplify algorithm descriptions by moving detailed mathematical derivations to an appendix and focusing the main text on conceptual clarity and implementation impact.
7. Revise the abstract and conclusion to emphasize key findings, practical implications, and contributions, avoiding overly general or vague statements.
8. Proofread for technical consistency and grammar to eliminate typographical errors, ambiguous terms, and overly complex sentence structures.
9. Consider adding a use case or simulation scenario demonstrating the real-time advantages of HS3 in a representative substation automation setting.

Author Response

We would like to thank the reviewers for their thoughtful evaluations and constructive suggestions, which have substantially strengthened the clarity, rigour, and presentation of our manuscript.

 

The article presents a technically robust and novel implementation of a hardware-accelerated SMV subscriber (HS3) that integrates real-time energy quality monitoring directly into an FPGA-based MPSoC architecture. It demonstrates originality by embedding energy-quality calculations (RMS, frequency, active power) into the data pipeline, achieving low-latency, deterministic processing in accordance with IEC 61850 standards. The authors provide a comprehensive and well-structured explanation of the architecture, supported by implementation details, conceptual diagrams, and performance comparisons with existing solutions, showcasing the practical advantages and potential scalability of the proposed system.

However, the paper is overly lengthy and suffers from verbosity and redundancy, which detracts from clarity and readability. While technically detailed, it lacks a concise and focused evaluation section that explicitly quantifies system performance (in terms of latency, resource utilization, or comparison to benchmarks). The discussion of trade-offs between hardware complexity and performance is limited, and there is minimal exploration of real-world deployment implications or potential limitations in terms of scalability, interoperability, and configurability under variable substation scenarios.

[Comment 1] Condense the manuscript by eliminating repetition and streamlining lengthy technical descriptions.
Response 1. Section 4.1 (formerly 3.1) has been substantially condensed. We removed repetitive explanations and non-essential background, consolidated overlapping passages, and improved cross-referencing.

[Comment 2] Add a dedicated performance-evaluation section summarising latency, throughput, and resource utilisation.
Response 2. We added a dedicated section on performance evaluation (now Section 4.5). It reports methodology and summarised quantitative results for latency, throughput, and resource utilisation across configurations with different maxima of subscribed svIDs. To keep the section concise, we emphasise worst-case operating points and clearly state the test conditions and measurement procedure.

[Comment 3] Include a clear comparison table with state-of-the-art SMV subscribers, covering functional and non-functional aspects.
Response 3. We now include a concise comparison table that benchmarks HS3 against representative market offerings using publicly available documentation (functional coverage, profile support, channel density, configurability) and non-functional aspects (indicative latency classes, resource footprint where reported). The Introduction and related-work text were revised to explain the scope and limitations of such comparisons for a subsystem prototype.

[Comment 4] Clarify practical deployment, including interoperability with IEC 61850 profiles and hardware limits in substations.
Response 4. The interoperability with different SMV profiles represents one of the future optimization steps. Currently, we are aiming at validating several firmware versions and integrate them with a software driver package. The clear definition of the hardware-dependent parameters and the user-configurable parameters is still far from final.

[Comment 5] Expand the scalability analysis for ASDU counts/stream density beyond 512, including memory and timing constraints.
Response 5. Thank you for pointing out the scalability for stream density greater than 512. We have added a paragraph to clarify the current system capabilities and future development considerations.

[Comment 6] Simplify algorithm descriptions by moving detailed derivations to an appendix; focus the main text on concepts and implementation impact.
Response 6. We appreciate the suggestion to streamline the algorithmic sections by relocating detailed mathematical derivations to an appendix. In line with the other reviewer’s request to strengthen the paper’s scientific context—and following a careful reduction of redundant material in Section III—we have substantially tightened the presentation while preserving the essential derivations that underpin the hardware design. Given these revisions, we consider the current organisation strikes an appropriate balance between scientific soundness and readability.

[Comment 7] Revise the abstract and conclusion to emphasise key findings, practical implications, and contributions.
Response 7. The Abstract, Introduction, and Conclusions were revised to state the problem and scope clearly, highlight the principal quantitative findings, and articulate the contributions and practical implications for communication-centric devices in substation environments.

[Comment 8] Proofread for technical consistency and grammar.
Response 8. The manuscript has undergone thorough proofreading. We harmonised terminology (e.g., “apparent power”/PF), symbols and units, revised ambiguous phrasing, and corrected typographical and formatting issues in text, tables, and figure captions.

[Comment 9] Consider adding a use case or simulation scenario demonstrating HS3’s real-time advantages in a representative SA setting.
Response 9. Building a representative substation automation setting using the simulation tools for RTL development is not just a demanding verification task, but also requires a lot of processing time due to its fine resolution. Our validation approach is much more demanding than a real SA setting, as we can feed SMV packets continuously, separated only by the Ethernet minimum allowed inter-packet gap (IPG).

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I reviewed the revised version of the manuscript and found that the authors had already addressed the comments and enhanced the writing quality.

Reviewer 3 Report

Comments and Suggestions for Authors

Many thanks