样式: 排序: IF: - GO 导出 标记为已读
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An experimental study on fire ignition in collector cable in wind power generation system caused by direct lightning strike Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-23 Ken-ichi Seki, Takashi Tsuchida, Atsushi Akiba, Hiroyuki Tada, Shozo Sekioka
A separable connector is used for the power cables and apparatuses in renewable energy systems. The shield of the collector cable is sometimes an open circuit at one end to reduce power loss due to the shield current. However, this has a disadvantage from the viewpoint of lightning protection. The semiconductive part of the separable connector is grounded for safety. The ground potential rise due to
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Analysis of high-frequency electromagnetic ringing phenomenon under GaN-FET inverter excitation Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-20 Norihiro Ogishima, Nguyen Gia Minh Thao, Keisuke Fujisaki
In this study, the ringing phenomenon of gallium nitride-field effect transistor (GaN-FET) and silicon-insulated gate bipolar transistor (Si-IGBT) inverter excitations in a ring sample was thoroughly measured and analyzed by using a high-quality oscilloscope with a very high sampling rate of 5 giga-samples per second (GS/s). Owing to the rapid switching of the GaN-FET power devices in several nanoseconds
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Filament analysis based on mathematical morphology of surface dielectric barrier discharges in N2/O2 mixtures Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-14 Takuma Uemura, Atsushi Komuro, Ryo Ono
In this paper, we measured the electrical potential distribution of surface dielectric barrier discharges (SDBD) caused by alternating voltage in synthetic air and nitrogen using the Pockels effect. It was shown that different potential distributions of filament thickness and length are generated in synthetic air and nitrogen. A filament analysis based on mathematical morphology was performed to quantify
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Circuit equation in power superimposition for position sensor using single-phase transformer on PMSM power lines Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-15 Takeshi Kiribuchi, Yukinori Inoue, Shigeo Morimoto
Permanent magnet synchronous motors (PMSM) are very popular in the industrial market. Recently, robots are installed to compensate for the shortage of labor. Due to the increase in motors, the number of power lines and position sensor cable wiring are increased; this increase in complicated wiring is a problem. As a method to solve these problems, power superimposition technology in the power line
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Fault current limiter principle by switching magnetic circuit Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-14 Mitsuru Tsukima, Yamato Hatauchi
Several types of fault current limiters have been studied so far, including superconductor based one or nonsuperconductor based one. However, it is difficult to satisfy all requirements for cost, maintainability, and current limiting performance. This study proposes another type of fault current limiter, variable transformer based one. It is supposed to be less expensive and easier to be maintained
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Atmospheric pressure argon plasma jets I – Measurements of spatial distribution for visible emission spectrum and vacuum ultraviolet Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-14 Susumu Suzuki, Kenji Teranishi, Haruo Itoh
This paper describes the observed position dependent emission spectrum and vacuum ultraviolet (VUV) to clarify the optical structure of argon atmospheric pressure plasma jets (APJs). Visible emission spectra of argon, nitrogen, and OH molecules were measured as a function of position from the nozzle of plasma jet generator to gas flow direction. From the results, we realized that a certain electric
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Development of event-based centralized excitation control method of synchronous generators for improving the transient stability Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-14 Fumichika Yamaoka, Kenichi Kawabe
Maintenance of transient stability is important for the stable operation of power systems. However, as a large amount of renewable energy sources are concerned that the transient stability deteriorates. Excitation control systems have been widely used to improve the transient stability. The defect is that only the synchronous generator (SG) near the fault location changes the excitation voltage so
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Experimental verification of voltage boost control in a hybrid system using D-EPC Electr. Eng. Jpn. (IF 0.4) Pub Date : 2024-02-12 Hiroki Matsuno, Hiromu Akiyama, Kantaro Yoshimoto, Tomoki Yokoyama
