The contamination process of a model vacuum interrupter was investigated by measuring the amount of contamination and conducting direct simulation Monte Carlo (DSMC) evaluations. The numerical simulations revealed suitable results, and the simulation model could be used to predict the contamination profile. In addition, appropriate results for designing arc shields were obtained from a parametric study

The infrastructure construction of charging facilities for electric vehicles (EVs) is one of the key factors influencing the development of electric vehicle industry. A reasonable location and capacity determination scheme is very crucial to this issue. In this study, a probability calculation model that fully analyses the charging behavior of the owners is proposed to predict the charging load of

In this study, experiments pertaining to direct current (DC) interruptions are performed in an arc‐quenching chamber filled with silica sand. First, the arc column resistance is measured during DC arc‐quenching to demonstrate the elementary aspects of the arc in the silica‐sand‐filled space. Subsequently, an arrangement comprising a polymer cylinder between electrodes in the silica‐sand‐filled space

This paper proposes a predictive voltage control scheme baseda on short‐time‐ahead voltage fluctuation estimation in a distribution system for achieving high penetration of photovoltaic generation. In the proposed control scheme, the short‐time‐ahead voltage fluctuation is estimated from the previously measured voltage of the sensor, and the voltage regulator operates to minimize the expected voltage

Residual current circuit breakers (RCCBs) are used to provide electric shock protection, initial and periodical verification is necessary to check the effectiveness of RCCBs. This paper presents an auto‐monitoring system with simple application circuit and low power consumption, which can test the function of the current transformer, silicon controlled rectifier (SCR), tripping solenoid, controller

The spatial resolution of a cable fault location method by frequency domain reflectometry was examined experimentally by giving two abnormalities intentionally along a 31.5‐m coaxial cable. As a result, two clear signal peaks appear, which can locate the presence of two hot spots perfectly if they are separated by more than 30 cm at a position about 15 m from the cable end with a measuring device.

We introduce a novel approach for generating 2D RGB color images with a plot from the micro text (tweet) to be used for the overall polarity classification process of sentiment analysis. Researchers generally use word embedding and external resource‐based embedding techniques for text preprocessing of sentiment analysis through machine learning, neural networks, and natural language processing approaches

When lightning strikes a transmission tower or overhead line, the lightning current generates a spherically expanding electromagnetic field. The propagation mode of an expanding electromagnetic wave is different from that of a transverse electromagnetic (TEM) wave, which is applied to the modeling of transmission lines. This paper presents an equivalent circuit model of an overhead transmission line

DC‐link capacitor is one of the most vulnerable passive components in the drive system of electric vehicle, so the condition monitoring of DC‐link capacitors can significantly improve the reliability of drive system and even driving safety. The existing monitoring methods are subject to the low accuracy, added hardware and the irreversible impact on system. Therefore, based on Back Propagation (BP)

A simple thermal computation procedure of a metal oxide varistor (MOV) element, in which an impulse current is injected, is presented. The heat in the MOV, composed of many small cells, is computed with the discretized heat transport equation. At each time step, the injected impulse current is assumed to be distributed uniformly in the MOV. The power per cell is computed from the instantaneous values

A compressed arc extinguishing device for power distribution network is developed to solve the problem of existing anti‐lightning of power distribution network transmission lines. This paper first introduces the arc extinguishing principle of the arc extinguishing device, and then designs the lightning impulse voltage test around the 10 kV transmission line. The test results show that the U50% Lightning

Nanophotonic structures are artificial optical substances composed of structures smaller than incident light wavelengths. For example, it can artificially create a unique refractive index that is not found in substances in the natural world. That is, by designing the shape of the nanophotonic structure, an optical filter device that exhibits an optical response on demand can be realized. Also, we can

We analyzed a relationship between the viscosity and fine current of the ER suspension aiming for an estimation of the inner structure. This study aimed at an estimation of the inner structure formation via the fine current pass through the suspension. Viscosity and electrical current through electrodes were measured using similar apparatuses, and the relationship between the viscosity and fine current

Gas insulated metal enclosed switchgear (GIS) has been widely used in the world because of its compact structure and adaption to the environment. However, due to frequent operation and other reasons, GIS disconnector is prone to mechanical failure with poor contact, leading to abnormal vibration signals. In this paper, a GIS disconnector contact fault simulation platform is built to collect vibration

With increasing amounts of wind power generation installed, the steep fluctuation of wind power generation output, called ramp events, causes serious problems for power system operation. Controlling fluctuations is an important issue for increasing the amount of wind power generation as a wind farm (WF) in the future. The authors reported the scheduled operation method of WF using a battery energy

