著者
森實 俊充 木村 紀之 大森 英樹
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.134, no.10, pp.NL10_3, 2014 (Released:2014-10-01)

Our research focuses on the power conversion system and the electrical machinery system based on the powerelectronics technology. Our research group consists of three laboratories. Three faculty members, 38 students are with the research group.
著者
池田 吉堯 坂井 六三郎 浅野 一明 坂本 隆行
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.115, no.4, pp.379-386, 1995-03-20 (Released:2008-12-19)
参考文献数
7

The resonant DC link invertors have been developed these years for avoiding the switching loss of the conventional multi-pulse PWM invertors. This paper proposes a three phase VVVF power invertor using resonant pulse density modulation for induction motor speed-control. The invertor is composed of a cascade connection of a resonant DC-DC convertor and a multi-pulse PWM invertor. The output waveform depends on the gate pulse patterns of the invertor valves. This paper proposes three kinds of pulse patterns for obtaining the outputs of trapezoidal waveform and of sinusoidal waveform, and describes also the experimental results. The V/f characteristics for induction motor speed-control and the regenerative braking operation will be examined and the circuit behaviors will be discussed.
著者
小鹿 聡士 坂下 友一 笈川 信一郎
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.139, no.12, pp.998-1004, 2019-12-01 (Released:2019-12-01)
参考文献数
12

In the conventional bus voltage controller, the concentration of heat generation in a specified circuit has been an obstacle to miniaturization. In this paper, we describe the control algorithm and the experimental result of the direct and distributed switching control (DDSC) method devised to disperse the generation of heat. Additionally, to improve the transient response while reducing the steady state switching frequency, which can reduce the generation of heat, we investigated the application of a transient mode that temporarily speeds up the control cycle when load fluctuation is detected. We also report the calculation of the heat reduction effect that can be achieved by combining these methods.
著者
中沢 洋介 戸田 伸一 安岡 育雄
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.118, no.9, pp.1071-1080, 1998-09-01 (Released:2008-12-19)
参考文献数
8
被引用文献数
8 14

This paper presents a new vector control for induction motor drives in full block mode, so called One-Pulse mode, of inverters. For traction drives the inverter usually operates in this mode in a high speed region. The amplitude of voltage vector is restricted constant in the mode. The conventional vector control is not applicable as it requires controllability of both the amplitude and the phase of the voltage vector for all time. The proposed scheme provides quick torque response even in the One-Pulse mode. Experimental results are shown to validate the effectiveness of the control.
著者
井上 雅理 道木 慎二
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.139, no.7, pp.637-644, 2019-07-01 (Released:2019-07-01)
参考文献数
7
被引用文献数
2

This paper describes a new discrete-time PMSM model for the discrete design of current vector control systems. The discrete design of current control system minimizes the discretization error and improves the current control performance at the sampling point. The conventional PMSM model discretization method presumes that park transformation runs continuously. When the sampling frequency is considerably lower than the fundamental electric frequency, this assumption is invalid and the control performance will degrade due to modeling error. In this paper, the authors propose a method of PMSM model discretization considering discrete-time park transformation and design an additional cross-coupling compensator for the proposed model. The experimetntation results demonstrate the effectiveness of the proposed model.
著者
関口 貴哉 清水 敏久
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.139, no.8, pp.761-762, 2019-08-01 (Released:2019-08-01)
参考文献数
3

Various studies have been conducted on photovoltaic (PV) power generation systems that focus either on a generation control circuit (GCC) to prevent power reduction due to a partial shade or on an active power decoupling method (APD) to reduce the power pulsation with twice the utility frequency. However, to the best of the authors' knowledge, only few studies have examined the PV power generation systems in which both the GCC and the APD functions are installed. In this paper, a novel PV power generation system equipped with both the GCC and the APD functions is proposed, and its fundamental operation is verified.
著者
和田 圭二 平尾 高志
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.139, no.8, pp.765-766, 2019-08-01 (Released:2019-08-01)
参考文献数
4

