Conventional Protection Research Articles

Reverse Blocking Over Current Busbar Protection Scheme Based on IEC 61850 Architecture

Substation Automation System (SAS) is currently in a matured state of technology that shall facilitate transformational changes from conventional protection scheme. IEC 61850 protocol is considered as the crux of digital SAS due to its multifunction features that include seamless communication, ability to integrate various intelligent electronic devices, potential for improved real-time condition monitoring, reliable protection, and control of critical electrical assets. Because the application of IEC 61850 in SAS is relatively new and has not fully implemented in many substations yet, further feasibility studies using multivendor equipment to assess its performance under different operating conditions is imperative. In this article, a practical reliable and efficient reverse blocking over current bus bar protection scheme based on IEC 61850 is implemented and tested. Also, a comparison of digital SAS and conventional protection scheme is presented to highlight the superiority of the former one. Experimental results attest the reliability and effectiveness of the proposed digital protection scheme along with the accuracy and security of transmitting data packets using sampled values and generic objective-oriented substation event communication protocols adopted by IEC 61850.

Effects of Conventional and Musician-Specific Hearing Protection Devices on Speech Intelligibility

(1) Background: To assess and compare speech intelligibility with conventional and universal musician-specific hearing protection devices (HPD); (2) Methods: The sample comprised 15 normal-hearing musicians of both sexes who had been professionals for more than 5 years. They underwent thorough audiological assessment and free-field audiometry to measure the attenuation levels of three HPD models (musician-specific, silicone, and foam devices). The sentence recognition thresholds in quiet (SRTQ) and noise (SRTN) were assessed with the Lists of Sentences in Portuguese. User satisfaction with musician HPD was assessed after 2 months; (3) Results: Conventional HPD had higher pure-tone mean attenuation levels than musician HPD. No statistically significant differences were found in SRTQ and SRTN between the three HPD types. However, the musician HPD had higher mean signal-to-noise ratios and percentages of correct words from sentences presented in noise than the other HPD. The answers also indicated a positive trend toward satisfaction with the musician-specific HPD; (4) Conclusions: Despite the lack of significant differences in speech intelligibility while wearing the three HPD models in either quiet or noise, the musician-specific HPD provided greater musical sound quality. This reinforces the possibility of an effective and adequate use of protection to preserve musicians’ hearing.

Studies on the potential of the basic substance chitosan in managing Podosphaera pannosa on cutting roses and Erysiphe polygoni on French hydrangea

Horticultural production systems have to move forwards to an environment-friendly and sustainable plant production. Basic substances can be added to reduce the use of synthetic plant protectant in conventional plant protection strategies. Regarding the protection of ornamental plants, less is known about the usage and behaviour of these alternative strategies and components. In our study, an infection of Podosphaera pannosa and Erysiphe polygoni in two different cultivars of cutting roses and one cultivar of French hydrangea was investigated. We studied the effect of a weekly foliar treatment of the basic substance chitosan (0.05 g/m2) compared to a water control and potassium hydrogen carbonate (VitiSan, Biofa GmbH, Münsing, Germany) in both production systems. As a result, in cutting roses as well as in French hydrangea, we found a significantly decreased infected leaf area following the use of chitosan and VitiSan compared to the water control. In both treatments, we found a stronger effect in French hydrangea, compared to roses. Results also indicate that the basic substance chitosan has to be used at a low pathogen level. We present a promising approach to reduce conventional plant protectants in ornamental plant production.

Formation of gallium coating on tungsten surface and its oxidation protection in air

To address the poor high-temperature oxidation resistance of tungsten, a new high temperature protective gallium coating (OGa) is designed in this paper. This OGa material is modified with liquid metallic gallium by a mechanical stirring process, and a mixture of GaxOy (Ga2O3 and Ga2O) and Ga is obtained. Not only does it have good flexibility and adhesion, but it can also be easily printed to form a coating on tungsten surfaces. After isothermal oxidation at 800 °C for 24 h, the weight gain of the coating sample is 0.96 mg·cm−2, much lower than that of tungsten. This is attributed to the oxidation of the gallium coating on the tungsten surface to produce a βGa2O3 layer, which prevents oxygen contact with the internal OGa and W substrates. In addition, the inherent flexibility of the intermediate layer of OGa prevents a mismatch in the coefficient of thermal expansion (CTE) between the βGa2O3 layer and the W substrate, ensuring the integrity of the coating. Gallium coatings are expected to be an alternative to conventional protection systems.

