Conventional Protection Research Articles

Rapid Determination of RNA Modifications in Consensus Motifs by Nuclease Protection with Ion-Tagged Oligonucleotide Probes and Matrix-Assisted Laser Desorption Ionization Mass Spectrometry.

The reversible and substoichiometric modification of RNA has recently emerged as an additional layer of translational regulation in normal biological function and disease. Modifications are often enzymatically deposited in and removed from short (~5 nt) consensus motif sequences to carefully control the translational output of the cell. Although characterization of modification occupancy at consensus motifs can be accomplished using RNA sequencing methods, these approaches are generally time-consuming and do not directly detect post-transcriptional modifications. Here, we present a nuclease protection assay coupled with matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) to rapidly characterize modifications in consensus motifs, such as GGACU, which frequently harbor N6-methyladenosine (m6A). While conventional nuclease protection methods rely on long (~30 nt) oligonucleotide probes that preclude the global assessment of consensus motif modification stoichiometry, we investigated a series of ion-tagged oligonucleotide (ITO) probes and found that a benzylimidazolium-functionalized ITO (ABzIM-ITO) conferred significantly improved nuclease resistance for GGACU targets. After optimizing the conditions of the nuclease protection assay, we applied the ITO and MALDI-MS-based method for determining the stoichiometry of GG(m6A)CU and GGACU in RNA mixtures. Overall, the ITO-based nuclease protection and MALDI-MS method constitutes a rapid and promising approach for determining modification stoichiometries of consensus motifs.

Microgrid Fault Detection and Classification Based on the Boosting Ensemble Method With the Hilbert-Huang Transform

In this paper, a sequential ensemble of intelligence-based methods is used for fault detection and classification in microgrids. The proposed scheme is recommended because of the impracticality of conventional fault detection and protection due to microgrid dynamic behavior and dependency of traditional methods on faults current level or impedance. These methods use the collective decision of learners to increase their accuracy. This is done by distributing the knowledge among the classifiers. The proposed ensemble method is called Brownboost. Its main advantage over its counterparts is that it uses a nonconvex optimization method. This makes it robust to overfitting and applicable and practical for a real-world noisy or misclassified data. In addition, a signal processing method called the Hilbert-Huang transform was chosen for feature extraction from signals transient behavior to reduce the noise sensitivity. In this method, current difference of the both ends of line is selected to decompose various types of adaptive basis signal processing method. The results are validated in IEC test microgrid with various noise penetration level and synchronization delays. Compared to traditional strong classifiers, this method is easy to tune and program and is robust to overfitting. Moreover, it can be justified for real-world imperfect data.

Service Chain Provisioning With Sub-Chain-Enabled Coordinated Protection to Satisfy Availability Requirements

This paper proposes a sub-chain-enabled coordinated protection model for the availability-guaranteed service function chain (SFC) provisioning, which considers the availability of each component to constitute an SFC, including links and VNFs. Unlike conventional protection models providing certain protection for the whole chain, the proposed model configures sub-chains for each SFC and provides proper protection for each sub-chain to achieve the required availability in a cost efficient way. We formulate the proposed model as an optimization problem to minimize the deployment cost. A game approach is presented to tackle the problem. The numerical results show that the proposed model outperforms the conventional ones in terms of deployment cost; the game approach has scalability of tackling the proposed model as the problem size increases.

A multi-scale dual-stage model for PV array fault detection, classification, and monitoring technique

The output generated by photovoltaic arrays is influenced mainly by the irradiance, which has non-uniform distribution in a day. This has resulted in the current-limiting nature and nonlinear output characteristics, and conventional protection devices cannot detect and clean faults appropriately. This paper proposes a low-cost model for a multi-scale dual-stage photovoltaic fault detection, classification, and monitoring technique developed through MATLAB/Simulink. The main contribution of this paper is that it can detect multiple common faults, be applied on multi-scale photovoltaic arrays regardless of environmental conditions, and be beneficial for photovoltaic system maintenance work. The experimental results show that the developed algorithm using supervised learning algorithms mutual with k-fold cross-validation has produced good performances in identifying six common faults of photovoltaic arrays, achieved 100% accuracy in fault detection, and achieved good accuracy in fault classification. Challenges and suggestions for future research direction are also suggested in this paper. Overall, this study shall provide researchers and policymakers with a valuable reference for developing photovoltaic system fault detection and monitoring techniques for better feasibility, safety, and energy sustainability.