Significant benefits in economics and environment could be attained with the growing development of integrated energy system (IES). Energy hub (EH) has a large potential for realization the objective of implementing complementarity coordination and optimization of IES. EH is a device with multiple inputs and outputs, which plays a role of connecting hub in energy optimization, but it is difficult to

In this paper, according to the parameters of the dry type air core smoothing reactor, the stress‐sound field and fluid‐temperature field coupling simulation model is established, the detailed temperature field and sound field distribution are obtained, and the influence law of sound arrester on the sound pressure level and temperature rise are analyzed. It can be found that the temperature rise of

The ultra‐high frequency (UHF) method is attempted to diagnose the insulation condition of high voltage equipment as detecting partial discharge (PD) – emitted electromagnetic (EM) wave. Although the EM wave caused by PD has broadband, the UHF band includes many communication and broadcasting line spectral frequencies, which can affect PD detection as a noise. The authors have developed the multiple‐narrow

The communication network of wide‐area protection may be interrupted because of the severe environment or artificial damage. The delay of communication will increase so much that the wide‐area protection cannot work normally in some severe cases mentioned above. That is one of the factors which affect the application of wide‐area protection. A reconstruction algorithm including different circuitous

In recent years, intelligent structural damage diagnosis algorithms using machine learning have achieved much success. However, because of the fact that in real bridge applications, the working environment (load, temperature, and noise) is changing all the time, degradation of the performance of intelligent structural damage diagnosis methods is very serious. To address these problems, a novel bridge

A novel concatenated Lifting Wavelet Transform (LWT) and Walsh Hadamard Transform (WHT) with Universal Filtered Multi Carrier (UFMC) waveform is suggested as an alternative to Orthogonal Frequency Division Multiplexing (OFDM) waveform for the next generation wireless telecommunication systems in this paper. The suggested waveform is composed of LWT and WHT with UFMC waveform. Both the elimination the

Attributed graph is a typical class of graphs with a set of attributes on nodes, edges, even high‐order structure. Objects in the fields are naturally represented as attributed graphs with considerable noise and a large number of nodes, which make traditional graphs matching techniques confront with some new challenges, such as optimization difficulty, inability to match and so on. In order to solve

When targeting large spaces, temperature distribution occurs due to air flow. Therefore, when evaluating the some state quantity values in large spaces using the single‐mass model, the evaluation values cannot be accurately evaluated. In our developed method, we analyze in advance flow distribution with high computational load and make contributed ratio of indoor climate (CRI). By using CRI for making

Subspace‐based blind carrier frequency offset (CFO) estimation algorithms in orthogonal frequency division multiple access (OFDMA) systems have been developed in the literature. However, the algorithms have some restrictions or require high computational complexity. In this paper, we propose simple iteration schemes to reduce complexity with an adaptive manner and present a time‐variant CFO adaptive

Along with the progress of deep learning techniques, people tracking using video cameras became easy and accurate. However, privacy and security issues are not enough to be concerned with vision‐based monitoring. People may not be tolerated surveillance cameras installed everywhere in our daily life. A camera‐based system may not work robustly in unusual situations such as smoke, fogs, or darkness

An interleaved parallel high step‐up DC‐DC converter with cross‐coupled inductors for low current/voltage ripple and auto‐current sharing was proposed in this paper. This converter applies interleaved parallel input which decreases the input current ripple significantly. Due to the interleaved coupling effect of three coils of the cross‐coupled inductors, this converter can realize automatic current

In recent years, electric vehicles have developed rapidly. However, as the power source of electric vehicles, lithium battery has poor performance at low temperature, and has some problems such as reduced capacity and increased internal resistance. In this paper, two thermal environments, including natural convection condition and near‐adiabatic condition, are established, and discharge capacity test

Magnetic hyperthermia is very promising cancer therapy in which heating temperature is expected to be a key determinant for its success. Herein, we present a simple, real‐time, and high‐accuracy proportional‐integral‐derivative‐based temperature control system for magnetic hyperthermia using widely‐used induction heater and fiber optic thermometer. Our in vitro result shows that the temperature of

The voltage generated across a zinc‐oxide (ZnO) element, in which a lightning impulse current flows, has been computed with the finite‐difference time‐domain (FDTD) method. Also, the distribution of temperature in the ZnO element has been computed on the basis of FDTD‐computed conduction current densities with a discretized heat equation. The ZnO element having a thickness of 37 mm and a diameter of

We have developed a multipoint laser Doppler velocimeter (MLDV) that can measure blood flow velocity non‐invasively. The device can acquire blood flow velocity in absolute value and image the blood flow distribution. Absolute values of blood flow velocity indicated a follow‐up on the affected area. Therefore, we have performed a follow‐up for melanoma and breast cancer. However, this device does not