The structural and functional shift in the soil rhizosphere and raspberry shoot microbiomes underlies changes caused by phytopathogens contamination and naturalization strategies implementation

Biopreparations based on an inoculum of beneficial bacteria may become an essential tool in the prevention of fungal and fungal-like phytopathogens with cause a decrease in the yield of raspberries, especially in organic farming, in which the use of conventional plant protection products is prohibited. The research is based on a pot experiment which includes 4 different naturalization strategies and 5 different pathosystems. The application of environmental isolates of plant beneficial bacteria belonging to genera Arthrobacter, Pseudomonas, and Rhodococcus to the raspberry plant was performed in order to characterize their effect on the microbial communities surrounding the raspberry plant. The application of pathosystems consisting of fungal and fungal-like pathogens belonging to the Botrytis, Colletotrichum, Phytophthora, and Verticillium genera allowed for an analysis to be conducted with regard to the effect of naturalization treatments on microbial communities of raspberry plants infected with phytopathogens. Rhizosphere and shoots samples were subjected to a functional profiling analysis of their microbial communities with the use of Biolog® EcoPlates. Furthermore the DNA was isolated from the rhizosphere and shoots of raspberries and sequenced using the Illumina MiSeq platform. The application of a bacterial inoculum resulted in a decrease in the substrate stress index of raspberry shoots microbiota. Over 95 % of the fungal phyla found in the rhizosphere consisted of 3 phyla: Ascomycota, Mortierellomycota, and Basidiomycota. The results obtained indicated, that the application of plant beneficial bacteria to raspberry plants roots during planting, and afterwards during the watering, may be an important way of inhibiting the negative effect of plant pathogens and enhancing the functional abilities of microbial communities.

Transmission Line Protection Using Dynamic State Estimation and Advanced Sensors: Experimental Validation

This paper presents the experimental validation of a protection scheme for a transmission line based on dynamic state estimation along with the practical application of advanced sensors in this protection scheme. The scheme performs dynamic state estimation with high-frequency measurements provided by the sensors, assesses the operating condition (i.e., health) of the transmission line in real-time, and thereby determines the tripping signal whenever a fault is detected. The validation was carried out in two steps, first with simulation studies for a three-phase fault and then with the experimental implementation using a physical scaled-down model of a power system consisting of transmission lines, transformers, and loads. The simulation and validation results have shown that the scheme performs adequately in both normal and fault conditions. In the fault case with the experimental setup, the scheme could correctly detect the fault and send the trip signal to the line’s circuit breakers with a total fault clearing time of approximately 65 milliseconds which is comparable to conventional protection methods. The average processing time for a measurement sample block is 12.5 milliseconds. The results demonstrate that this scheme and the sensors would work for transmission line protection which can avoid relay coordination and settings issues.

Distance protection with fault resistance compensation for lines connected to PV plant

The output power of the inverter-interfaced photovoltaic (PV) plant has the continuous variations due to the properties of PV modules and environmental conditions. These variations fundamentally affect the performance of the conventional distance protection during nonmetallic faults. This paper proposes a positive sequence network-based distance protection scheme for the transmission lines connected to the PV plants. Different from the adaptive mho and quadrilateral characteristics, the proposed scheme is independent of PV plant parameters and fault resistance. In this method, the Thevenin equivalent parameters of the grid seen from the PV plant are calculated. Thevenin equivalent parameters are calculated using prefault current and voltage data at the local terminal, without additional costs related to the requirements of the communication channel. The obtained parameters are used in the fault resistance compensation. Furthermore, by eliminating the fault resistance effect on the relay impedance, the exact fault location is also calculated. Since the fault line impedance formula is derived only from the positive sequence network, the proposed method is applicable to different grid codes. The efficiency of the proposed scheme is evaluated on the Western System Coordinating Council (WSCC) 9-bus and IEEE 30-bus test systems. The obtained simulation results verify the validity of the proposed scheme under various fault and PV plant conditions.

