Vacuum circuit breaker is a kind of power equipment widely used in the power system. It is developing toward the direction of high voltage and high current. How to design the contact to maximize the interrupting capacity of the contact system has been conducted by scholars. In this paper, the magnetic field simulation model of contact system is established, the magnetic field distribution characteristics

Aiming at the constant current charging and the constant voltage charging mode of the power battery pack in an electric vehicle, this paper proposes a double‐sided LCL variable compensation topology in a magnetically coupled resonance wireless power transfer system. With the proposed topology, the complexity of the circuit design and control will be simplified. The mathematical model for the double‐sided

A thermal conductive plate in a device like a power module for an automobile requires materials with high thermal conductivity, acceptable electric breakdown strength, and high thermal stability. Thermoplastic polyimide (tpPI)/oriented hexagonal boron nitride (h‐BN) composite materials are produced by an electrostatic adsorption method. The tpPI/oriented h‐BN composite shows high thermal properties

Selection of current transformers (CTs) must be done carefully to ensure protection, control, and measuring systems function correctly. Some of the conventional CTs on medium voltage (MV) switchgear in nuclear power plants (NPPs) perform poorly due to accuracy errors and saturation. This paper suggests the use of electronic current transformers (ECTs) as a solution. Simulations were done on a 13.8

In recent years, with the large‐scale access of distributed generation (DG), the line voltage of the distribution network will be offset, which will adversely affect users. This paper aims at the voltage adjustment of the distribution network. Firstly, the reactive power control methods of distributed static synchronous compensator (DSTATCOM) and electric spring (ES) are studied separately, and then

Dissolved gas analysis is an important way to diagnose transformer faults. Compared with the method of establishing a single classifier based on artificial intelligence for diagnosis, ensemble learning (EL) can combine multiple classifiers to achieve stronger generalization ability and better diagnostic performance. But the traditional EL belongs to homogenous ensemble in which the base learners are

The perturbation and observation method (P&O method) is commonly used for maximum power point tracking in wind energy conversion systems. However, the selection of a suitable step size for this method is the key challenge when employing this technique. To address this, the paper presents a new method, called the FLC‐P&O method, in which a combination of fuzzy logic control (FLC) and the conventional

During the last few years, significant progress has been made in the theoretical understanding of deep networks. We review our contributions in the areas of approximation theory and optimization. We also introduce a new approach based on cross‐validation leave‐one‐out stability to estimate bounds on the expected error of overparametrized classifiers, such as deep networks. © 2020 Institute of Electrical

Time series forecasting is an important type of quantitative model used to predict future values given a series of past observations for which the generation process is unknown. Two of the most well‐known methods for the modeling of linear time series are the autoregressive integrated moving average (ARIMA) and the autoregressive fractionally integrated moving average (ARFIMA). For different datasets

We have developed a piezoelectric acoustic sensor that responds to rodents' audible frequency range as a front‐end device for a small hearing prosthesis system appropriate for animal experiments. The proposed piezoelectric transducer uses a biomimetic hearing mechanism that mimics bandpass‐filtering functions realized biologically in the cochlear membranes and hair cells of rodents via a frequency‐selective

For pulse train (PT) controlled switching converter operating in continuous conduction mode (CCM), a problem of low frequency oscillation is existed, which enlarges the output voltage ripple. In order to solve this issue, a constant on/off time pulse train (COOT‐PT) control technique with a buck converter is proposed, and the working principle is introduced in detail. Based on the variation of the

In both the research and engineering fields, missing data is a serious problem that cannot be overlooked. Therefore, available datasets with missing data are a challenge to be modeled by conventional global prediction models. In this paper, we propose a hybrid model consisting of an autoencoder and a gated linear network for solving the regression problem under missing value scenario. A sophisticated

The conventional artificial neural network (ANN) model is an effective way to detect harmonic signals. However, the solution of the model cannot converge when the initial value of the excitation function (IVEF) is not suitable, causing a large error in harmonic detection, especially in the case of power system noise. We improve the back propagation (BP) neural network (BNN) model by using an adjustable

Nondestructive and mass‐independent moisture content measurements are necessary for the quality control of wheat flours. Methods that use microwaves can evaluate the moisture content on both the surface layer and the inside of the bulk of the wheat flour. We describe the correlation between amplitude change at the resonance frequency and phase change at a specified frequency for varying masses of wheat

Theoretically, normally‐off silicon carbide (SiC) junction field‐effect transistors (JFETs) do not require a negative gate voltage supply because they are in an off‐state when the gate–source voltage is 0 V. However, most gate drivers for normally‐off SiC JFETs require not only a positive power supply for turning on the JFET but also a negative power supply for turning it off and maintaining a negative

