著者

米村 恵一 杉浦 彰彦

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.122, no.8, pp.1272-1278, 2002-08-01 (Released:2008-12-19)

参考文献数

10

---

Recently, because aging is progressing in our country, cerebral disease is becoming a serious problem. Therefore, viewing this problem objectively, we can say support of aging and dementia patients is a very useful research theme. In this time, we examine the drinking condition as one noticing point in a case of carrying out the rank evaluation of dementia. Because it is generally known the condition like dementia by alcohol, dementia is deeply involved with alcohol. In this time's experiment, we examined the condition like dementia by alcohol. We carried out the experiment to observe an internal condition (cognitive ability) and an external condition (expression control ability) for the first stage and second stage in drinking level. First, by assessment of cognitive ability, though decline of cognitive ability by drinking occurs whole brain, it is shown to influence to left-brain in first step. Next, by assessment of expression control ability, we showed AU influenced by drinking in expression's output level. By these 2 experiments, we found out the concrete symptom of the condition like dementia by alcohol. In future, we examine the relationship between the condition like dementia by alcohol and dementia, and then we proceed advancing of rank evaluation of dementia.

著者

高瀬 斉

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会誌 = The journal of the Institute of Electrical Engineers of Japan (ISSN:13405551)

巻号頁・発行日

vol.117, no.6, 1997-05-20

著者

鈴木 守 石井 隆裕 神尾 光一 鈴木 浩 伊庭 健二

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.112, no.10, pp.937-944, 1992-10-20 (Released:2008-12-19)

参考文献数

9

被引用文献数

3

---

The idea of unbalanced load flow calculation was proposed many years ago. At that time, however, the needs for such techniques was not an urgent one. Modern power system networks are comprised of long untransposed transmission lines. Therefore, for some kinds of analysis, it is now almost impossible to treat a system as though it were a symmetrical network. The aims of most previous studies were oriented to solve voltage/current imbalance in local or small systems, as local imbalance was a serious concern. This is still an important issue, but more recently our needs have become concentrated on practical bulk power systems, since principal EHV lines are entirely untransposed. In this paper, the development of practical unbalanced load program and practical experience with it are reported. This program was developed for steady state analysis of large-scale practical networks under many possible unbalanced condition. The Newton-Raphson method in polar coordinates is used, since fast and moderate convergent characteristics are suitable for solving solutions. The program was applied to practical case studies. The models contain all of the 500 kV and most of the 275 kV overhead transmission lines in TEPCO. Since the density of the Jacobian matrix is higher than in single phase load flows, the number of non zero elements is extremely large. Convergent characteristics are excellent in all cases. The fear of numerical instability has been allayed.

著者

西前 順一 吉沢 憲治

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)

巻号頁・発行日

vol.112, no.1, pp.1-8, 1992-01-20 (Released:2008-07-15)

参考文献数

16

著者

林 重雄 川田 明 長澤 隆士 横山 尚登

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.112, no.11, pp.969-976, 1992-11-20 (Released:2008-12-19)

参考文献数

8

被引用文献数

1 3

---

The paper demonstrates that normal power system operating data may be used to determine the power-frequency characteristics in power system. Data are processed as random signals using spectral analysis techniques and the results estimate the generator and load power-frequency characteristics as transfer functions. The generator characteristics Kg is determined as a transfer function of the system in which input signals are frequency fluctuation ΔF and generator power setting signal ΔPg and output signal is generator power output ΔPe. For estimating the load characteristics Kl, there is a difficulty. There is a relation of ΔPl=ΔLo+KlΔF, between actual load ΔPl, ideal load under the state of nominal frequency ΔLo and fluctuation of system frequency ΔF. While, because it is impossible to measure ΔLo directly, ΔLo and KlΔF can not be separated. As to a partial system, when its capacity is small enough compared with the total system capacity, the contribution of ΔLo in a partial system to ΔF of the total system may be ignored, that is, ΔF and ΔLo are considered as independent phenomena. So, the cross-spectrum of ΔF and ΔLo decreases to zero according to the increase of data in number and Kl of the partial system can be estimated.

著者

Liudmila Popova Ke Ma Frede Blaabjerg Juha Pyrhonen

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

vol.4, no.4, pp.380-386, 2015-07-01 (Released:2015-07-01)

参考文献数

20

被引用文献数

2 5

---

Modular multilevel converter (MMC) is a recently emerged multilevel topology for high-voltage high-power applications. However, in wind power applications, to the best of the authors knowledge, the performance of the MMC has not been extensively investigated. In this paper, the application of the MMC to wind energy systems is studied. The converters used to connect the wind turbine to the grid, which have rated active powers of 2MW and 10MW, are proposed and investigated. The electrical losses and thermal loading of the power devices in the proposed converter solutions are analyzed based on the gird conditions/requirements for wind power. The efficiency of the MMC under different P/Q boundaries defined by grid codes is investigated and compared with two-level (2L) and three-level (3L) neutral point clamped converters. It is concluded that it is possible to use the MMC in wind power applications, and the losses are evenly distributed between the submodules of the MMC. However, inside a submodule, the losses of the power devices are not equal, which may lead to the de-rating of the converter.