A novel voltage boost system using DC-inputs direct electric-power converter (D-EPC) is proposed. D-EPC is an inverter that can control the distribution of power from two sources. In this study, a voltage boost system without boost chopper was developed using the power distribution control of D-EPC. The power distribution control can control the voltage of the smoothing capacitor in the D-EPC. The
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A circuit model of electrical wiring nearby building structure for lightning surge analysis Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-12-04 Hideyuki Dei, Yoki Ikeda, Naoto Nagaoka
A model expressing beams, pillars, and electrical wiring in a building for lightning surge simulation by circuit analysis method is proposed in this paper. The proposed model expresses the self-surge impedance of the electrical wiring as a function of the distance between conductors and the radius of the electrical wiring. The mutual impedance is expressed by the distance between the surfaces of a
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Transformer-less drive and operation stability analysis of dielectric barrier discharge using a double resonance circuit Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-12-04 Taichiro Tamida, Ryota Nagata, Taiga Itani
A dielectric barrier discharge load (DBD) with a maintenance voltage of 1.5 kV has been successfully driven stably from a 48 V inverter only by resonance voltage boost and no transformer. The proposed circuit consists of a two-stage resonant circuit. The circuit operation is investigated using both prototyping measurement and circuit simulation, which shows that despite the high Q value, the design
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Analysis of interference of electromagnetic noise in an electric compressor for vehicle air-conditioning systems with an integrated mechanical and electrical structure Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-11-28 Iori Uda, Satoshi Ogasawara, Koji Orikawa, Koji Kobayashi, Hiroshi Yoshida, Tatsuki Kashihara, Kohei Takada
Since a motor drive system contains an inverter (high-voltage circuit) and gate drive circuits (low-voltage circit) with a switching regulator, electromagnetic noise is generated in each of these two circuits, and noise interference between these circuits can occur. This paper discusses noise interference between the high- and low-voltage circuits of an electric compressor system with an integrated
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Power factor control for inverters under high penetration of distributed generation Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-10-17 Yasuaki Yamada, Toshiya Nanahara, Kazuto Yukita
The paper proposes a method to select a power factor for an inverter of distributed power generation systems to keep appropriate voltage of a power system with the high penetration of inverter-interfaced generation. The increase of inverter-interfaced power sources, such as wind and photovoltaic power generation, arouses concerns on the voltage fluctuations in a power system. While constant power factor
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Function and role of bus bar protection relay in distribution substation Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-10-03 Yuki Matsuda, Takayuki Inui
Bus bar of substations are important equipment where multiple facilities are centrally connected, and the impact of a fault is significant. Therefore, bus bar protection relays have unique functions to correctly detect the point of fault, which allows high speed fault elimination and minimization of outage area. This paper describes functions and roles of bus bar protection relays applied in distribution
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Optimization of train timetables and placement of charging facilities for battery-powered LRT Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-10-02 Kosuke Horiuchi, Masafumi Miyatake
The energy consumption of a battery-powered train in an interstation depends on the running time and state of energy (SOE) at departure. In this paper, we develop an optimization method of train timetables to minimize energy consumption in line with several stations. The variables in this proposed optimization model are running, dwell, and charging times as real numbers and places of charging facilities
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Fundamental experiment and numerical simulation of pre-ionized inert gas plasma MHD electrical power generation Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-09-27 Ork Kimsor, Yoshinobu Kodera, Yoshihiro Okuno
The experiments of pre-ionized inert gas plasma MHD electrical power generation are conducted, and the performance and plasma behavior in the experimental generator are examined through time-dependent r-_ two-dimensional numerical simulation. In the experiment, an enthalpy extraction ratio of 4.01% has been obtained with a disk-shaped MHD generator with radio-frequency pre-ionization. In the numerical