Partial Discharge (PD) detection is an effective tool to diagnose the insulation condition of high voltage (HV) equipment. Among detection methods of PD, the ultra‐high frequency (UHF) method is distinguished by high sensitivity and safety operation. However, the UHF band includes many communication and broadcasting line spectral frequencies, which can be interference against the UHF method. From the

In recent years, several studies have been performed on methods of investigating the periphery of power lines using remote sensing. Among the survey methods using unmanned aerial vehicles (UAVs), those methods are being studied wherein the environment around power lines is photographed by a UAV, and separation measurements are performed by reconstructing the three‐dimensional (3D) point cloud between

A high‐voltage direct‐current circuit breaker is a key equipment to construct a flexible direct current transmission system. Most of the existing design schemes have some shortcomings such as slow fault‐breaking speed, poor current‐limiting effect, large capacity of the arrester, and long reclosing operation time. To solve the above problems, this paper proposes an H‐type high‐voltage direct current

When optimizing the design of electrical machines, it is recommended to take into account the effect of the manufacturing processes on the core losses and magnetic properties of the electrical steel. This paper demonstrates a methodology for incorporating the effects of interlocking, a process frequently applied to fix a stack of laminations, on the magnetic properties of the machine core. The methodology

In car‐bicycle collision simulations, it is often the case that conditions are set so that the direction of travel of the bicycle is orthogonal to that of the car. However, in actual traffic accidents, the position and posture of the bicycle at the time of the collision are not always constant. In this paper, we reproduced a two‐lane straight road with frequent traffic using a cycling simulator constructed

For a gas‐solid insulation system with direct current (DC) voltage, the surface charge accumulation and decay phenomenon are directly related to the capacitive‐resistive electric field transition process. The accumulated charges will affect the electrical insulation performance of a gas‐solid insulation system, which is a challenge for the development of DC gas‐insulated metal‐enclosed transmission

The key features of computer networks available for a disaster situation are reliable, fault tolerance, and self‐configurable. Therefore, using a wireless mesh network for disaster prevention and recovery system has gained much attention from the research community in the last decades. In addition, from the practical aspects of the network infrastructures of the disaster system, we should assume the

In recent years, human collaborative robots (HCRs) that work in the same space have attracted attention. HCRs with safety measures using a contact detection function are commercially sold. However, most safety measures for end effectors on HCRs are insufficient. In this paper, we propose a general‐purpose safety light curtain using Time of Flight (ToF) sensors for safety measure of an end effector

This paper presents a deep learning‐based face recognition device. It aims to instantly remind users of the identities of those who they met before in parties or conferences. When greeted, one, who is correctly identified, may frequently feel more respected than another who is mistaken for someone else in the first place. The golden rule suggests one to treat others with respect, and then others will

Magnetic stimulation is widely used as a medical treatment for neurological diseases. A reduction in the size of magnetic stimulation devices is desirable, however, because the coils are relatively large compared with electrode stimulation devices. Furthermore, in transcranial magnetic stimulation, the exact magnetically evoked areas in the brain and the mechanisms of neural activation are largely

Combining Schwarz–Christoffel transformation, magnetic field reconstruction method, and Maxwell stress tensor method, the calculation model of cogging torque of a dual‐stator axial flux permanent magnet machine is established. The end effect and slotting effect are both been taken into account. The results are verified by finite element method. And with the proposed method, calculation time can be

Methanol in transformer oil has been recently proposed as new marker of the aging of solid insulation in power transformers. Because the concentration of methanol in transformer oil is usually less than 500 µg/l and even less than 50 µg/l that cannot be detected by common methods. This paper combined static headspace sampling and solid‐phase extraction (SPE) as pretreatment, used SPE to adsorb and

Accurate fault classification is the premise of fault location and management study in a power distribution network. In most of the traditional fault classification methods used in power distribution network, the characteristic quantities are selected by experience, which will increase the uncertainty of fault classification results. A novel fault classification method based on deep belief networks

This paper proposes a hierarchical transient stability constrained optimal power flow (TSCOPF) analysis in a power system with a multi‐terminal voltage‐source converter (VSC) high‐voltage direct current (HVDC) system and large‐scale wind farms. This aims at determining the reinforcement and operation of the power system using the multi‐terminal VSC HVDC (MTDC) system. By the method, the wind farms

Recently, cameras with sensing technology have been used in vehicles to prevent traffic accidents. Although vehicle drivers can visually notice road signs, a recent study developed a recognition system for road signs to prevent traffic accidents. However, this system does not always perform the intended operation and encounters issues if the vehicle is driven at night, the road environment is bad,