This study proposes a novel method for estimation of the acid value and the furfural contained in the insulating oil of an oil‐filled transformer based on the information received from the color of the insulating oil. A spectrometer analysis is carried out on insulating oils. The color data, represented as L*, a*, and b*, are measured, and it is found that these values change on a certain trajectory

Traditional modeling and optimization methods for high voltage equipment, specially, circuit breaker components and nozzles, require manual testing and improvement of a large number of parameters, and the efficiency is relatively low. The strong processing power of artificial intelligence technology in the identification and prediction of complex systems is an effective solution in such case. This

This study presents the effect of direct current (DC) electric field application on ice sterilization. The sample used was Escherichia coli (JM103) in a 0.001, 0.01, or 0.1 mol/L NaCl aqueous solution. The experimental sample was placed in a cuvette with parallel electrode plates (distance between electrodes: 1 mm) and then cooled at −30 °C or −80 °C for 40 min. After freezing, a 100 V DC voltage was

Gas‐insulated lines (GIL) are widely used due to their many advantages in power plants and substations. The security and reliability of GIL is achieved by continues testing and monitoring. The main fault in the GIL compartments is overheating, which is rarely to occur, nonetheless, it cannot be ignored. In the present study, GIL steady‐state thermal behavior was investigated. For this reason, a multiphysics

In order to solve the shortcomings of traditional orderly charging strategy, such as the inability to accurately respond to EV load, the difficulty to formulate an effective charging strategy and the lack of positive response from users. In this paper, a novel interactive network model of distribution network and electric vehicles is constructed. The optimization factor is assigned to the charging

Aiming at the problem of unnecessary waste of power resources in the power system caused by the uncertainty of wind farm output, and then affecting the economics of the system. This paper proposes a power system scheduling model based on wind power output forecasting errors. In the forecasting stage, in view of the defect that the Fruit Fly Optimization Algorithm (FOA) is easy to fall into the local

In this paper, a fluid‐thermal coupled finite element model is established based on the design parameters of dry‐type core reactor, the detailed temperature distribution results are given, and the heat transfer process of the layer coils was analyzed. Meanwhile, the electromagnetic characteristics of core reactor have been analyzed, it shows that the structure parameters adjustment of layer coils have

This study investigated mechanical faults in oil‐immersed power transformers with disc‐type windings. Short‐circuit tests were conducted on eight aged removed transformers. Before the short‐circuit tests, accelerated aging tests were conducted on all the transformers to discuss the life limit of transformers. Six out of eight transformers experienced the internal ground faults. Although the radial

The problem of shafting torsional vibrations has been increasingly emerging due to the increasing capacity of turbo‐generator and the complexity of power grid. Therefore, how to reduce the torsional vibration of the turbo‐generator shaft and improve the stability of the power system has become the focus of our research. First, in order to solve the problem and alleviate the torsional vibrations of

Since the large‐scale protein sequence data is available, applying deep neural networks to mine better features from the sequences becomes possible. Eukaryotic protein subcellular localization prediction which makes a contribution in many biology process, has used protein sequences in many automatic predicting methods. Moreover, gene ontology (GO) annotation has been shown to be helpful in improving

Facial expression is one of the most direct and effective ways to recognize emotions, widely used in human‐computer interaction, affective computing, and other research fields. Expression recognition can be divided into discrete expression classification and continuous dimensional emotion recognition. Most of the existing multi‐dimensional emotional estimation only considers the data under laboratory

A novel single antenna interference cancellation algorithm of frequency shift keying (FSK) signal based on virtual multi‐input multi‐output (MIMO) is proposed in this paper. The idea is to form a virtual MIMO detection model from one‐dimensional signal through over‐sampling, then the pseudo‐Inverse matrix of transfer matrix can be used to complete demodulation. Simulation results are presented to indicate

This paper reports analytical evaluation for minimum reverse recovery loss and turn‐off loss of PiN diodes and IGBTs, respectively. In this evaluation, we take account of structural parameters and current continuity at the both ends of the i‐layer, and we calculate switching losses (E) from energy dissipation on the i‐layer during switching action by using position integration instead of time integration

The effects of extremely low‐frequency (ELF) electric field (EF) exposure on brain activity remain poorly understood. This study sought to examine the acute effects of EF exposure on brain activity by analyzing electroencephalogram (EEG) basic rhythms. The heart rate variability (HRV) was also measured to evaluate autonomic activity. Using a system that enables measurement under EF exposure, occipital

The recent literature indicates that face recognition and facial expression classification has achieved a high accuracy on benchmark datasets with a large number of face images in the wild. On the other hand, unlike the purpose of recognizing as many people as possible, real applications for families or companies usually aim to recognize a small group of people as accurate as possible. In case of the