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Development of a three-phase power-flow calculation method for distribution systems with automatic handling of arbitrary winding connections of transformers Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-09-23 Guilherme Cirilo Leandro, Taku Noda
Single-phase loads and photovoltaic generation cause three-phase imbalance in distribution systems, and prospective growth of normal chargers of electric vehicles may even increase the imbalance. The analysis of such unbalanced systems requires the three-phase power-flow calculation. Since existing methods require the admittance matrices of three-phase transformers, they must be derived for all possible
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End effects of Halbach field magnet-type linear motor Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-09-08 Hiroto Yamaguchi, Mimpei Morishita
A linear motor that uses a finite length Halbach array as its magnetic field causes a thrust force ripple owing to end effects. In this paper, the theoretical and numerical analysis methods of the Halbach array are investigated. The results of the electromagnetic field analysis are compared to confirm the validity of the theoretical and numerical solutions. Moreover, we focus on the magnetic pole period
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Evaluation of vector magnetic property in a three-phase induction motor model core with visualization of streamline Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-09-07 Yuichiro Kai, Ryoya Maeda, Masato Enokizono
In this paper, a streamline display method for magnetic flux density and magnetic field strength vectors in a three-phase induction motor model core is presented, and the relationship between streamlines and magnetic properties is investigated. It is possible to visualize the vector magnetic properties distribution by representing the magnetic flux density and the magnetic field strength vector with
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Measurements of electrical resistances and investigations of factors affecting corrosion and breakages of shielding layers in extruded three-layer 6.6 kV XLPE cables Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-09-03 Takashi Kurihara, Kenichi Kimura, Takuya Watanabe, Tomoyuki Sato
Corrosion and breakages of shielding layers are one of the factors for degradation of extruded three-layer (E-E type) 6.6 kV cross-linked polyethylene (XLPE) cables. Tohoku Electric Power Network has been measuring electrical resistances of shielding layers in E-E type 6.6 kV XLPE cables, and recently has found breakages of shielding layers. The authors performed an accelerated degradation test for
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Optimizing service restoration in distribution systems based on scheduling of crews considering priorities of loads Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-08-25 Shinya Sekizaki, Teruyuki Kato, Ichiro Nishizaki, Tomohiro Hayashida, Kazuhisa Hikoyama, Tomoaki Nonoyama
The service restoration to sound sections within a short period as much as possible, performed after the permanent fault occurs in a distribution system, is significant for maintaining power supply reliability. This paper proposes an efficient method to find service restoration procedures based on fault searching and the optimal work scheduling of crews, considering the power supply priorities of loads
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Semiconductor piezoresistance prediction model for mechanical sensor design Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-08-19 Ryo Nakanishi, Ryo Morikawa, Masashi Kawai, Takumi Nakahara, Toshiyuki Toriyama
This paper addresses semiconductor piezoresistive materials selection in MEMS engineering design. From the practical engineering point of view, it is important to understand piezoresistance properties of semiconductors even if less accuracy under feasibility design phase. However, piezoresistance is frequently analyzed based on first principle electronic band structure simulations by sophisticate physicists
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Fundamental evaluation of direct-cooling technology for in-wheel drive system Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-08-18 Tetsuya Suto, Makoto Ito, Akeshi Takahashi, Ryuichiro Iwano, Takafumi Hara
We are developing a small and lightweight direct-drive system toward the realization of in-wheel electric vehicles (EVs). To increase the power density of the motor, we developed a direct-cooling motor that immersed the core, coils, and magnets in cooling oil and improved cooling efficiency. Moreover, we performed measurements of frictional loss, measurement of pressure drop, and a continuous heat-run
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Experimental and theoretical analyses on power generation characteristics of co-axial MHD energy conversion device Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-08-16 Takahiro Hasebe, Ryo Sasaki, Takayasu Fujino, Hidemasa Takana, Hiromichi Kobayashi