A Memory Based Current Algorithm for Pole-to-Pole Fault Detection in Microgrids

Abstract: The world’s growing attention to sustainable energy and development can be causal to the recently observed disrupt in the existing global power system networks. Moreover, an additional incentive towards this change are the challenges associated with the traditional power grid, including its rigid structure, aging architecture, and ecologically profligate nature. Modern power systems have observed a rapidly growing trend of decentralized energy generation in the recent past. A prominent structure incorporating decentralized energy generation and renewable energy are microgrids. While microgrids promote on-site generation and distributed energy resources (DERs), their unique characteristics of bidirectional flow of power, renewable generational intermittency, and varying levels of current causes challenges uncommon to the traditional grid. One of the vital challenges associated with microgrids is the protection of microgrids against faults and disturbances that can cause impairment to life and property. Conventional protection algorithms are ineffective in protecting the system from faults due to the unconventional topology of the microgrid. This paper attempts to contribute to work in the sector related to the protection of microgrids. This paper presents the pole-to-pole fault analysis of a hybrid photovoltaic system and presents a current based algorithm for the detection of DC pole-to-pole faults in the system under study. The protection algorithm is further verified on a hybrid Photovoltaic-Wind-Battery microgrid. Keywords: DC Faults, Hybrid Microgrids, Power Systems, Protection Algorithm, DERs

Back-Up Protection Scheme for Series-Compensated Transmission Line Connected to Wind Farm

Series compensation poses serious challenges to the protection schemes of transmission lines (TLs). Moreover, with the penetration of distributed generation (DG), the conventional protection schemes fail to detect the fault and identify the faulty phase as the backfeed currents from the DG units mask the faulty phase. This work presents an algorithm for the protection of series-compensated TLs (SCTL) integrated with wind farms. The algorithm uses the phase difference between the positive sequence currents at the two ends of the TL to discriminate internal and external faults. The faulty phase for internal fault is identified from the difference in complex power at the two ends of the TL. Extensive simulations with several fault and system parameters assess the reliability and applicability of this technique.

Impact and challenges of conventional protection solutions in wind farm connected grids

Impact and challenges of conventional protection solutions in wind farm connected grids

Transient power polarity based fault detection in DC microgrid with localized backup scheme

Increasing energy demand and the proliferation of renewable energy sources inflicts new challenges to the conventional protection and control methodologies. Hence, a high speed, precise and reliable protection scheme is required for modern power system. In this paper, a novel protection scheme based on the characteristics of transient power is proposed for DC microgrid in grid-connected and islanded mode of operation. The proposed scheme incorporates primary as well as localized backup protection scheme. The primary protection utilizes the polarity of transient power determined at both ends of the cable under different fault conditions to discriminate between internal and external faults. The primary protection scheme doesn’t require high speed communication and synchronous data. However, in case of a communication link failure, primary protection may also fail to detect a fault; hence a localized backup protection scheme based on the change in average transient power observed at either end of the cable under different operating conditions is used to isolate the faulty section. The effectiveness of the proposed scheme is validated by simulating different fault conditions such as internal and external faults along with system transients such as AC side faults, noisy environment, load variation, DG outage and generation uncertainties due to change in solar irradiance and wind speed. Further, the proposed scheme is also validated on a scaled-down hardware setup in the laboratory, which illustrates the effectiveness and robustness of the proposed protection scheme.

A novel fault detection and classification scheme for DC microgrid based on transient reactor voltage with localized back-up scheme

Integration of renewable energy sources in distribution system inflicts new challenges to the conventional protection scheme by substantially changing the amplitude and direction of fault current. In this paper, a novel protection scheme for DC microgrid based on the characteristics of reactor voltage during transient operation in both grid-connected and islanded mode of operation is proposed. The proposed protection scheme incorporates both primary as well as localized back-up protection scheme. In order to detect and classify faults, primary protection scheme utilizes the polarity of the transient reactor voltage at both ends of the cable under different operating conditions. As the primary protection uses the polarity of reactor voltage at both ends, thus the proposed scheme doesn’t require high speed communication and synchronous data. In case of communication failure, localized back-up protection scheme based on the change in reactor voltage at one end of the cable is used to identify the faulty section. The efficacy of the proposed scheme is verified against various internal and external faults along with system transients such as AC side faults, load variation, DG outage, noisy environment and generation uncertainties due to change in solar irradiance and wind speed. Finally, a scaled down hardware setup is used to validate the proposed protection scheme, which further illustrates the feasibility and reliability of the proposed protection scheme.