Impact of Rhamnolipids (RLs), Natural Defense Elicitors, on Shoot and Root Proteomes of Brassica napus by a Tandem Mass Tags (TMTs) Labeling Approach.

The rapeseed crop is susceptible to many pathogens such as parasitic plants or fungi attacking aerial or root parts. Conventional plant protection products, used intensively in agriculture, have a negative impact on the environment as well as on human health. There is therefore a growing demand for the development of more planet-friendly alternative protection methods such as biocontrol compounds. Natural rhamnolipids (RLs) can be used as elicitors of plant defense mechanisms. These glycolipids, from bacteria secretome, are biodegradable, non-toxic and are known for their stimulating and protective effects, in particular on rapeseed against filamentous fungi. Characterizing the organ responsiveness to defense-stimulating compounds such as RLs is missing. This analysis is crucial in the frame of optimizing the effectiveness of RLs against various diseases. A Tandem Mass Tags (TMT) labeling of the proteins extracted from the shoots and roots of rapeseed has been performed and showed a differential pattern of protein abundance between them. Quantitative proteomic analysis highlighted the differential accumulation of parietal and cytoplasmic defense or stress proteins in response to RL treatments with a clear effect of the type of application (foliar spraying or root absorption). These results must be considered for further use of RLs to fight specific rapeseed pathogens.

Fault current control of MMC in HVDC-connected offshore wind farm: A coordinated perspective with current differential protection

The modular multilevel converter (MMC) based high-voltage dc (HVDC)-connected offshore wind farm (OWF) is power electronic converter dominated power system, where the conventional current differential protection may not operate effectively. Based on the basic operation principle of the current differential relay, this paper points out that the phase difference (ϕdiff) of fault currents from MMC and OWF should be limited within a specific range, i.e. (-ϕdiffmax, ϕdiffmax), to guarantee the reliable tripping of the current differential relay. Yet, the highly control-dependent fault currents from the MMC and OWF could yield an arbitrary ϕdiff that might beyond (-ϕdiffmax, ϕdiffmax), which leads to the possible malfunction of the current differential relay. To tackle this challenge, the coordinated control method of MMC is proposed to align the phase angle of its fault current with that of the OWF, such that ϕdiff ∈ (-ϕdiffmax, ϕdiffmax) can be always guaranteed, so as the reliable operation of the current differential relay. Finally, the proposed coordinated control is verified by the electromagnetic transient (EMT) simulations in PSCAD and the real-time digital simulator (RTDS).

Effectiveness of radiation protection systems in the cardiac catheterization laboratory: a comparative study

BackgroundAs numbers and complexity of percutaneous coronary interventions are constantly increasing, optimal radiation protection is required to ensure operator safety. Suspended radiation protection systems (SRPS) and protective scatter-radiation absorbing drapes (PAD) are novel methods to mitigate fluoroscopic scattered radiation exposure. The aim of the study was to investigate the effectiveness regarding radiation protection of a SRPS and a PAD in comparison with conventional protection.MethodsA total of 229 cardiac catheterization procedures with SRPS (N = 73), PAD (N = 82) and standard radiation protection (N = 74) were prospectively included. Real-time dosimeter data were collected from the first operator and the assistant. Endpoints were the cumulative operator exposure relative to the dose area product [standardized operator exposure (SOE)] for the first operator and the assistant.ResultsFor the first operator, the SRPS and the PAD significantly decreased the overall SOE compared to conventional shielding by 93.9% and 66.4%, respectively (P < 0.001). The protective effect of the SRPS was significantly higher compared to the PAD (P < 0.001). For the assistant, the SRPS and the PAD provided a not statistically significant reduction compared to conventional shielding in the overall SOE by 38.0% and 30.6%, respectively.ConclusionsThe SRPS and the PAD enhance radiation protection significantly compared to conventional protection. In most clinical scenarios, the protective effect of SRPS is significantly higher than the additional protection provided by the PAD.Graphical abstractComparison of the additional radiation protection provided by protective scatter-radiation absorbing drapes (PAD) and the suspended radiation protection system (SRPS) system over standard protection with lead aprons.