Experiments on power generation were conducted under the open-circuit condition to validate theoretical analyses on the power generation characteristics of a co-axial MHD energy conversion device. Considering distribution of externally applied magnetic field and the electromotive force induced by the rotation of the conductive inner cylinder, the results show that the experimental open-circuit voltage
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Electrical treeing phenomena in two-layer silicone gel with different crosslinking degrees and its dielectric strength Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-07-08 Risa Kuroda, Hyeon-Gu Jeon, Haruo Ihori
Silicone gel is widely used to encapsulate power modules, and improvement of its dielectric strength has been required. So, the purpose of our research is to improve dielectric strength of silicone gel encapsulant, and we focus on crosslinking degree of silicone gel. Previous studies have shown that growth mechanism of electrical tree changes with crosslinking degree of silicone gel. This suggests
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Formulation and mixing conditions of magnetic composite materials used for magnetic wedges in an interior permanent magnet synchronous motor Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-30 Manabu Horiuchi, Ryo Yoshida, Masami Nirei, Mitsuhide Sato, Tsutomu Mizuno
An interior permanent magnet synchronous motor (IPMSM) is characterized by its high efficiency. However, torque ripple and loss occur because of the spatial harmonics generated by air-gap permeance fluctuations. This study clarified that slot harmonic components can be suppressed by inserting magnetic wedges made of magnetic composite material in the slot opening of an IPMSM. First, the authors examined
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The high-frequency phenomenon of copper clad aluminum wires which are lower the alternating current resistance than copper solid wires, and the application of copper clad aluminum wires to the electrical equipment Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-22 Katsuhiko Ueda, Chefen Hung
The paper is proposed approximate formulas of the ac resistance of lead wires and coils which made by using copper clad aluminum (CCA) wires. There are the frequency range that the ac resistance of CCA wires is lower than it of cupper solid wires for lead wires and coils of an electrical equipment. It is shown that the application of CCA wires is economical as comparing with copper solid wires, if
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Area day-ahead photovoltaic power prediction by just-in-time modeling with meso-scale ensemble prediction system Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-13 Yusuke Mori, Shinji Wakao, Hideaki Ohtake, Takahiro Takamatsu, Takashi Oozeki
Photovoltaics (PV) output prediction, which is indispensable for power system operation, can affects demand and supply adjustment adversely when large prediction error occurs. Thus, the reduction of large error as well as average error is required in PV power prediction. In 2019, the operation of the Meso-scale Ensemble Prediction System (MEPS) of numerical weather prediction started from the JapanMeteorological
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Development of a short-term solar irradiance forecasting using satellite image in combination with numerical weather prediction model Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-12 Atsushi Hashimoto, Katsuhisa Yoshimoto
A short-term solar irradiance forecasting method has been developed to provide highly accurate prediction, using satellite image prediction model in combination with numerical weather prediction model. This method was applied and evaluated using the solar irradiance observational site at the CRIEPI Akagi Testing Center (Gunma Prefecture, Japan). Based on historical forecasting and observation datasets
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A novel method applicable to large-scale active magnetic shielding system which effectively compensates gradient magnetic fields originated from the surrounding buildings Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-10 Takuto Ogata, Naofumi Murata, Takafumi Shimizu
We propose the novel magnetic compensation method which is suitable to compensate gradient magnetic fields. The method is to be applied to a conventional large-scale, tri-axial active magnetic shielding system such as a spacecraft magnetic testing facility. The essences of this method are the adoption of compensation coils which have degrees of freedom in their coil orientations, and their installation
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Development of capacitive-coupled hall-type MHD generator Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-09 Gaigo Kato, Kazumasa Takahashi, Takashi Kikuchi, Toru Sasaki
We have demonstrated a capacitively coupled Hall-type MHD generator using ECR plasma. To clarify the characteristics of the fabricated MHD generator, we measured the power generation characteristics as a function of magnetic field strength using a DC Hall-type MHD power generation experiment. The results showed that the output power decreased due to magnetic pressure at the higher magnetic field. However