Owing to a lack of systematic mathematical models to represent the parameters related to micro‐source disconnection, the stability of interaction between a grid and a micro‐grid with series micro‐source inverters (SMSI‐MG) is difficult to analyze. In this study, the average ratio and the degree of imbalance of three‐phase micro‐source disconnection, denoted respectively by δ and ϵ, are defined, and

To maximize the velocity and energy conversion efficiency of the synchronous induction coil launcher, the pre‐analysis of the armature interception effect(AIE) is conducted, and the dynamic mathematical model of the single‐stage coil launcher is established theoretically. According to the mathematical model and analysis, the AIE is an intrinsic characteristic of the synchronous induction coil launcher

Electromagnetic coil launcher is a kind of special linear motor. In order to study the trigger principles of multi‐stage electromagnetic coil launcher, based on the electromagnetic field theory, the paper deduced the field‐circuit coupling magnetic field control equations of multi‐stage synchronous inductive coil with the consideration of inter‐stage coupling, and analyzed the distribution law of magnetic

Differential evolution algorithms have become one of the most competitive evolutionary algorithms, among which a chaotic differential evolution (CJADE) is a recently proposed state‐of‐the‐art variant. But CJADE still suffers from the premature convergence problem. This paper further improves CJADE by innovatively incorporating a success‐intensity‐based roulette wheel selection method into it. The resultant

This paper presents a deep neural network‐based technique to recognize pets' body movements. The motivation to develop the technique arises from the fact that there are an increasing number of animal lovers, say dog or cat lovers, who spend a tremendous amount of effort to take care of their beloved pets, and even to capture the pets' images in daily life and at particular memorable moments for sharing

The flow state is an ideal state of work performance. A previous study concluded that the flow state might, in fact, be accompanied by increased parasympathetic modulation of sympathetic activity. However, there is little knowledge about the relationship between the flow state and thermal physiological indices. Nasal skin temperature is a remotely measurable index of autonomic nervous system activity

The air‐cathode is investigated for the development and optimization of low‐cost, miniaturized, portable, quasi‐solid aluminum‐air batteries. The battery used aluminum as the anode and gelation sodium chloride as the electrolyte. The air‐cathode was activated carbon sheet made of carbon fiber, cellulose, and activated carbon powder. The air‐cathode requires a large surface area. Activated carbon (AC)

Correction to the article TEE23147 published in the July issue of IEEJ Transactions on Electrical and Electronic Engineering, Vol. 15, No. 7, 2020, pp. 1032–1039. DOI:10.1002/tee.23147 Equation 9 of the above article was published incorrectly as: (9) It should read as follows: (9) The author apologizes for the error and any inconvenience it may have caused.

Model predictive control has been wildly used in the modern power electronic converter with the advantages of the multi‐objective optimization, no additional modulator is required and small grid current harmonic. However, the switching operation is not constant and higher sampling frequency must be required. A novel direct power control using model predictive control (DPC‐MPC) strategy is presented

Most of home appliances were put into practical use in the United Kingdom and the United States before early 20th century. However, in Japan, the production of the home appliances began in the 1950s. Home and consumer appliances market had been expanded and developed growing with high growth of Japan in 1950–1970. They are applied by power electronics for improvement of performance and energy saving

Under strong wind caused by a low pressure with fronts passing near Honshu, I have observed weather clutter containing targets (ships) using an X‐band marine radar with a frequency of 9.41 GHz, a beamwidth of 1.0°, a pulsewidth of 0.5 μs, and a pulse‐repetition frequency of 1600 Hz. To investigate such clutter amplitude statistics, I have introduced the Nakagami‐m distribution to radar signal processing

The purpose of this paper is to deeply study the actual contact state of sealed relay contact surface, restore the contact spots of contact pair, and make up for the deficiency of establishing contact model of contact pair only by theoretical simulation. In this paper, the electrical contact high‐speed camera system is selected to record the kinematic parameters during the pull‐in process of the contact

The electron temperature and the density of argon arc plasma plume injected into water were observed through optical emission spectroscopic measurement. Argon arc plasma jets were generated with a DC arc current of 40–200 A by a non‐transferred arc discharge plasma torch under atmospheric pressure, and ejected through a nozzle on the anode into water or gas‐phase argon. The electron temperature of

To study the effectiveness of infrared and UV imaging technology to detect zero‐value insulators, the infrared thermal images and UV videos of zero‐value insulators at different positions on insulator strings were collected at different humidities and levels of pollution. The heat and discharge characteristics of the insulator strings were analyzed. The thermal‐electric multi‐physics simulation models

Increasing effort of solar power integration to the grid could be accelerated towards sustainability goal. However, high PV penetration ratio (PVR) in turn critically reduces system frequency response performance of an existing power system due to reduction of on‐line rotating generators. Besides intrinsic system inertia, system RC plays a vital role in dynamically securing the power system operation