The determination of blood glucose is usually performed in the laboratory or using invasive glucose meters. Unusual, fruity, or bad breath odor can be a sign of metabolic disease. The objective is the estimation of the blood glucose by breath analysis. To do that, we designed a three‐gas prediction model (alcohol, acetone, and propane). We exhaled in front of the three gas sensors and then recorded

The maximum correntropy criterion (MCC) algorithm has popularly been used in suppressing impulsive noise. It mainly relies on the choice of step size and kernel width. With the study of step size, this paper proposes a novel algorithm that updates the step size based on constructing a variable step size function that uses the moving weighted average algorithm to keep performance stable and sigmoid

Transistor aging occurs in nanoscale LSIs and is a factor that degrades large scale integration (LSI) performance. Because aging decreases the switching speed of transistors, LSIs ultimately malfunction due to the increase in the propagation delay. This paper proposes a procedure starting from the estimation of the aging amount at the metal‐oxide‐semiconductor field‐effect transistor (MOS FET) level

In order to solve the problem that the metro stray current cannot be directly numerically measured by the existing methods, and the data acquisition distortion caused by the special operating environment of the metro system, a new on‐line monitoring method for stray current was put forward in this paper. First, the stray current distribution function at different positions of metro trains was derived

In recent years, the design of new electronic equipment requires the development of new topologies for power supplies. The above is clear for portable equipment, which many times is classified as light loads. These new applications require power supplies with wide conversion ratios and better efficiencies. A solution to this problem is the use of two or more conventional converters connected in cascade

The metro stray current leaked during the subway operation causes the nearby earth surface potential to change, so that the various neutral‐grounded transformers to be at different earth surface potentials, resulting transformer DC bias. In order to analyze the influence of metro stray current on transformer DC bias, the polarization potential monitoring data in metro traction power supply system and

Grid‐connected voltage source inverters with LCL filters have been widely used for distributed generation systems in renewable energy systems. The presence of LCL resonance influences the overall performance and complicates the system control design, especially when the uncertainties caused by the component parameter variations and disturbances are considered. In order to improve the system performance

This paper presents a gain tuning method of the load torque compensator for direct speed control based on finite control set model predictive control (FCS‐MPC). In this method, the transfer function between the error in predicted speed and the load torque is constructed and used for gain parameter tuning of a load torque observer‐based prediction error correction. By using the proposed method, the

In today's fast‐paced environment, the downsizing of electronic devices has become imperative. A high driving frequency is effective for the downsizing of electronic equipment. However, one problem with high driving frequency is that it increases the ac resistance and heat generation on passive devices. Using a magnetic coating on the copper wire can effectively reduce the ac resistance. In this study

The coronary artery occlusion (CAO) acutely comes to human, and it highly threats the human's life. When CAO detected, percutaneous coronary intervention (PCI) should be conducted timely. Before PCI, localizing the CAO is needed firstly, because the heart is covered with various arteries. We handle the three kinds of CAO in this paper and our purpose is not only localization of CAO but also improving

This study was aimed at detecting flower areas in Convallaria keiskei colonies by using unmanned‐aerial‐vehicle (UAV) images. To estimate the number of Convallaria keiskei colonies, we focused on the effective features obtained from the information of flower color and location in the image obtained from the UAV. We proposed a method for estimating the number of colonies by combining image processing

Probabilistic solar irradiance forecasting has received widespread attention in recent years, as it provides more uncertainty information for the future photovoltaic generation. In this study, a hybrid probabilistic solar irradiance prediction method is proposed, which combines a deep recurrent neural network and residual modeling. Specifically, the long short‐term memory‐based point prediction using

Virtual synchronous generators composed of an inverter are affected by an over‐current caused by voltage dip and recovery. This letter addresses the current analysis under a symmetrical voltage dip and recovery. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

This study evaluates the optimal expansion of the electricity sector of the BBIN (Bangladesh, Bhutan, India, and Nepal) sub‐region with a detailed analysis of unevenly distributed resources and electricity demand, by developing a multi‐regional dynamic power sector optimization model, characterized by 27 nodes, 45 fuel transport lines, and 63 transmission lines in hourly temporal resolution. Scenarios

Safety‐related cables in nuclear power plants must be functional even during the occurrence of a severe accident. In this regard, flame‐retardant ethylene‐propylene‐diene rubber (FR‐EPR) widely used for electrical insulation in safety‐related cables was aged under several simulated severe accident conditions. Namely, 60Co gamma rays were irradiated at two different dose rates to sheets of FR‐EPR at