A THD-Based Fault Protection Method Using MSOGI-FLL Grid Voltage Estimator

The rapid growth of the distributed generators (DGs) integration into the distribution systems (DSs) creates new technical issues; conventional relay settings need to be updated depending on the network topology and operational mode as fault protection a major challenge. This emphasizes the need for new fault protection methods to ensure secure protection and prevent undesirable tripping. Total harmonic distortion (THD) is an important indicator for assessing the quality of the grid. Here, a new protection system based on the THD of the grid voltages is proposed to address fault events in the electrical distribution network. The proposed protection system combines the THD with the estimates of the amplitude voltages and the zero-sequence component for defining an algorithm based on a finite state machine (FSM) for the detection, identification, and isolation of faults in the grid. The algorithm employs communication lines between all the protective devices (PDs) of the system to transmit tripping signals, allowing PDs to be coordinated. A second order generalized integrator (SOGI) and multiple SOGI (MSOGI) are used to obtain the THDs, estimated amplitude voltages, and zero-sequence component, which allows for fast detection with a low computational burden. The protection algorithm performance is evaluated through simulations in MATLAB/Simulink and a comparative study is developed between the proposed protection method and a differential relay (DR) protection system. The proposed method shows its capability to detect and isolate faults during different fault types with different fault resistances in different locations in the proposed network. In all the tested scenarios, the detection time of the faults has been between 7-10 ms. Moreover, this method gave the best solution as it has a higher accuracy and faster response than the conventional DR protection system.

Unbalance compensated distance relay for active distribution networks

Integration of Distributed Energy Resources (DER) into the Active Distribution Networks (ADN) causes issues in conventional overcurrent protection. Additionally, another conventional protection, such as the distance function, has been used, but ADN characteristics require new well-fitted approaches. This paper proposes a strategy to improve conventional distance relays when applied in unbalanced distribution lines. The strategy is based on the relay’s current and voltage measurements and the line series impedance matrix. Different overhead line cases are studied considering several pole geometrical arrangements and fault types. Based on the results, the new set of equations for distance-based protection can achieve a more accurate fault impedance estimation, with a maximum error of 0.1% in the analysed situations and despite the fault conditions. The high proposal performance and the straightforward application make this proposal suitable for the nowadays ADN protection.

Assessment of the Performance of Phasor-Based and Transients-Based Faulted Phase Identification Techniques in the Presence of Inverter Interfaced Resources

Faulted phase identification is one of the segments of conventional system protection that is severely vulnerable in the presence of inverter-based resources (IBR) such as Type IV wind and solar PV power plants. The work presented in this paper investigates the effect of IBRs on the conventional phasor-based faulted phase identification methods widely implemented in contemporary commercial protection relays using theoretical analysis and simulation results. Moreover, this premise is further validated by testing commercial line protection relays using hardware-in-the-loop simulations. This paper also evaluates the applicability of recently proposed transients/incremental quantities-based techniques to overcome the deficiencies of conventional methods to correctly identify the faulted phase in systems with IBRs through real-time and control hardware-in-the-loop simulations. Comparisons with commercial relays show that transient/incremental quantities-based methods are more suitable for systems with a high penetration of IBRs.

