Intelligent Electronic Devices Research Articles

Three-dimensional layered multifunctional carbon aerogel for energy storage and pressure sensors

Carbon aerogel has a broad application prospect in various intelligent electronic devices. However, due to the complex preparation process and poor mechanical properties of carbon aerogel, its practical application was seriously affected. Therefore, in this study, a low-energy bidirectional freezing method was designed, using natural renewable cellulose nanofibers (CNF) and chitosan (CS) as biological matrix, and graphene oxide (GO) as conductive filler to successfully prepare a high-performance multi-functional carbon aerogel. Its ordered three-dimensional sheet microstructure is conducive to stress transfer and electron transfer. The test results show that the carbon aerogel has a large specific surface area (622.79 m2/g) and can withstand 80 % high compressive strain. The carbon aerogel electrode material showed high specific capacitance in 3 M KCl electrolyte in the three-electrode system (299 F/g at 1A/g). The assembled symmetric solid-state supercapacitors were tested in a two-electrode system with excellent area-specific capacitance (381.8 mF/cm2 at 1.8 mA/cm2) and cycle stability (10,000 cycles, capacitance retention rate of 86.2 %). In addition, the carbon aerogel exhibits an excellent linear sensitivity of 25.2 kPa−1, which can be assembled into pressure sensors to monitor human biological signals such as fingers, wrists and throat in real time. These excellent properties enable carbon aerogels to be used in energy storage devices and wearable electronics.

The Effects of Supraharmonic Distortion in MV and LV AC Grids.

Since the integration of electronic devices and intelligent electronic devices into the power grid, power quality (PQ) has consistently remained a significant concern for system operators and experts. Maintaining high standards of power quality is crucial to preventing malfunctions and faults in electric assets and connected loads. Recently, PQ studies have shifted their focus to a specific frequency range, previously not considered problematic-the supraharmonic 2 kHz to 150 kHz range. This range is not populated by easily recognizable harmonic components of the 50 Hz to 60 Hz mains fundamental, but by a combination of intentional emissions, switching non-linearities and byproducts, and various types of resonances. This paper aims to provide a detailed analysis of the impact of supraharmonics (SHs) on power network operation and assets, focusing on the most relevant documented negative effects, namely power loss and the heating of grid elements, aging of dielectric materials, failure of medium voltage (MV) cable terminations, and interference with equipment and power line communication (PLC) technology in particular. Under some shareable assumptions, limits are derived and compared to existing ones for harmonic phenomena, providing a clear identification of the primary issues associated with supraharmonics and suggestions for the standardization process. Strictly related is the problem of grid monitoring and assessment of SH distortion, discussing the suitability of normative requirements for instrument transformers (ITs) with a specific focus on their accuracy.

Physically crosslinked polyvinyl alcohol, phytic acid and glycerol hydrogels for wearable sensors with biocompatibility, antimicrobial stability and anti-freezing

Portable, miniaturized, intelligent and flexible electronic devices are more and more widely used in life areas. Conductive hydrogels with remarkable ion transport capabilities and tunable mechanical properties could be emerging materials for sensing devices. However, most of conductive hydrogels do not have antimicrobial activity, leading to microbial infections for human. Herein, a hydrogel with noteworthy biocompatibility, antimicrobial stability, anti-freezing, and anti-fatigue properties was designed and developed by introducing polyvinyl alcohol, phytic acid, and glycerol. Phytic acid and PVA formed hydrogen bonds by physically cross-linking, improving the fatigue resistance and toughness of the hydrogel. The hydrogel exhibited bacteriostatic zone against for Escherichia coli as well as Bacillus subtilis, and displayed antibacterial stability within 7 days. Hydrogels appeared distinguished biocompatibility due to the absence of allergic reactions in mouse subcutaneous tissue within 14 days. Hydrogels as sensors could monitor deformational movements such as speech and joint bending. Thus, hydrogels have the potential to be used as antimicrobial materials in medical applications such as implantable sensors and clinical information interventions.

