著者
木方 靖二 塩野 光弘
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.112, no.6, pp.530-538, 1992
被引用文献数
11 4

This paper reports the method of electric power generation from tidal currents and test results of the system which is specially designed for this purpose. The system consists of a vertical axis turbine, a accelerator, an electric generator, and a control unit. The turbine is vertical axis Darrieus rotor, and has three blades. The real test in tidal currents was conducted from 1983 to 1988, at Kurushima straits, and its results are discussed.
著者
大塚 紳一郎 原 寛徳 小沢 慎治
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.124, no.4, pp.388-395, 2004 (Released:2004-07-01)
参考文献数
9
被引用文献数
2 4

Problem may arise when the drivers are unable to notice or late in noticing emergency vehicles due to the sealing nature of the vehicles, masking by the car audio system or car navigation operation, which poses a threat for common vehicles and emergency vehicles to collide at many crossing. Every minute, problem may arise at every crossing and it is dangerous to wait for the completion of the information infrastructure system, which requires suitable cost and time. Therefore, we propose a system for common vehicles, which detects emergency vehicles using microphone on-vehicle and produce warning information to the driver. In this research, our focus is for “Ambulance", “Fire Truck" and “Police Car". The siren for these vehicles is detected by means of a microphone on-vehicle. This project utilizes two microphones to in order to detect the direction in which incoming emergency vehicles are present. The system, which we propose, must be helpful to response quickly to emergency and rescue activities.
著者
榎本 裕治 鈴木 啓介 沖田 誠治 江藤 昂平 片山 英二
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.141, no.5, pp.423-430, 2021-05-01 (Released:2021-05-01)
参考文献数
25
被引用文献数
6

We have been studying the application of amorphous metals, which have a significantly lower loss than electrical steel sheets, to motors. Thus far, we have studied simple-shaped iron cores that can be machined only by shearing for radial motors. However, it is considered that the loss can be further reduced if the iron core is entirely made of amorphous metal. Here in this report, we report the results of a trial evaluation of a motor in which an amorphous metal is punched using a press die to form a stator core.
著者
赤木 泰文
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.108, no.8, pp.726-733, 1988-08-20 (Released:2008-12-19)
参考文献数
12
被引用文献数
2 2
著者
熊井 巧 青山 真大
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.141, no.4, pp.354-365, 2021-04-01 (Released:2021-04-01)
参考文献数
27
被引用文献数
4

This paper reports a variable flux PM motor based on a new principle of self-excitation utilizing space harmonics that are inevitably generated in concentrated winding structures. In addition, it has a passive variable flux function. Its rotor is composed of consequent poles for each N- and S-pole pair and self-excited wound-field poles. The effects of the passive variable flux function on the driving performance and its efficiency map are demonstrated via the prototype.
著者
寺山 祐樹 星 伸一
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.141, no.4, pp.366-373, 2021-04-01 (Released:2021-04-01)
参考文献数
20
被引用文献数
2

Undesirable torque ripples in permanent magnet synchronous motors occur because of the spatial harmonics of the inductance and permanent magnet fluxes. Previous studies have proposed several methods for suppressing these torque ripples based on mathematical models. However, most of them do not consider the magnetic saturation. Hence, the torque ripple estimation accuracy may deteriorate, and the torque ripple suppression performance is reduced in the magnetic saturation range. Therefore, this paper proposes a torque ripple suppression method by considering the magnetic saturation based on the estimated harmonic component of the flux linkage and clarification of its effectiveness through simulations and experiments. From the experimental results, the proposed method is seen to suppress the 6th-order torque ripple by 69.1%, which is higher than that of the conventional method. Therefore, it is verified that the proposed method can suppress torque ripples, including those in the magnetic saturation range.
著者
熊谷 崇宏 伊藤 健 西川 滉大 伊東 淳一 山根 和貴 山田 伸明 名和 政道
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.141, no.4, pp.313-323, 2021-04-01 (Released:2021-04-01)
参考文献数
41
被引用文献数
2

This study proposes a reduction method for iron loss in stator core using the optimum pulse pattern for a high-speed interior-permanent-magnet-synchronous-motor (IPMSM). In this paper, a simple evaluation function for iron loss of stator core in a pulse-width-modulation (PWM) drive is introduced. In particular, the iron loss in stator core is approximately estimated from the flux level obtained from the integral of the line-to-line voltage of the PWM drive. In addition, the pulse pattern is optimized to reduce the iron loss in stator core based on the introduced evaluation function. To validate the evaluation function, the correlation coefficient between the evaluation value and the measured iron loss is calculated in 12 random pulse patterns applied to the inductor and IPMSM. As a result, the correlation coefficients are 0.991 and 0.982 in the inductor and IPMSM, respectively. In addition, the iron loss of the IPMSM with the optimum pulse pattern is reduced by 8.5% and 3.7% in comparison with a carry-asynchronous PWM and carry-synchronous PWM, respectively.
著者
徳山 寛 和田 圭二 五箇 繁善
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.141, no.4, pp.324-329, 2021-04-01 (Released:2021-04-01)
参考文献数
21