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MHz-driven snubberless zero-current soft-switching high step-up DC-DC converter with a multi-resonant tank Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-07 Tomokazu Mishima, Ryusei Miyazaki, Ching-Ming Lai
A novel high step-up DC-DC converter suitable for the power interface of fuel cells (FC) is presented in this paper. The proposed converter features a multi-resonant tank for achieving high-step up ratio under zero current soft switching (ZCS) without any snubber circuits. The simple and minimized-component topology is beneficial for megahertz driving of gallium nitride (GaN) power transistors with
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Design of a linearization model for three-phase PWM rectifiers for electrochemical machining Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-06 Atsushi Nakata, Akihiro Goto, Suguru Mototani, Akihiro Torii
Electrochemical machining (ECM) is a processing method for metals that uses a DC power supply and flowing electrolyte. In some cases, discharge occurs during ECM when the gap between the electrode and workpiece, whose distance is rather small, is filled with hydrogen generated via electrolysis. We attempt to utilize a DC inductor placed between the DC supply and the ECM load in order to limit di/dt
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Spatio-temporal distributions of accumulated charge density in atmospheric pressure dielectric barrier discharges Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-06 Haruaki Akashi, Tomokazu Yoshinaga
The effect of the secondary electron emission coefficient on accumulated charge density distributions in atmospheric pressure dielectric barrier discharges have been simulated using two-dimensional fluid model. Spatio-temporal distributions of accumulated charge density on each side of the dielectric have been examined. The differences of conventional waveforms of accumulated charge density and the
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Development of self-conducting current bypass circuit for series-connected diodes in high power semiconductor light source Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-06 Hiroyasu Iwabuki, Taichiro Tamida, Akihiko Iwata, Shigeo Morimoto
This paper proposes a self-conducting current bypass circuit for series-connected diodes in high power semiconductor light source. This circuit enables the main circuit current flow continuously, even if several of the diodes connected in series are open because of breakdowns. Herein, the composition, operation, and circuit design method of the proposed circuit are described. Moreover, the development
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Purely resistive load estimation for three-phase inverter by using pseudo random binary sequence signal Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-05 Masataka Minami, Naoya Morinaka
In recent years, the introduction of photovoltaic power generation systems has been increasing from the perspective of global warming countermeasures. However, there is a problem that it becomes difficult to adjust the supply and demand balance of electric power. Therefore, in this research, the inverter by using estimation signal estimates the load of the consumer, then we aim to adjust the supply-demand
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Fast short-circuit protection under current imbalance condition for multi-paralleled SiC-MOSFETs Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-05 Hiroshi Suzuki, Tsuyoshi Funaki
This paper proposes methodology and gate drive circuit that can immediately detect short-circuit (SC) of multiparalleled SiC-MOSFETs even under current imbalance condition. Proposed method detects SC current using an integration circuit that can sense di/dt. The detection level of SC current can be adjusted to a desired value regardless of the number of SiC-MOSFETs connected in parallel. The effectiveness
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Basic study on calibration using waveform variation in space charge measurement by pulsed electroacoustic method Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-05 Xiaoxin Li, Tomohiro Kawashima, Yoshinobu Murakami, Naohiro Hozumi
The pulsed electroacoustic method determines the distribution of space charge in an insulation system by applying a pulse voltage and detecting the acoustic response. It estimates the location and magnitude of charges from time-domain signals. For quantitative analysis, a bias voltage is applied to a specimen with no space charge, and the acoustic signal generated from the electrodes only is used as
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Common mode conductive noise cancellation for multiphase converter using auxiliary winding Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-06-03 Mamoru Sasaki, Jun Imaoka, Masayoshi Yamamoto, Akira Nakano, Koji Fuse