Reliability assessment applied in the design of an industrial substation in the context of Industry 4.0

Incorporating Industry 4.0 concepts into substation automation systems (SASs) enables the achievement of coordinated, fast, and selective protection systems. In this context, this work presents a reliability assessment applied in an industrial substation of a textile company within the framework of Industry 4.0. The Markov chain models both equipment and protection systems, while fault tree analysis allows for analyzing the alternative design scenarios in detail. The TopEvent software version 1.2.3 is used to provide accurate diagnosis using the min-max method. While enhancing selectivity with circuit breakers decreases failure severity, it concurrently increases contingency probability, not necessarily leading to higher reliability. Notably, adopting IEC 61850-based logical selectivity proves more reliable than time coordination, improving the system resilience with load shedding. With support from real-time communication between intelligent electronic devices (IEDs), this approach facilitates reliability improvement, particularly in severe contingencies.

DEVELOPMENT OF DIGITAL SUBSTATION CONSTRUCTION TECHNOLOGIES.

The development of technologies for the construction of digital substations is discussed in the article. The construction of a digital substation provides the following advantages. There are increasing the reliability of the equipment's functioning; reducing the costs of operating the equipment; increasing the efficiency of the use of the main equipment. Modern information technologies and innovative approaches to solving the tasks of automation and management of power facilities, which allow creating new type substations, have been studied. The principle of interaction of digital substation equipment is given. The differences between digital substations and analog substations are shown. The principle of operation of classical and digital substations is presented. The international experience of implementing digital substations is described. Digital substation is one of the basic technologies of Smart Grid. The basis of the construction of a digital substation is the replacement of numerous connections made by wires for the exchange of traditional analog and discrete signals with a unified exchange of digital messages, which provide the possibility of distributed implementation of the functions of the substation automation system and full functional compatibility of intelligent electronic devices of various manufacturers. The concept of "Intelligent" transformer is disclosed. A step-by-step transition to a digital substation is presented.

Centralized event-based protection based on communication infrastructure of medium voltage direct current network

Direct current (DC) distribution systems play a crucial role in integrating various DC systems, renewable energy sources, and power loads. Single-ended protection methods are inadequate for ensuring high-speed selective protection due to the lack of boundary elements, while current differential protection methods can be affected by line-distributed capacitance currents. Therefore, an event-based protection scheme is proposed that uses communication infrastructure and the first derivative of the transient fault current to provide a selective protection system for Medium Voltage Direct Current (MVDC) networks. The scheme utilizes Intelligent Electronic Devices (IEDs) to transmit events to the Intelligent Protection Center (IPC) via a communication network, which compares them to identify the faulty section. The proposed protection scheme is effective in detecting and isolating faults, even under challenging network conditions, as demonstrated by simulation results on a two-terminal topology MVDC distribution network using the PSCAD/EMTDC platform.

Validation of a Simplified Method for Estimating the Harmonic Response of Rogowski Coils with the Monte Carlo Method.

The need to monitor the power network is leading to a significant increase in the number of measurement points. These points consist of intelligent electronic devices and instrument transformers (or more in general sensors). However, as the number of devices increases, so does the demand for their characterization and testing. To this end, the authors formulated a new characterization procedure that offers numerous benefits for manufacturers and system operators. These benefits include: (i) reducing testing time (thus lowering costs), (ii) simplifying the existing procedures, and (iii) increasing the number of tested devices. In this study, to complete the validation of the proposed characterization procedure, the authors performed a comprehensive uncertainty evaluation. This included the identification and analysis of the uncertainty sources, the implementation of the Monte Carlo method to obtain the statistical parameters of the quantities of interest, and the final method assessment according to the obtained results. Each step is described in detail, and the results allow one to (i) replicate the uncertainty analysis on other types of instrument transformers and (ii) implement the proposed harmonic characterization procedure with the confidence that the method is accurate, flexible, and scalable.