This letter proposes a single-phase full-bridge inverter with a capacitor embedded in a bus bar. In order to reduce the switching ripple flowing in the electrolytic capacitor, the proposed structure embeds a barium titanate (BaTiO3) ceramic capacitor in the bus bar. The experimental results verified the operation of the inverter circuit, rated 300V, 4.1A with a switching frequency of 100kHz.
著者
佐藤 貴彦 新明 脩平 仲里 三希 見上 慧 佐藤 智矢 境野 翔 大西 公平
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.131, no.3, pp.283-290, 2011-03-01 (Released:2011-03-01)
参考文献数
19

This paper proposes a knee stretch walking method for biped robots; the method involves the use of the toes and heel joints to increase walking strides. A knee can be stretched by switching control variables. By a knee stretch walking with heel contacts to the ground and toe takeoffs from the ground, biped robots can increase their walking stride and speed. The validity of the proposed method is confirmed by simulation and experimental results.
著者
長谷 伸一 持永 芳文 八木 英行 江本 政春
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.118, no.7-8, pp.930-936, 1998-07-01 (Released:2008-12-19)
参考文献数
8

Takasaki-Nagano section, a part of Hokuriku Shinkansen was opened in October, 1997, just before Nagano Winter Olympics. Hokuriku Shinkansen has been electrified by 30kV a. c. commercial frequency AT feeding system.As for the commercial frequency, Japan is divided into two zones: the western part of Japan is a 60Hz zone and its eastern part is a 50Hz zone. Two different power frequencies exist in Hokuriku Shinkansen which passes power frequency borders between different electric power companies. Therefore, in case of a contact fault between two different power frequencies, a beat-formed large fault current will flow, which should be immediately detected and cut off.At present, a distance relay and an AC ΔI type relay are used as protective relays for a feeding circuit of Shinkansen lines. However, it was experimentally made clear that those relays do not operate by a beat-formed fault current which appears in the case of a contact fault between two different power frequencies. For this reason, we have developed and put to practical use a protective relay for a contact fault between two different frequencies, which operates by detecting 55Hz component peculiar to the current caused by the contact fault and also detecting power frequency of an opponent traction substation.They have been installed at a frequency-bordered sectioning post and at traction substations which sandwich the sectioning post.
著者
桂 誠一郎 大西 公平
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.123, no.11, pp.1371-1376, 2003 (Released:2004-06-18)
参考文献数
10
被引用文献数
9 15

Minimally invasive surgery (MIS) which thinks a great deal of patient’s quality of life (QOL) has attracted attention during about ten years. In this paper, it aims at development of the technology for transmitting force sensation required in medical treatment especially through surgical instruments, such as forceps. In bilateral control, it is a problem how master and slave robots realize the law of action and reaction to the environment. Mechanism of contact with environment and bilateral controller based on stiffness are shown. Master arm in contact with human and slave arm in contact with environment are given compliance, and stable contact with environment can be realized. The proposed method is applied to 3-link master-slave manipulators. As a result, transmission and reproduction of force sensation can be realized. The experimental results show viability of the proposed method.
著者
東 聖 伊藤 大介 石田 貴仁 岩田 明彦 菅原 賢悟 森本 茂雄
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.139, no.5, pp.495-502, 2019-05-01 (Released:2019-05-01)
参考文献数
15
被引用文献数
2

This paper proposes countermeasures to reduce radiated AM radio frequency noise caused by the VVVF (variable-voltage/variable-frequency) inverter system incorporated with an electric railway car. First, the common-mode current flowing through a cooling fin earth line is studied, and the connection change of the line shows good attenuation of the 1.26MHz resonance component. Second, the common-mode current flowing though the motor earth line with a capacitor is focused upon, and the modified connections of the line to the outside of the input common-mode core achieves fine noise reduction in the range from 500kHz to 1.5MHz. In such cases, the existing input common-mode core is utilized to establish the impedance, which is efficient in both the noise reduction and the countermeasure cost reduction. Finally, a current simulation model which is paid attention to the AM radio frequency range is examined with the measured impedance data of the VVVF inverter system. The currents flowing thorough the cooling fin earth line and the motor earth line is simulated, and these simulated currents show good agreement with the measured one.
著者
持永 芳文 浜田 博徳 新井 浩一
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.1, pp.41-50, 1990-01-20 (Released:2008-12-19)
参考文献数
6
被引用文献数
1