Adaptive and Optimal Overcurrent Protection of Wind Farms With Improved Reliability

This article presents a new adaptive and optimal overcurrent protection for large-scale wind farms using hybrid grey wolf optimizer and rule-based fuzzy logic controller (GWO-FLC) scheme. The proposed GWO-FLC based adaptive protection scheme overcomes the limitation of conventional protection scheme that suffers from maloperation of relays that damages the power components in the system during fault. Furthermore, due to the intermittent nature of wind, the generated current feeding the grid during extreme high and low wind speeds creates a significant difference in magnitudes of the generated current. Thus, the existence of only one group of settings for the overcurrent relays (OCRs) would cause drastic miscoordination and false tripping during fault. In order to test the performance of the proposed GWO-FLC scheme, several OCRs based on standard Schweitzer Engineering Laboratories industrial protection relay (SEL-751) are developed in MATLAB/Simulink. A large-scale wind farm model is also developed to perform fault analysis, relay setting, and coordination calculation. The GWO is implemented to attain optimal OCR coordination for the defined quadruple group settings for all relays, and the FLC is developed to provide adaptive feature for the relays so that the OCR group settings for each relay are intelligently updated according to the variation of wind speed. Finally, in a laboratory environment, the proposed protection scheme is implemented in real time using field-programmable gate array DE2-115 board equipped with Cyclone IV-E device (EP4CE115F29C7). It is found from both simulation and experimental results that the performance of the proposed hybrid GWO-FLC is robust, reliable, efficient and extremely satisfactory.

Coastal Protection Using Integration of Mangroves with Floating Barges: An Innovative Concept

Mangroves and moored barges are used individually for coastal protection and beach restoration. This conceptual paper discusses about the integration of mangroves with moored floating barges for coastal protection. The concept involves towing of a barge to a particular location, mooring it to the seafloor and planting mangroves along the shore or beach. The barges will be unmoored and towed away once the mangroves attain certain growth and are well rooted in the soil. Mangroves can protect the beach from incoming waves using their roots and branches. The incoming waves can be reduced by 50% to 99% using mangroves of 500 m width. Mangroves have a life span of 20–100 years, and they do not need any yearly maintenance as do any other conventional coastal protection measures. Mangroves are considered as soft coastal protection structures and are environmentally friendly. Mangroves will also improve the aesthetic appearance of the beach. This paper discusses about some of the research methodologies for the development of the barge-assisted mangroves coastal protection method. The dimensions of the barge, gap width between the moored barges and the environmental condition at the location determines the performance of the barge-assisted mangroves coastal protection method. The gap width between the barges, draft of the barge and breadth of the barge influence the resonant frequency of the fluid between the barges. The shielding effect of the floating barges can be used for other applications, such as berthing of ships and growing living shorelines using oysters, rocks, sand, plants, coir, etc. for coastal protection.

Design and Development of Superimposed Directional Comparison Protection Scheme

To achieve the UK Net Zero future by 2050, National Grid needs to integrate significantly more renewable generation into the power grid. This increases the level of harmonics, reduces system inertia and adversely affects the fault level and the performance of existing protection relays. One solution to the protection problem is the use of new types of protection that use the change in the voltage and current caused by the fault, often referred to as a superimposed or incremental based protection technique. This paper describes how a superimposed directional comparison protection scheme performed when applied to a reduced section of the full UK National Grid network and relates this to the operating performance of traditional protection. Tests are performed using the simulators DIgSILENT and RelaySimTest configured with different source levels, fault types, fault locations and fault resistances. Results show the superimposed based protection scheme achieves faster fault detection and tripping than conventional protection and is capable of detecting higher resistive faults on networks where the source capacities vary from strong to weak.

A Comprehensive Review of Microgrids, Control Strategies, and Microgrid Protection Schemes

For the greater part of a century, the world has moved to sustainable energy production, with increased dependence on renewable energy resources to meet growing energy demand. Reserves of conventional sources are rapidly depleting, with an environmental crisis due to profligate consumption. Distributed generation through renewable sources and microgrids have proved as sustainable alternatives. Microgrids provide versatile topologies with dispersed generation and provision for expansion. However, the nonconventionality of microgrids pose challenges and the conventional control and protection strategy have proven unsuitable. This paper attempts to be a review of microgrids, challenges, and existing protection schemes. The first segment of this paper presents the definition and overview of the microgrid market scenario. The next segment discusses microgrid classification and control strategies, following which challenges, and protection schemes are reviewed. The paper concludes with an overview of relay coordination, optimization algorithms, and an outline of few international microgrid standards and codes.