Microwave-Absorbing Foams with Adjustable Absorption Frequency and Structural Coloration.

Microwave-absorbing materials with regulatable absorption frequency and optical camouflage hold great significance in intelligent electronic devices and advanced stealth technology. Herein, we present an innovative microwave-absorbing foam that can dynamically tune microwave absorption frequencies via a simple mechanical compression while in parallel enabling optical camouflage over broad spectral ranges by adjusting the structural colors. The vivid colors spanning different color categories generated from thin-film interference can be precisely regulated by adjusting the thickness of the conformal TiO2 coatings on Ni/melamine foam. Enhanced interfacial and defect-induced polarizations resulting from the introduction of TiO2 coating synergistically contribute to the dielectric attenuation performance. Consequently, such a foam exhibits exceptional microwave absorption capabilities, and the absorption frequency can be dynamically tuned from the S band to the Ku band by manipulating its compression ratio. Additionally, simulation calculations validate the adjustable electromagnetic wave loss behavior, offering valuable insights for the development of next-generation intelligent electromagnetic devices across diverse fields.

Freeze polymerization to modulate transverse-longitudinal polypyrrole growth on robust cellulose composite fibers for multi-scenario signal monitoring

Novel in-situ freeze polymerization assisted layer-by-layer self-assembly method was utilized to prepare robust regenerated cellulose fiber-polypyrrole (RCF-PPy) composite fibers with high-conductivity, where transverse-longitudinal polypyrrole growth on RCF was regulated by using Lewis acid FeCl3 in crystalline ice state with the template etching and oxidation effects. The RCF-PPy3 exhibited high strength (1.01 cN/dtex) and exceptional durability, withstanding mechanical deformation, friction (100 cycles), and ultrasonic washing (50 times), addressing the issues of poor interface adhesion and conductivity stability of conductive fibers. Furthermore, the composite fiber demonstrated high electrical conductivity of 87.66 mS cm−1 and outstanding sensing performances for monitoring strain, pressure, temperature (0.34 %/°C), and humidity (0.895 %/RH). Based on RCF-PPy3, a pressure sensor was constructed as a human–machine interface electronic device, achieving sedentary reminders, fingertip information transmission, indicating great potential applications in intelligent wearable fiber electronic devices.

Large strain, tissue-like and self-healing conductive double-network hydrogel for underwater information transmission

Traditional information-transmission systems are poorly suited for rapid underwater communication because of their large size, high cost, and low flexibility, thereby inspiring the development of conductive hydrogel-based alternatives. However, the low extensibility and non-tissue-like flexibility of common hydrogels limit their applications in wearable devices for underwater use. As such, a self-healing double-network hydrogel with a large maximal strain (>1200 %), high conductivity (3.61 S m−1) and fatigue resistance, and tissue-like Young’s modulus (<20.4 kPa) was prepared by freeze–thaw and solvent-replacement methods using polyvinyl alcohol and sodium alginate as the raw materials. In addition, the suitability of the resulting self-healing hydrogel for land and underwater applications, including sensing, communication, and energy collection, was demonstrated. The developed material enabled the (i) effective monitoring of multiple human physiological activities on land and (ii) highly consistent real-time underwater information transmission based on the use of the international Morse code at reasonable water temperatures (0–25 °C) and frequencies (1–5 Hz). Thus, this study presents a strategy for the development of soft materials as components of intelligent underwater electronic devices.

Study on Reliability of PACSs with Integrated Consideration of Both Basic and Mission Reliability

Protective relays play a fundamental role in power systems, whose functions consist of three parts, namely protection, automation, and control, thus called the PAC altogether. It turns out that the architecture of a PACS (protection, automation, and control system) may exert a direct impact on the reliability of protective relay systems, previous studies of which are often conducted on the assumption that intelligent electronic devices (IEDs) have a constant fault rate with only mission reliability of the systems considered. To obtain a more accurate evaluation of system reliability bearing system maintenance in mind, this article proposes a novel method to appraise the reliability of PACSs with integrated consideration of basic and mission reliability. Firstly, the basic reliability of IEDs is calculated by parts count prediction, which will provide a more precise fault rate of IEDs. Secondly, the reliability of PACSs is analyzed by the reliability diagram and Markov model. By using the parts count prediction method to calculate the failure rate of the device, the steady-state probability rate will be accurate more than 0.0107%. At last, a quantitative criterion is finalized for selecting a suitable architecture easily.