A multiphase DC-DC converter consisting of a coupled inductor and fast switching devices enables power electronics equipment to achieve a high-power density. However, with such devices, the fast voltage transition generates substantial common mode (CM) noise. However, there are very few studies on CM noise reduction for multiphase converters using a coupled inductor. Therefore, in this paper, a CM
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Development of fault cause estimation method for distribution line Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-26 Yoshikazu Iida, Masato Hirai, Masato Shiga, Tetsushi Ono, Tatsuki Inuzuka
We are planning to develop the new Advanced Distribution Automation System (ADAS) equipped with optical communication network and sectionalizer with sensor for more grid reliability and efficiency on maintenance operation. The new system is featured with the function of fault cause or damaged part estimation. The new sectionalizer captures the waveform of electrical line surge originated by fault and
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Development of energy saving operation technology for punctuality and ride comfort by optimizing the point of target pattern recreation Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-16 Yuhi Tsutsumi, Atsushi Oda, Keiji Maekawa
At present, there is a growing demand for energy saving to prevent global warming. Thus, the railway industry is also focusing on energy saving methods. Power consumption of running trains has a large variation of approximately 20% caused by drivers’ operation. Therefore, improving the running profile can considerably reduce energy consumption. Numerous algorithms for generating energy saving running
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A study on improving shielding performance of shielded cable Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-14 Takashi Tsuchida
With the developments in power electronics equipment, the electromagnetic environment has become severe for electronic equipment. In the smart facility field, the stable operation of electronic devices is indispensable, and noise countermeasures must be improved. To suppress intrusive noise from cables, shielded cables are used in many cases. However, electromagnetic induction cannot be suppressed
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Fundamental study for assessment of surface resistivity based on waveform characteristics of partial discharge Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-08 Tomohiro Kawashima, Taisuke Hirukawa, Kanta Yoshikawa, Yoshinobu Murakami, Naohiro Hozumi
The partial discharge (PD) waveform reflects the evolution process of electron avalanche in the discharge space. The authors expect to estimate the condition of the discharge space based on the PD waveform characteristics. The semi-conductive sheet was attached to the insulator to simulate the decrease in surface resistance due to deterioration. With the reduction of the surface resistivity, the shoulder
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Real-time supply-demand schedule update and operation for generators and battery energy storage system based on forecasted and actual photovoltaic power outputs Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-08 Taisei Yoshioka, Koji Nishio, Kohei Takahashi, Taisuke Masuta, Rajitha Udawalpola, Hideaki Ohtake
The photovoltaic (PV) power output might be frequently curtailed to maintain electricity supply-demand balance in future power systems. In our previous study, we proposed a new method for updating the battery energy storage system (BESS) charge/discharge and the generator unit commitment (UC) schedules based on the forecasted and actual PV power outputs. The forecast dataset was updated every 3 h (eight
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Scheduling method for aggregated photovoltaic-battery systems considering information notified by distribution system operator Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-07 Fumiya Hyodo, Yuki Sato, Taisuke Masuta, Thavatchai Tayjasanant
In recent years, the aggregation business has gained a lot of attention in Japan. Aggregators will make contracts with customers with photovoltaic (PV) power systems and battery energy storage systems (BESSs) including electric vehicles (EVs) to participate in electricity markets. Aggregators might have to pay electricity supply-demand imbalance charges when generated and consumed energies contracted
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Effects of a small amount of H2O on negative ion mobility and ion-molecule reactions in O2 at atmospheric pressure Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-07 Yui Okuyama, Yuka Yasuzawa, Hirotake Sugawara
In this study, we have measured the negative ion mobility in O2 at high pressures with a little amount of H2O concentration between 15 and 17,000 ppb. After that, we carried out a Monte Carlo simulation using mobility of electrons, that of the ions obtained in the measurements, and rate coefficients of ion-molecule reactions. As a result, the mobility value 2.39 cm2/V·s of O4¯ is obtained in ultrahigh