Change detection filter technique-based fault analysis of HVDC transmission line

PurposeThis research paper aims to investigate the change detection filter technique with a decision tree-based event (fault type) classifier for recognizing and categorizing power system disturbances on the high-voltage DC (HVDC) transmission link.Design/methodology/approachA change detection filter is used to the average and differential current components, which detects the point of fault initiation and records a change detection point (CDP). The half-cycle differential and average currents on both sides of the CDP are sent through the signal processing unit, which produces the respective target. The extracted target indices are sent through a decision tree-based fault classifier mechanism for fault classification.FindingsIn comparison with conventional differential current protection systems, the developed framework is faster in fault detection and classification and provides great accuracy. The new technology allows for prompt identification of the fault category, allowing electrical grids to be restored as quickly as possible to minimize economic losses. This novel technology enhances efficiency in terms of reducing computing complexity.Research limitations/implicationsSetting a threshold value for identification is one of the limitations. To bring the designed system into stability condition before creating faults on it is another limitation. Reducing the computational burden is one of the limitations.Practical implicationsCreating a practical system in laboratory is difficult as it is a HVDC transmission line. Apart from that, installing rectifier and converter section for HVDC transmission line is difficult in a laboratory setting.Originality/valueThe suggested scheme’s importance and accuracy have been rigorously validated for the standard HVDC transmission system, subjected to various types of DC fault, and the results show the proposed algorithm would be a feasible alternative to real-time applications.

A novel anti-oxygen composite coating and its corrosion resistance mechanism

To obtain environmentally friendly and highly efficient anticorrosive coatings, we elaborately designed novel filler with multiple protections. In this system, we used CeO2 nanorods modified micron-scale MMT (CeO2&MMT) as the filler to fabricate epoxy (EP) coating at steel. For the first time, CeO2 with oxygen vacancies was designed at the MMT sheet, greatly improving the corrosion resistance of EP coating. The impedance modulus of CeO2&MMT/EP coating maintained 1011 Ω·cm2 after 200 days in 3.5 wt% NaCl solution. Therefore, the work demonstrates that the novel passivation mechanism makes the CeO2&MMT/EP coating a very promising alternative for the conventional protection system.

Stator earth fault detection & evaluation of delaminated stator bar ground wall-insulation of generator G-4 of HPP Chhukha – A case study

Protective devices are employed to monitor and isolate the faulty equipment whenever faults occur in the power system. In the generator protection system, a conventional stator earth fault protection, which is based on residual over voltage (aka neutral voltage displacement) principle, is observed to be inadequate. The paper thus, discusses on how helpful a modern approach of 100% stator earth fault protection scheme is, and proven effective in generator G- 4 of Chhukha Hydropower Plant (CHP). Also, to assess the health of stator windings, insulation resistance (IR) measurement is the foremost test that needs to be performed to qualify for go- ahead with other insulation tests. HV DC ramp and tan ẟ tests are not uncommon as the tests have been proven useful in evaluating the condition of the groundwall insulation of stator coils. Therefore, this paper also illustrates on investigation and analysis of the test results obtained for a bar, suspected to have groundwall insulation breakdown, due to a number of factors. The test results obtained are compared with that of the other test specimens.

Features of the conventional protection of cultural heritage at the level of the Council of Europe

The aim of the work is to identify and disclose the distinctive features of the regulation of the protection of cultural heritage in accordance with the main conventions of the Council of Europe in this area, which are the subject of the study. The methodological basis of the article is the methods of deduction, induction, analysis, synthesis, formal-logical, descriptive, system-structural, historical, comparative, formal-legal methods. The paper identifies problems related to the protection of cultural heritage that exist on a global scale and at the level of Russia, describes the efforts of the international community to solve such problems. The definition of cultural heritage is given. The list of all international treaties adopted under the auspices of the Council of Europe, which in one way or another affect the issues of cultural heritage, is given, the greatest importance of five of these conventions is argued. The features of the conventional protection of cultural heritage at the level of this international organization, highlighted on the basis of the study of these international treaties, are considered. The author points out such features as paying special attention to human rights; attaching great importance to the participation of civil society and the public in activities related to cultural heritage; the frequent absence of its explicit division into tangible and intangible heritage, etc. Taking into account the highlighted characteristic features of the States parties to the most significant international treaties mentioned above can contribute to improving the effectiveness of their application of these conventions - not only individually, but also in a complex. This also applies to Russia. The author identifies areas related to the features of the convention protection of cultural heritage at the level of the Council of Europe, on which it may be advisable for Russia to intensify its activities. The scientific novelty of the article is determined by the above-mentioned conclusions and recommendations of the author. It is also expressed in the disclosure of some of the above-mentioned features of the regime of the main conventions of the Council of Europe in the field of protection of cultural heritage, for example, paying special attention to human rights.