Toward Wireless Smart Grid Communications: An Evaluation of Protocol Latencies in an Open-Source 5G Testbed

Fifth-generation networks promise wide availability of wireless communication with inherent security features. The 5G standards also outline access for different applications requiring low latency, machine-to-machine communication, or mobile broadband. These networks can be advantageous to numerous applications that require widespread and diverse communications. One such application is found in smart grids. Smart grid networks, and Operational Technology (OT) networks in general, utilize a variety of communication protocols for low-latency control, data monitoring, and reporting at every level. Transitioning these network communications from wired Wide Area Networks (WANs) to wireless communication through 5G can provide additional benefits to their security and network configurability. However, introducing these wireless capabilities may also result in a degradation of network latency. In this paper, we propose utilizing 5G for smart grid communications, and we evaluate the latency impacts of encapsulating GOOSE, Modbus, and DNP3 for transmission over a 5G network. The OpenAirInterface open-source library is utilized to deploy an in-lab 5G Core Network and gNB for testing with off-the-shelf User Equipment (UE). This creates an effective 5G test platform for experimenting with different OT protocols such as GOOSE. The results are validated by measuring two different Intelligent Electronic Devices’ contact closure times for each network configuration. These tests are also conducted for varying packet sizes in order to isolate different sources of network latency. Our study outlines the latency impact of communication over 5G for time-critical and non-critical applications regarding their transition toward private 5G-based OT network implementations. The conducted experiments illustrate that in the case of GOOSE packets, simple encapsulation may exceed the protocol’s time-critical nature, and, therefore, additional measures must be taken to ensure a viable transition of GOOSE to 5G services. However, non-critical applications are shown to be viable for migration to 5G.

Oriented BN/BNNT heterostructure constructed by interface engineering strategy for polyamide-imide composite film with advanced flexibility and thermally conductive properties

Thermal conductive polymeric materials have aroused increasing attention as thermal management materials in the field of intelligent electronic devices due to their intriguing advantages. However, the discontinuity of phonon transmission path construction represents the bottleneck for thermal conductivity enhancement of composite materials, which limits the practical application of composite materials. Herein, flexible polyamide-imide (PAI) thermally conductive composite films with hierarchical structure composed of synergistically assembled functionalized boron nitride nanosheets (FBN) and polydopamine (PDA)-modified boron nitride nanotubes (FBT) by layer-by-layer assembly strategy are constructed. Benefitting from the optimized interface engineering with the ordered oriented arrangement FBN/FBT filler structure, the obtained composite film with optimized hybrid filler contents exhibits the super high thermal conductivity of 71.1 W·m−1·K−1, prominent thermal conductivity enhancement as high as 3663 % and excellent mechanical flexibility. The introduction of FBT can further expand the thermal contact area attributed to its inherent high thermal conductivity and aspect ratio. Additionally, the consecutive dual-channel phono transmission paths can be constructed in PAI composites under the synergistic action of FBN and FBT, further improving the phonon transmission density and suppressing phonon scattering, which endows PAI composite films with excellent thermal conductivity under low load of filler. The resulting multifunctionalities make the PAI composite films promising for flexible intelligent wearable electronic devices as thermal management materials.