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Improvement in output power of vibration generators based on piezoelectric elements by using internal capacitor cancel control rectifier Electr. Eng. Jpn. (IF 0.4) Pub Date : 2023-02-05 Masataka Minami, Akito Nakagaki, Genki Hase
Recently, energy harvesting has attracted increasing attention. The present study focuses on vibration generators based on piezoelectric elements by proposing an internal capacitor cancel control (ICCC) rectifier to improve the output power. The proposed rectifier cancels the internal capacitor to improve the output power while retaining the maximum output power. Accordingly, this paper experimentally
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Modeling of I-V characteristics for crystalline silicon photovoltaic modules based on a simplified equivalent circuit and a temperature correction Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-11-21 Yuki Ohnishi, Yasuhito Takahashi, Koji Fujiwara, Kazuyuki Hidaka, Hiroshi Morita
Electric power generated by photovoltaic (PV) systems is generally unstable because of uncertain meteorological conditions. Stably maintaining the supply-demand balance of power systems requires an accurate prediction of the performance of PV systems. Especially for predicting the performance of the PV systems containing modules with different electrical characteristics or installed in different angles
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Development of the reciprocating airflow generator for wave power generator and study on the vertical axis turbine characteristics in reciprocating airflow Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-10-25 Kentaro Tsuji, Mitsuhiro Shiono
Renewable energy is attracting attention as an alternative to current mainstream power generator sources. One source of renewable energy is wave energy. We devised a simulator for the OWC-type wave power generator and developed a reciprocating airflow generator is generated reciprocating airflow by using the reciprocating motion of a piston. This piston motion was achieved by converting the rotational
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Limitation of switching frequency to improve characteristics and suppression of input current distortion for critical mode PFC Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-10-23 Ryuji Yamada, Ryunosuke Araumi, Keiji Wada
In critical mode power factor correction (PFC), the switching frequency is varied to achieve a sinusoidal input current waveform. Under certain conditions, a higher frequency increases the loss and noise. Meanwhile, the limitation of the switching frequency leads to an increase in input current distortion. This paper proposes a method to prevent an increase in distortion by compensating the pulse width
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Input voltage estimation method and suppression of distortion caused by DC voltage ripple for input current control of PFC Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-10-21 Ryuji Yamada, Ryunosuke Araumi, Keiji Wada
This paper proposes a new method for input current control of power factor correction (PFC) with continuous conduction mode (CCM), which does not require input voltage detection. As a control method that does not use input voltage detection, pulse width modulation (PWM) with the inductor current as the modulated signal is already in practical use however, this approach has limitations for the range
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MEMS Rogowski coil current sensor with spiral return coil Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-10-19 Yoshiyuki Watanabe, Mutsuto Kato, Toru Yahagi, Hiroki Murayama, Naoya Yamada, Kenichi Yoshida, Kenichi Maehara, Yusuke Fukuda, Kazuyuki Sashida, Katsuya Ikeda, Kosuke Ikeda, Toshiyuki Takemori
We have developed a MEMS Rogowski coil current sensor with spiral return coil. The Rogowski coil is formed on a silicon substrate clockwise and counterclockwise from the edges, for current detection and external magnetic noise compensation (device size 10 × 10 × 0.3 mm3, spiral coil 135 turns, via diameter 100 μm). When the slew rate (di/dt) was kept constant at 10 A/μs, and the current was changed
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Development of a hands-free electrolarynx for obtaining a human-like voice using the LPC residual wave Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-10-18 Masaki Takeuchi, Yutaro Soejima, Jaesol Ahn, Kunhak Lee, Ken Takaki, Tohru Ifukube, Ken-Ichiro Yabu, Shinnosuke Takamichi, Masaki Sekino
The conventional electrolarynx (EL) restores the voice of people who have lost their voice, however, its voice sounds like a robot and it occupies user's one hand. Therefore, we developed a hands-free wearable electrolarynx that improves the voice quality with the LPC residual wave as the vibration sound. Our device was able to reproduce sounds below 500 Hz, which is close to the fundamental frequency