Harmonic Dual-Setting Directional Overcurrent Protection for Inverter-Based Islanded Microgrids

Limited fault currents in inverter-interfaced islanded microgrids impose immense challenges on conventional overcurrent protection schemes. This paper proposes a sensitive and selective protection scheme for islanded microgrids using a third harmonic voltage generated by inverter-interfaced distributed generators (IIDGs). The generated harmonic voltage results in a harmonic layer formed during short-circuit faults and is decoupled from the fundamental fault current, i.e., limited by IIDGs. Further, the generated harmonic voltage is adaptively adjusted based on fault severity to enhance protection sensitivity and obtain a universal set of relays’ settings. The proposed protection scheme utilizes harmonic directional overcurrent relays (HDOCRs) equipped with a dual-setting time-current-voltage setting that sense the generated harmonic voltages and currents at the relay location to ensure optimal protection coordination (OPC) of islanded microgrids. The OPC with the proposed dual-setting is formulated as a constrained nonlinear program to determine the optimal forward and reverse relays’ settings. The proposed scheme is tested on the Canadian benchmark urban distribution system and compared to the conventional protection scheme, which relies only on a single time-current-voltage trip characteristic. The results ensure the ability of the proposed scheme to protect islanded microgrids without communication and its capability to reduce relays’ operation times.

Efficacy of L-shaped Shielding in Interventional Radiology by Transradial Approach and Consideration of Methods for Appropriate Use

The present study investigated how effective an L-shaped shield was, depending on its position, in reducing a doctor's exposure to radiation during catheterization to access the transradial approach (TRA). The shield's effectiveness was evaluated by measuring the air kerma where the doctor stood under four conditions: with and without the shield, and with and without the shield in conjunction with conventional protection. To enable the shield to be positioned correctly in clinical practice, an illustrated instruction decal affixable to the shield's doctor-facing surface was produced, and the effectiveness of the decal was verified by means of a crossover test in which, as subjects of the study, different nurses set up the shield with and without the decal affixed to it. In the test, in which a human body phantom was used, the C-arm set at the PA angle, and the shield positioned 10 cm from the axilla of the phantom, the shield's effectiveness at 100 cm, 130 cm, and 160 cm above the floor where the doctor stood was 55%, 77%, and 47%, respectively. The effectiveness increased when the shield was positioned closer to the axilla. A significant difference in the positioning of the shield by the subjects was observed depending on whether or not the decal was affixed ( p<0.05, Wilcoxon signed-rank test), indicating that the use of the decal improved the positioning. It was concluded that, positioned correctly, the shield could effectively reduce the doctor's exposure to radiation during TRA.

A Negative Sequence Admittance Based Algorithm for Identifying Fault Direction in the Presence of Inverter Based Resources

Ever increasing integration of renewable resources into contemporary power systems has imposed a unique set of challenges for system protection. Effectiveness of techniques based on conventional system protection theory has long been questionable in protecting power systems with higher penetration of inverter-based resources (IBRs). Fault direction identification is one of the commonly affected protection functions in the presence of IBRs. This paper presents a novel algorithm to correctly identify fault direction using negative sequence admittance measurements. The proposed technique is robust and reliable and yields better results in comparison to conversional techniques in presence of IBRs. In addition, its operation is simple and can be conveniently incorporated into a modern digital relay.

Study on Selective Insulation On-line Monitoring Technology for Mine Power Network

In this paper, by studying the change rule of zero sequence voltage when single-phase leakage occurs, the detection method of insulation decline of mine cables is studied, especially the additional low-frequency signal sampling technology of power cables. Combined with the conventional leakage protection technology, the online monitoring equipment and supporting software for the insulation parameters of power cables are developed to realize the online monitoring of the insulation of each branch cable of the mine low-voltage power supply system and achieve the purpose of selective leakage protection.