A Network Intrusion Detection System with Broadband WO3–x/WO3–x‐Ag/WO3–x Optoelectronic Memristor

AbstractReal‐time intrusion detection system based on the von Neumann architecture struggle to balance low power consumption and high computing speed. In this work, a strategy for network intrusion detection system based on the WO3–x/WO3–x‐Ag/WO3–x structured optoelectronic memristor overcoming the aforementioned issues is proposed and demonstrated. Through the modulation of electrical signals, the memristor successfully simulates a series of important synaptic functionalities including short‐term/long‐term synaptic plasticity. Meanwhile, when subjected to light stimulus, it demonstrates remarkable synaptic behaviors in terms of long/short‐term memory and “learning‐forgetting‐relearning.” Based on this memristor array, a convolutional neural network is constructed to recognize abnormal network records within the KDDCup‐99 dataset accurately and efficiently. The power consumption (10–6 W) is over seven orders of magnitude lower than that of central processing unit, etc. Subsequently, an intrusion detection system is established to integrate collection, processing, and detection of real‐time network data, successfully classifying various types of network records. Hence, this work is expected to promote the development of high‐density storage and neuromorphic computing technology, and provides an application idea for intelligent electronic devices.

Interoperability Challenges in Multivendor IEC 61850 Devices for Parallel Power Transformer Differential Protection

Interoperability of GOOSE messages is essential for the proper operation of protection schemes such as the parallel power transformer (PTRF) differential protection scheme, especially when using multivendor IEC 61850 devices. GOOSE messages allow for fast and reliable communication between intelligent electronic devices (IEDs) and are based on Ethernet communication. To ensure the interoperability of GOOSE messages between multivendor devices, adherence to the IEC 61850 standard specifications is crucial. The standard defines the format and content of GOOSE messages, including the data object model, data types, and communication protocols. Third-party testing and certification programs can also ensure compliance with the standard and help guarantee interoperability between different vendors. Device conformance with these standards does not ensure interoperability when devices from various manufacturers are utilized. Interoperability is necessary between the relevant devices from various vendors to provide system power stability and protection. If multivendor device interoperability is achieved, power utilities will be able to utilize multivendor devices in substations. The study investigates and provides comprehensive methods for achieving IEC 61850 standard-based interoperability problems in parallel with PTRF’s current differential protection schemes between IEDs (SEL-487E and MiCOM-P645) produced by different vendors under fault conditions. In a lab-scale environment with RTDS for real-time simulation in Hardware-in-the-Loop (HIL), the designed technique is simulated and tested.

A new triboelectric nanogenerator based on a multi-material stacking structure achieves efficient power conversion from discrete mechanical movement.

Due to its invaluable potential in discrete mechanical energy collection, TENG (triboelectric nanogenerator) is considered to satisfy the power requirements of intelligent electronic devices and drive the development of the Internet of Things (IoT). Nowadays, the promotion of TENGs has been hindered due to the limitation of their output performance and service life. Herein, a brand new triboelectric nanogenerator based on a multi-material stacking structure is proposed. By stacking various triboelectric materials in a specific order, a special charge balance state could be achieved inside the system such that the conductive layer generates more induced charges, and the output performance is significantly enhanced. Besides, due to the usage of the electropositive elastomer PU (polyurethane sponge), the design also effectively alleviates abrasion on the contact surface and adjusts its own output according to different compression environments. The experimental results show that the stacked PTFE/FKM/PU TENG (PFP-TENG) presents a more than 50% increase in transferred charge and almost 5 times the current output compared with the general contact-separation type TENG. When connected to the application circuit, the maximum output power reached 10.2 W m-2 and 145.2 W m-3, and more than 1400 LEDs could be easily lit. Finally, the PFP-TENG was also used to collect mechanical energy from simple motion and realize considerable power generation. This study not only provides new ideas for the design of TENGs by reasoning the theoretical model but also presents improved output performance, thus exemplifying the strong potential of this design in developing a power-generation device that can collect discrete mechanical energy.