In power converter circuits, a gate drive circuit is connected to the power devices for the switching operation. The gate drive circuit transmits both signal and power to the power devices, simultaneously. At present, multi-level converter circuits using large numbers of devices have been proposed for power electronics circuits, but these are complicated to implement in a circuit. Hence, simplification of the signal and power transmissions of the gate drive circuit is required for circuit implementations. This paper proposes a gate drive circuit using SAW (Surface Acoustic Wave) devices that can transmit signal and power to the power devices, simultaneously. To use the several-hundreds MHz signal output from the SAW filter as the gate signal, this paper presents the design procedure for the internal parameters of the detection circuit that demodulates the signal into a several kHz signal. The usefulness of the proposed design is demonstrated by experimental evaluation of a half-bridge inverter and gate drive circuit with SAW filters.
著者
渡辺 博巳 宮崎 聖 藤井 知生
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.110, no.11, pp.1193-1200, 1990-11-20 (Released:2008-12-19)
参考文献数
7
被引用文献数
5 14

A inverter-fed permanent magnet synchronous motor with a rotor position sensor and a speed sensor is used in many industrial applications as a DC-brushless motor. In this paper, a strategy which determines the rotor position and the speed of the permanent magnet synchronous motor by using the instantaneous values of phase voltage and phase current sensing is explained.In a permanent magnet synchronous motor, the permeance of the stater magnetic circuit is altered by rotating the rotor position; the inductance of a phase winding changes according to rotor positions. Hence, the phase voltages and currents of the motor have close relations with the rotor positions. Measured values of phase voltages and currents and the values of the equivalent circuit parameters are substituted to the voltage equation of the synchronous motor. Then, we can calculate the value of the rotor position angle by that voltage equation. The rotating speed of the rotor can be calculated from the voltage equation by substituting the rotor position angle. In these calculations, we used a 16-bit micro-computer and a DSP, and for sensing phase voltages and currents, 12-bit high quality A/D converters are used.Experimental results obtained by using the prototype system were congruous values of the rotor position angles and the rotating speed.
著者
萩原 善泰 西尾 敦彦 結城 和明 氏家 昭彦 高原 英明
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.119, no.5, pp.609-616, 1999-05-01 (Released:2008-12-19)
参考文献数
13
被引用文献数
1 2

For the better performance and/or the high speed running for electric rolling-stocks, high accuracy power factor control with PWM power converter fed by ac power line has become popular. It is practically easy to control actual power factor itself at the input point of the power converter on the rolling-stock, however, the more important is that at substations. Although there are some technical difficulties for detecting the correct voltage phase angle on the train, caused by, for example, interference from thyristor controlled converters, suitable target value for practical power factor can be calculated under reasonable conditions. Among some kinds of control concept, the instantaneous current control referring sinusoidal waveform is the most suitable solution for the Japanese Shinkansen. The test results proved the expected power factor control performance.
著者
根葉 保彦 古山 英二
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.117, no.9, pp.1092-1098, 1997-08-20 (Released:2008-12-19)
参考文献数
20
被引用文献数
2 3

In a utility interactive photovoltaic (PV) generating system, a PWM inverter is used for the connection between the PV arrays and the utility. The inverter is controlled to keep the output power at the maximum point for the PV. Although the PV power can be easily found by using the measured PV voltage and PV current, the installation of two detectors in the system is indispensable to obtain the exact PV power. In the system operation with the maximum power which is fed into the utility, the PV does not always operate at the maximum point of the PV output power because of the power losses in the system. It has been reported that the use of the measured ac voltage or ac current in the inverter output side can exclude the system losses from consideration and achieve the system operation with the maximum utility power. In this manner, however, since the ac output waveforms of the PWM inverter consist of many pulse trains, the filter circuit may be necessary for the detector to get the exact values of the ac output.This paper proposes a calculation method of the utility power in the PV generating system by using a PWM current source inverter. In this system, the PV current only is measured and is employed for the power calculation combining the control parameter of the PWM inverter. As the proposed manner monitors the utility power instead of the PV power, the control which does not need to take the system losses into consideration can be achieved. This paper presents the calculation method of the power for the single-phase inverter-PV system and gives the experimental basic characteristics. Moreover, the application of the proposed manner to the three-phase PWM inverter-PV system is shown and the experimental results are given.
著者
古賀 俊作 北野 淳一 関 秋生 中島 強
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.119, no.6, pp.895-900, 1999-06-01 (Released:2008-12-19)
参考文献数
5