Sustainable Deep Learning at Grid Edge for Real-Time High Impedance Fault Detection

High impedance faults (HIFs) on overhead power lines are known to cause fires. They are difficult to detect using conventional protection relays because the fault current is insufficient to cause tripping. The delay in detecting HIFs can result in severe bushfires and energy losses; hence a high throughput, low latency detection scheme needs to be developed for HIF detection. Moreover, the complexities associated with HIF detection demands signal processing techniques combined with artificial intelligence to achieve higher detection accuracy. This paper proposes a sustainable deep learning-based approach in an edge device, that can be mounted on top of a power pole to detect HIFs in real-time. Data acquisition, feature extraction, and deep learning based fault identification are performed in an embedded edge node to achieve higher throughput, reduced latency as well as offload the network traffic. Furthermore, optimization techniques such as hardware parallelism and pipelining are adapted to achieve real-time fault identification on edge devices while ensuring the efficient usage of its limited resources. Real-time implementation of the proposed system is validated through laboratory experiments and the results demonstrate the suitability of edge computing to detect HIFs in terms of reduced detection latency (115.2 ms) and higher detection accuracy (98.67 percent).

Clinical Research into Treating Unexplained Recurrent Spontaneous Abortion during Early Pregnancy with the Qing Yi Tiao Mian Formula

ObjectiveThe present study aims to analyze the clinical effect of the Qing Yi Tiao Mian (QYTM) formula on unexplained recurrent spontaneous abortion (URSA) during early pregnancy and the immune balance of T lymphocytes. MethodsWith their consent, 45 patients with URSA in weeks 4–9 of pregnancy were separated into three groups, i.e., the conventional fetal protection (n = 15), prednisone treatment (n = 10), and QYTM formula treatment (n = 20) groups. These patients received treatment once they had been diagnosed with an intrauterine pregnancy. The conventional fetal protection group was given progesterone (20 ∼ 40 mg daily injection) for four weeks. The prednisone treatment group was given progesterone (20 ∼ 40 mg daily injection) + prednisone (5 mg/d) for four weeks. The QYTM formula treatment group was given progesterone (20 ∼ 40 mg daily injection) + QYTM formula (one dose per day) for four weeks. In addition, women who had previously had a normal pregnancy were enrolled as a control group (n = 18). The success rate of the pregnancy in the first trimester was observed in each group, and the proportion of T lymphocytes in the peripheral blood before and after treatment was recorded. ResultsAmong the 20 patients with URSA in the QYTM formula treatment group, 19 remained pregnant. Thus, the success rate during early pregnancy was 95%, which was significantly higher than the conventional fetal protection (53.33%) and prednisone treatment (70%) groups. The CD8+ T and natural killer (NK) cells population in the URSA groups was higher compared with the control group (P < 0.01). The QYTM formula treatment significantly decreased the ratio of CD8+ T lymphocytes (P < 0.01) and NK cells (P < 0.01). ConclusionThe QYTM formula significantly decreased the spontaneous abortion rate in patients with URSA during early pregnancy. The mechanism may be closely related to the inhibition of the killer lymphocytes’ proliferation by CD8+ T lymphocytes and NK cells.

HUBUNGAN PENGETAHUAN DENGAN MINAT DALAM PENGGUNAAN MENSTRUAL CUP PADA MAHASISWI UNIVERSITAS NASIONAL JAKARTA

Background: Menstrual cup is an internal device for menstrual flow and is claimed to be an environmentally friendly alternative to conventional menstrual sanitation protection. Women's knowledge about environmentally friendly menstrual cups is important for every woman's attention in the concept of menstrual hygiene and helps in realizing the Sustainable Development Goals (SDGs) in 2030. However, inappropriate knowledge makes menstrual cups less desirable. Aim: this study aimed to analyze the relationship between knowledge and interest in the use of menstrual cups. Methods: the method was a cross sectional approach. The sample in this study was 88 nursing students at the National University of Jakarta through accidental sampling technique. The variables analyzed were the level of knowledge and interest of female students. The research instrument used was a knowledge and interest questionnaire. Data were analyzed with Mann Whitney with p=0,05. Results: Respondents in this study had a good level of knowledge (54.6%) and had no interest in the use of menstrual cups (78.4%). Based on the results of the Mann Whitney test, the P value obtained is P = 0.120 &gt; 0.05. Conclusion: There was no relationship between knowledge about menstrual cups and interest in using menstrual cups.Keywords : Menstrual Cup; Interest; Knowledge