In the single-phase AC railroad electrification, the voltage unbalance of three-phase electric power system has to be reduced. For this purpose, three-phase power is converted to two-phase power by the Scott-connected transformer, and the electric power is received from a powerful or high-tension source.Recently, regenerative braking has come to be applied to electric rolling-stocks, but occasionally the regenerative brake increases the voltage unbalance in the three-phase electric power source with the ordinary two-phase feeding system. So, in some cases unbalance power compensation may be found more profitable than the Scott-connected transformer.This paper describes a theoretical study and results of a test on a mini-model which uses a scalene Scott-connected transformer, switched reactors and capacitors for the purpose of reducing the voltage unbalance in the three-phase electric power source. By this method, main phase (M) and teaser transformer (T) voltages of scalene Scott-connected transformer secondary side are decided by a single load power factor, and the sum of the capacities of the reactors and the capacitors is equal to the apparent power of single-phase load.For example in SCR switched control of the reactors/capacitors which has four steps in power running and two steps in regenerative braking, the voltage unbalance in the three-phase electric power source can be reduced satisfactorily.
著者
山口 仁 渡部 俊春 山田 一
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.116, no.1, pp.94-99, 1995-12-20 (Released:2008-12-19)
参考文献数
10
被引用文献数
1 1

Force between an electromagnet and an iron piece is usually calculated with a equation of Maxwell's stress, and for the exact result, the integration of stress is made along a route away from the iron. It, however, is necessary to calculate magnetic flux density components paralell to the integration route as well as perpendicular ones.The authors propose a new method of calculation using FEM. This method presents that the integration of Maxwell's stress is made on the surface of an iron piece, and magnetic flux is regarded perpendicular to the iron surface. Calculated values of magnetic force, attractive force and restoring force under small parallel displacement to pole face, have been compared with measured ones on an experimental model. The following results are obtained. (1) The magnetic force is calculated using the results of FEM analyses where the number of nodes has been less than 1000. The differences between the calculated and the measured values are smaller than 5%. (2) To obtain the above results, it is necessary that relative permeability of the iron piece is larger than 100 and the side length of each triangle element near the iron corner is less than 2% of the gap length.
著者
織田 利彦
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.125, no.8, pp.800-807, 2005 (Released:2005-11-01)
参考文献数
7
被引用文献数
1 1

In traditional coordinated traffic signal control on an urban road network, the following two problems have been known. First, the conventional method involves a time lag between traffic measurement and signal control. Second, an abrupt switching of control parameters throws the traffic flow into disorder.This paper proposes a new approach to avoid these problems. We increase the frequency of switching. The control parameters are switched as frequent as every two cycles. At the time of switching, minor variations of the on-going plan are generated. For each variation of plan, traffic delay at each intersection is predicted based on measured traffic data at up-stream detectors. Then the plan minimizing the delay is chosen to be the control parameters in the next cycle. In order to evaluate the validity of this approach, experiments were carried out using a traffic simulator. The experiments indicate that the proposed method reduces the queue length significantly, compared with the conventional method.
著者
大隅 英貴 安部 恵介 阿部 健一
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.116, no.4, pp.471-476, 1996-03-20 (Released:2008-12-19)
参考文献数
8

Recently in the conurbation area, traffic congestion on railway system is very terrific and the commutation area have been spread out year after year. So it is required to reduce traffic congestion and to shorten time to arrive at the destinations. Recent development of information system in a railway system makes it possible to know more accurate passengers demand in real time. In this paper, we propose a method to make more flexible train schedule based on passengers demand. The proposed method can make a train schedule to satisfy the most amount of demand and make the total trip time of passengers smallest. By setting number of trains and their start times, stop patterns of trains are automatically generated and evaluated by train traffic simulations and passengers flow simulations. These simulations are executed repeatedly to evaluate trial schedules in the planning process and so efficient simulation methods are also proposed. The effectiveness of the proposed method is examined through some examples of applications based on practical railway models.