Implementation of a Trust-Based Framework for Substation Defense in the Smart Grid

The Smart Grid is a cyber-integrated power grid that manages electricity generation, transmission, and distribution to consumers and central to its functioning is the substation. However, integrating cyber-infrastructure into the substation has increased its attack surface. Notably, sophisticated attacks such as the PipeDream APT exploit multiple device protocols, such as Modbus, DNP3, and IEC61850. The substation’s constraints pose challenges for implementing security measures such as encryption and intrusion detection systems. To address this, we propose a comprehensive trust-based framework aimed at enhancing substation security. The framework comprises a trust model, a risk posture model, and a trust transferability model. The trust model detects protocol-based attacks on Intelligent Electronic Devices and SCADA HMI systems, while the risk posture model dynamically assesses the substation’s risk posture. The trust transferability model evaluates the feasibility of transferring and integrating a device and its trust capabilities into a different substation. The practical substation emulation involves a Docker-based testbed, employing a multi-agent architecture with a real-time Security Operations Center-influenced dashboard. Assessment involves testing against attacks guided by the MITRE ICS ATT&amp;CK framework. Our framework displays resilience against diverse attacks, identifies malicious behavior, and rewards trustworthy devices.

Power System Fault Detection and Analysis Using Numerical Relay in Power grid Corporation Limited, Shoolagiri

The faults in a power system may be of various nature and they may affect the stability of the power system by causing outage of the line, there by overloading other connected lines and also causing cascading effect in the system. In order to access the nature of fault and analyze the impact of the same in a power system, fault analysis is required to be carried out as the same will be useful for the system operation and to take quick decisions in securing the system. In this paper we discuss the various types of faults in EHV system that may occur in line or substation. These faults are identified by Numerical relays which use IEDs [Intelligent Electronic Device]. The faults identified includes symmetrical and unsymmetrical faults in power system. Further in this project, we have taken into consideration the theoretical and practical study of the fault analysis through Numerical relays. In case of occurrence of Transient faults, Auto re-closure works with dead time of 1 sec. Current, voltage, Breaker status (open, close) are graphically represented by Disturbance Recorder. Events are recorded by Event logger. The above mentioned project for faults and analysis of faults in line or substation were carried out at Power grid Corporation Limited, 400 / 230kv Sub-Station Shoolagiri.

Automated fault location scheme for low voltage smart distribution systems

AbstractIntegrating the self‐healing capability realizes the automated protection of smart distribution systems. This article presents a fault location scheme for low voltage (LV) distribution systems based on the information collected from the smart meters. First, a fault condition is detected and classified by processing the current signal at the secondary side of the distribution transformer by an intelligent electronic device. Then, the faulty feeder and section are determined by calculating the fault‐imposed component of nodal voltages. The reliable performance of the proposed scheme is verified through several case studies using a real semi‐rural distribution system.

Fault Detection in a Single-Bus DC Microgrid Connected to EV/PV Systems and Hybrid Energy Storage Using the DMD-IF Method

Variations in fault currents, short times to clear the fault, and a lack of a natural current zero-crossing point are the most important challenges that DC microgrid protection faces. This challenge becomes more complicated with the presence of electric vehicles and energy storage systems due to their uncertainties. For this reason, in this paper, a new method for fault detection in DC microgrids with the presence of electric vehicles and energy storage systems is proposed. The new proposed method uses the combination of dynamic mode decomposition and instantaneous frequency for fault detection. In this method, first, a reference signal is made using the voltage and current signal sampled from the DC microgrid using the dynamic mode decomposition method. Next, in order to detect the fault, the instantaneous frequency value of the reference signal is calculated by the Hilbert transform. The simultaneous use of voltage and current signals reduces the transient effects of the control system on the proposed protection method. In order to measure voltage and current signals, only one intelligent electronic device unit is used in this paper. The proposed new method has been tested on a single-bus DC microgrid with the presence of electric vehicles and energy storage systems in MATLAB 2019b software. The results show that this method can detect all types of faults in DC microgrids, electric vehicles, and photovoltaics. Also, this method is immune to the uncertainties of the generation of distributed generation resources and the existence of noise distortions in the measured signals.