Instant_Anonymity: A Lightweight Semantic Privacy Guarantee for 5G-Enabled IIoT

Data publication and sharing are critical components of assessing network infrastructures in the Internet of Things for quality-of-service enhancement. Especially, the advancement in communication technology (e.g., 5G/6G) enables the improvement of the current bottlenecks in the Industrial Internet of Things. Recent approaches remove raw data and their source to achieve a privacy guarantee. However, the data are already anonymized; these still reveal the victim’s extra information using linkage attacks. When data are updated and combined or noise is introduced as part of conventional privacy protection approaches, such as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$k$</tex-math></inline-formula> -anonymity, l-diversity, or differential privacy, the usefulness of the released data is diminished, however, posing data utility and computation constraints. In recent years, lightweight privacy-preservation techniques have been proposed for these reasons. However, most of the focus is on syntactic privacy instead of semantic privacy guarantee. Therefore, this article proposes a lightweight semantic privacy-preservation framework for maintaining privacy with high utility efficiency. The proposed paradigm ensures semantic privacy by combining probabilistic random sampling with Instant_Anonymity. Compared to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$k$</tex-math></inline-formula> -anonymity, the suggested model demonstrates improved data utility with lower utility errors of 0.00036 and 0.41 for Kullback–Leibler divergence and query error, respectively. The classification accuracy is improved by 0.2%. In addition, the proposed approach is simpler to implement in computation time than the existing state-of-the-art lightweight privacy-preserving strategies.

APPLICATION OF SILK PROTEIN HYDROLYSATE AS A POTENT ANTI-CORROSIVE AGENT FOR MILD STEEL IN HCl SOLUTION

The study focuses on broadening the application of Silk Protein Hydrolysate (SPH) towards conventional metal protection of metallic materials. The inhibitory potentials of SPH against corrosion of mild steel in 1 N HCl media are analyzed through weight loss, electrochemical, and surface morphological techniques. The assessment of the inhibitor effectiveness, kinetic and thermodynamic variables was done at the temperature of 303 – 333 K. The studies exhibited superior anti-corrosion efficacy of 93 % for 10 ppm SPH at 303 K and good maintenance in corrosion control is seen with temperature rise. The SPH assimilation at the metal surface follows the Langmuir adsorption model with free energy values lower than -20 KJ/mol. Potentiodynamic polarization studies evince the mode of corrosion protection to be mixed overall with cathodic predominance. Electrochemical impedance spectroscopy describes the resistive and capacitive behavior through Rct and Cdl values signifying the physical barrier prevailing on the metal surface. Surface monitoring through SEM-EDS reveals the firm adherence of SPH to the metallic surface, XRD study characterizes the corrosion products formed in the process. The roughness variables derived from AFM imaging remark the stable protective layer formed by the SPH molecules. The defensive film formed smoothes the metal surface leading to an enhanced water contact angle.

Optimal Bottleneck-Driven Deep Belief Network Enabled Malware Classification on IoT-Cloud Environment

Cloud Computing (CC) is the most promising and advanced technology to store data and offer online services in an effective manner. When such fast evolving technologies are used in the protection of computer-based systems from cyberattacks, it brings several advantages compared to conventional data protection methods. Some of the computer-based systems that effectively protect the data include Cyber-Physical Systems (CPS), Internet of Things (IoT), mobile devices, desktop and laptop computer, and critical systems. Malicious software (malware) is nothing but a type of software that targets the computer-based systems so as to launch cyber-attacks and threaten the integrity, secrecy, and accessibility of the information. The current study focuses on design of Optimal Bottleneck driven Deep Belief Network-enabled Cybersecurity Malware Classification (OBDDBN-CMC) model. The presented OBDDBN-CMC model intends to recognize and classify the malware that exists in IoT-based cloud platform. To attain this, Z-score data normalization is utilized to scale the data into a uniform format. In addition, BDDBN model is also exploited for recognition and categorization of malware. To effectually fine-tune the hyperparameters related to BDDBN model, Grasshopper Optimization Algorithm (GOA) is applied. This scenario enhances the classification results and also shows the novelty of current study. The experimental analysis was conducted upon OBDDBN-CMC model for validation and the results confirmed the enhanced performance of OBDDBN-CMC model over recent approaches.