A headache and drowsiness are the most common symptoms of fatigue caused by a long duration of work using a visual display terminal (VDT). A sign of the headache generally involves placing a hand on the head, eyes, nose, or face. The recognition of these gestures is a challenging problem due to the difficulty in similar skin color of hands and face. In this paper, a method for classifying six hand

Assuming that the high‐gradient magnetic separation (HGMS) system based on a superconducting magnet can reduce iron oxide scale in boiler feedwater and contribute to the efficient operation of thermal power plants, we design a new matrix structure, which should efficiently capture iron oxide particles in boiler feedwater. We then evaluate their practicability experimentally and confirm that this HGMS

In this paper, considering a progressing trend of recent techniques for pitch detection of speech in noisy environments, windowing effects are discussed analytically, and it is insisted that the Rectangular window should be proactively used instead of the popular Hanning or Hamming window. In a variety of noise environments, a performance comparison of the conventional pitch detection methods is conducted

According to the latest grid‐connected standard, the failure of IIDG (inverter‐interfaced distributed generator), represented by wind power and photovoltaic power, is characterized by strong nonlinear output. Therefore, the protection scheme based on the traditional fault characteristics is difficult to be applied to the distribution network with high permeability IIDG access. Based on the low voltage

Evolutionary algorithm (EA) is a generic term for optimization algorithms inspired by biological optimization processes in the natural world. Although EAs are widely applied to complex real‐world problems because they do not require mathematical expression of target problems, theoretical design methods of EAs have not been established. To solve this issue, this paper proposes an approach of designing

Smart cities will be an important component for the construction of a sustainable future society. This paper focuses on the functionalities of smart cities from the perspective of electric power systems and reviews recent works on the various types of energy management systems (EMSs), particularly those focusing on the interaction among systems distributed in a city. Furthermore, this paper describes

Heavy‐duty vehicles have the advantages of heavy load, long transportation distance and so on, and ride comfort is an important feature of heavy‐duty vehicles. Flexibility of the heavy‐duty vehicle body is an essential factor in ride comfort, and a three‐axle heavy‐duty vehicle is the main commercial vehicle in China. To comprehensively analyze flexibility of vehicle body, elastic natural characteristics

A new type of DC electric field sensor has been developed. It is not mill type electric field sensor whose principle is to measure electric potentials in the atmosphere. The new type DC sensor can directly detect electric fields in all spaces. For minimizing disturbances of electric field configuration in the space, the new type sensor uses a simple linear dipole antenna. The key point in the detection

On the basis of existing studies presented in literature on optimizing permanent magnet (PM) shaping with third harmonic for the tile‐shaped magnetic poles under radial magnetization, this paper proposes a method for PM shape optimization using third harmonic for bread‐shaped magnetic pole under parallel magnetization. Furthermore, the optimal value of third harmonic that should be injected for achieving

As the increasing integration of inverter‐interfaced renewable energy generators intensifies the volatility and uncertainty of background harmonics in the utility system, it is crucial to construct a precise background harmonic model and determine the harmonic responsibility to promote harmonic management. This paper proposes a probabilistic model of background harmonics for harmonic responsibility

This paper presents the noninvasive determination of cardiac output by peripheral electrical bioimpedance. We validate our approach first with small animals and then with human. We established an experimental protocol that allowed us to perform the measurements of several cardiovascular parameters by two methods, echocardiography and bioimpedance. For the rats, we used a group of 19 Wistar rats. Peripheral

This paper describes the background of Electromagnetic Transients Program (EMTP) and reviews original EMTP development at Bonneville Power Administration of the US Department of Energy starting from 1966 to 1984. Then, the paper briefly explains the development and present situation of four EMTPs, that is, EMTP‐ATP, EMTP‐RV, EMTDC/PSCAD and XTAP. In addition, the line/cable parameters and the modeling

Reliability is an important performance for permanent magnet synchronous machine (PMSM) exploited to industrial applications and electric‐energy vehicles. Both air‐eccentricity and inter‐turn short circuit (ITSC) could induce the machine running in unbalanced status. Once not restored timely, the fault will lead to the whole drive system and its application damage. To enhance the reliability for PMSM

Aiming to the problem of large computation amount and high redundancy of traditional S‐transform methods available in the detection and classification of transient power quality disturbances, an efficient and accurate method for the detection and classification is proposed. First, the maximum power spectrum dynamics method is used to extract the main frequency points. Then, a called modified incomplete

Misalignment is a problem faced when electric vehicles work under the dynamic wireless charging mode using segmented transmitting coils. One kind of coil misalignment is coil lateral offset. In order to improve lateral offset tolerance, transfer efficiency and output power need to be stabilized. In this paper, first, the circuit model of a wireless power transfer (WPT) system is analyzed, from which