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Microfabrication of surface acoustic wave devices with AlN thin film deposited on half-inch quartz wafer Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-10-14 Asahi Nagano, Kanato Kitamura, Shuichi Noda, Sunao Murakami, Kohei Iguchi, Sommawan Khumpuang, Shiro Hara
In this paper, we have fabricated surface acoustic wave (SAW) devices with six sets of interdigital transducers (IDTs) on half-inch wafers of quartz with deposited thin films of aluminum nitride (AlN). Firstly, AlN thin films have been deposited by reactive sputtering in Ar-N2 gas mixture at 400°C with the high-power impulse magnetron sputtering (HiPIMS) system which was developed for microfabrication
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Highly extendable passive current balancing interleaved high step-up boost converter using voltage multipliers Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-10-13 Kakeru Koyama, Masatoshi Uno, Hiroki Inohara
High step-up boost converters with large input current capacity are necessary for low-voltage renewable energy sources, such as photovoltaic panels and fuel cells. Interleaved converters are a suitable topology for low-voltage, large input current applications. Conventional interleaved converters, however, face a variety of challenges, such as the necessity of additional current control loops for active
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Development of a circuit breaker system using a linear motor with opposite magnetic poles Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-09-25 Yasuaki Aoyama, Yu Hasegawa, Katsuhiko Shiraishi, Hiroaki Hashimoto, Hajime Urai, Daisuke Ebisawa
The high-thrust linear motor with a lightweight and high-strength mover was developed for operating circuit breakers. The linear motor is composed of a lightweight mover that has permanent magnets sandwiched between magnetic poles and an armature with a three-dimensional magnetic circuit. The specifications and performance of the linear motor were determined to cut off current soundly. Then, a prototype
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Energy mix for net zero CO2 emissions by 2050 in Japan Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-09-20 Takashi Otsuki, Hideaki Obane, Yasuaki Kawakami, Kei Shimogori, Yuji Mizuno, Soichi Morimoto, Yuhji Matsuo
This study investigated cost-effective energy strategies for realizing net zero CO2 emissions in Japan by 2050, employing an energy system optimization model with hourly electricity balances. The detailed temporal resolution enables the model to capture the intermittency of variable renewable energy (VRE) and the costs of system integration measures. Siting constraints on VRE, such as prohibiting solar
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Verifying the calculation approach for radial suspension force based on the airgap flux density for SPM, consequent-pole, and bearingless AC homopolar motors Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-09-11 Takahiro Noguchi, Hiroya Sugimoto, Yusuke Fujii, Akira Chiba
In this paper, a calculation method is proposed for the radial suspension force of a bearingless motor with a surface-mounted permanent magnet (SPM) rotor, a consequent-pole permanent magnet (CPM) rotor, and a homopolar permanent rotor (HPM). The radial suspension forces are calculated mathematically and analytically using the airgap flux density. It was confirmed that the proposed radial force equations
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Novel dynamic wireless power transfer system using in-tire and in-wheel repeater coil for battery electric vehicles Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-09-08 Hayato Sumiya, Eisuke Takahashi, Nobuhisa Yamaguchi, Keisuke Tani, Osamu Shimizu, Sakahisa Nagai, Hiroshi Fujimoto, Daisuke Gunji, Isao Kuwayama
In order to improve the mileage per charge of battery electric vehicles (BEV), dynamic wireless power transfer systems are being developed. There are some problems such as is the wide gap between coils when mounted under the floor of a vehicle, and the effect of foreign objects between coils on power transmission. In-wheel coils, in which the coils are placed inside the wheel, have been proposed as
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A grid frequency control on small scale power system by introduction of variable speed diesel-driven power plant Electr. Eng. Jpn. (IF 0.4) Pub Date : 2022-09-08 Rion Takahashi, Atsushi Umemura, Junji Tamura
This paper proposes the application of an adjustable speed diesel engine-driven power plant employing a doubly-fed induction generator to an isolated small-scale power system including renewable power sources. This type of power plant can contribute to fast and flexible power balancing regulations under vacillating power supplies such as wind, solar, and other renewable power sources. Installation