In the Yamanashi Maglev Test Line, LSM is controlled with the PI controller of velocity and phase locked loop. This controller includes integrating action and compensates the position steady-state error and velocity steady-state error. Therefore the Maglev train can be controlled according to the velocity pattern accurately and the error of stopping position is within 2.5cm. Power Conversion Substation of South Group converts the power in frequency (0-46.3Hz), current (0-1015A) and in voltage (0-6, 350V). The Maglev train is controlled within these limits. However when the train accelerates and reduces maximally, it needs the power more than the limits. Naturally output power is limited within the limits, the performance of the control system is getting worse. For concrete example, at the transition from acceleration to even speed or from reduction to even speed, the overshoot or undershoot of the speed occurs. If this condition occurs at the stopping, the train moves back. These movement are not so good for the riding comfort.In this paper, we propose the Improvement method of integrating action in case of the saturation of output current. Firstly we report the configuration and basic characteristics of the method, and then we show the experiment results .
著者
船渡 寛人 神山 健三 河村 篤男
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.119, no.4, pp.550-551, 1999-04-01 (Released:2008-12-19)
参考文献数
2

The authors have proposed the VAPAR (Variable Active-Passive Reactance Circuit) which can generate not only a positive reactance but also a negative reactance applicable to a power circuit. To help understanding of a negative inductance, at first, the difference between a negative inductance and a capacitance is clarified by demonstrating simulations of series LCR and LLnR(Ln<0) circuits. Then the characteristics of the negative inductance is also exemplified by a dynamic model using a motor-assisted bicycle.
著者
加納 善明 小坂 卓 松井 信行 中西 俊人
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.135, no.6, pp.725-733, 2015-06-01 (Released:2015-06-01)
参考文献数
26
被引用文献数
1

This paper presents a torque ripple reduction design of a concentrated-winding IPMSM with a new flux barrier for saliency-based sensorless drives. The proposed IPMSM is designed for use in general-purpose sensorless industrial drives. In order to reduce torque ripple, its rotor employs a V-shape-magnet arrangement and circular flux barrier which is placed at the center of a rotor yoke between N- and S-poles. A 45-Nm 5.5-kW IPMSM is manufactured as a prototype in order to confirm the design validity, and experimental studies using the prototype demonstrate the expected drive characteristics and validate the proposed design procedure.
著者
徳永 紀一 松田 靖夫 石山 国雄 天野 比佐雄
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.110, no.5, pp.447-456, 1990-05-20 (Released:2008-12-19)
参考文献数
11
被引用文献数
1 1

Recently resonant inverter type power supplies for microwave ovens have been examined, but the stability of the filament temperature and the loss of the transformer have not been examined in detail.We studied the relation between circuit parameters and the characteristics of the power supply. As a result we conclude that putting a resonant reactor in the primary side of the transformer brings better stability of the magnetron filament temperature and lighter duty of the circuit elements than putting it in the secondary side.Newly-developed power supply can be continuously controlled in the range of 5 to 100%. Its efficiency is about 85% which is about 2% higher than that of the conventional one. Moreover the weight is reduced to about 1/4.
著者
加藤 司 長山 格 玉城 史朗
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.141, no.2, pp.161-167, 2021

<p>We developed a fishery and marine skill learning support system as a self-training teaching material. In this study, we evaluated the usefulness of the proposed system by using text mining and searched for the points to be improved in this system. Using this system, we conducted a survey among the students of a fisheries high school using an evaluation sheet with free-form answering. From the results, we extracted five points, namely "learning method using this system", "video operation and technology confirmation", "promotion of understanding by this system", "skill learning at home", and "fun to learn fisheries skills". Among these five points, "promotion of understanding by this system", in which an understanding of the skill is promoted through explanations of skill and skill videos, was evaluated positively. It was also found that a review is effective in utilizing this system. As a point to be improved, it was found that narration should be provided along with the presentation of the subtitles.</p>
著者
城間 康 安富祖 仁 斎藤 秀和 長山 格 玉城 史朗
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌D(産業応用部門誌) (ISSN:09136339)
巻号頁・発行日
vol.141, no.2, pp.168-172, 2021

<p>The grade of a mango is determined by its color. Traditionally, the classification of mangoes is manually performed by humans. Such classification is subjective and then the quality of mango's is not uniform. In order to overcome the problem, automatic classification method to classify mango based on RGB histogram of their images and certain threshold. However, this process might be influenced by variations in the luminance. In this study, we implemented alternatives of the traditional method and compared them with sampled images.</p>