著者

堀 洋一 内田 利之

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.109, no.7, pp.470-476, 1989-07-20 (Released:2008-12-19)

参考文献数

14

被引用文献数

1 2

著者

田村 博

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.111, no.12, pp.1000-1002, 1991-12-20 (Released:2008-12-19)

参考文献数

4

著者

戸張 和明 坂本 潔 岩路 善尚 金子 大吾 上松 初 大久保 智文

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 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society (ISSN:09136339)

巻号頁・発行日

vol.130, no.5, pp.614-624, 2010-05-01

参考文献数

8

被引用文献数

2 1

---

We propose a new beatless control mechanism for permanent-magnet synchronous motor (PMSM) drives. In drive systems, the three-phase voltage source induces a ripple component whose frequency is six times that of the voltage source frequency in the DC voltage. Therefore, if the motor frequency becomes six times the voltage frequency, a beat phenomenon, which causes an increase in the motor current ripple is observed. We analyze the beat phenomenon which causes current ripples and propose a method based on periodic disturbance current regulation, i.e., beatless control. We carry out time-domain simulation and various experiments and demonstrate the effectiveness of the proposed controller.

著者

稲荷田 聡 棚町 徳之助 仲田 清

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 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society (ISSN:09136339)

巻号頁・発行日

vol.121, no.11, pp.1169-1184, 2001-11-01

参考文献数

6

被引用文献数

2 5

---

In Power converter system for AC Electric cars, DC voltage contains a ripple component with a frequency twice as high as the line voltage frequency, because of the single-phase voltage source. Therefore, an inverter current ripple and a torque ripple of motors connected with the inverter in the power converter occur. The feedfoward beatless control can restrain the current ripple and the toque ripple has been proposed. It compensates the inverter frequency based on the ripple component of DC voltage. However, it is difficult to minimize the ripple component of the inverter and torque with the beatless control, because optimal compensation gain and phase depend on inverter frequency and other parameters. This paper proposes a feedback beatless control can minimize the torque ripple of the motors with the d-q transformation and the torque current ripple feedback and shows the effectiveness of the beatless control with an experimental result.

著者

斎藤 浩海

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.119, no.8-9, pp.897-900, 1999-08-01 (Released:2008-12-19)

参考文献数

28

被引用文献数

1 1

著者

秦 広 前田 孝 田川 直人

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.12, pp.1511-1516, 1997-11-20 (Released:2008-12-19)

参考文献数

10

---

As for traction motor for railway vehicle, over fifty thousands DC motors are used only in Japan Railways Companies. Insulation breakdown is one of the biggest problem for traction motor and various kind of insulation tests are carried out for every motors at the time of overhaul. The methods and the way of these insulation tests are determined about thirty years ago or more. Materials of insulation and how to compose these materials have progressed in these days. So it is important to research what kind of insulation test is suited for traction motor.This time we made a research to estimate various kinds of insulation tests by carrying out dielectric breakdown test for over 150 motors. And this paper describes the result.

著者

奥谷 民雄 島添 敏之

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.11, pp.1307-1314, 1999-11-01 (Released:2008-12-19)

参考文献数

20

---

This paper describes the development of a centralized interlocking system (CIS) for railway signalling and its evaluation in terms of safety and availability. The CIS is applied to the Ibara-line (41.7km) connecting Soja, Okayama Prefecture, and Kannabe, Hiroshima Prefecture, which began operations at January 11, 1999. The objectives in developing a CIS were to provide all the facilities available in both interlockings and a CTC (Centralized Traffic Control) system at significantly reduced cost while maintaining high levels of safety and reliability.The CIS is regarded as being divided into control center and lineside subsystems (see Fig.1). At the heart of the control center subsystem is the interlocking itself, which is a fail-safe multiple processor system. The lineside subsystem consists of the lineside data cable and trackside functional modules forming a fail-safe local area network.The trackside functional modules are connected to the control center subsystem which control them by trackside data links using single mode(SM) optical fiber cables. For the CIS we developed a long distance data transmission system by means of SM optical fiber technology, permitting a direct link over 20km without using a repeater.This system enables direct interlocking between starting signals reading into each end of a single line section. Furthermore, a train direction logic featuring a diversity train detection method that was produced in this development improves a safety level and a utilization rate in the single line signalling.

著者

林 重雄 米田 孝史 川田 明 長沢 隆士 森田 恵

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.113, no.11, pp.1231-1238, 1993-11-20 (Released:2008-12-19)

参考文献数

12

被引用文献数

1 1

---

It is important to include the behavior of load in studies of loss of generation and consequent load shedding and also in studies of long-term dynamics of a power system. This paper proposes a method which estimates load-frequency and load-voltage characteristic constants separately at the same time, by using normal operating data.The power system can be represented as an equivalent model which is composed of a major bus load, an equivalent impedance and a voltage source behind it. When the load capacity is small enough compared with the total system capacity, variations of active power of the load have little effect on frequency changes in the total system. Voltage changes behind the equivalent impedance are caused by variations of the operating condition in the external system, so voltage changes are independent to variations of active and reactive power of the major bus load under the state of nominal frequency and voltage. So coherences between them decreases to zero according to the increase of data in number and it is possible to estimate the load-frequency and load-voltage characteristic constants. Necessary measuring periods and accuracies of estimation are clarified and the effectiveness of the proposed method is verified by simulation results.

著者

中村 政俊 籏崎 裕章

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌. B (ISSN:03854213)

巻号頁・発行日

vol.97, no.7, pp.397-404, 1977-07-20 (Released:2008-12-19)

参考文献数

8

著者

一ノ瀬 貴士 浅見 隆 木村 隆幸

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.114, no.7-8, pp.715-722, 1994-07-20 (Released:2008-12-19)

参考文献数

2

被引用文献数

1 2

---

When a grid fails to be supplied with electric power, a photovoltaic generation system connected to the grid may possibly start islanding. Therefore, the photovoltaic generation system needs to have a protective equipment for detecting not only fault of the grid and the system but also islanding of the system. This paper describes the protective equipment that prevents the photovoltaic generation system connected to the grid from starting islanding. It does so by detecting (1) a periodical frequency variation of voltage caused at the connection by output of a reactive power variation of a photovoltaic inverter and (2) a rapid change of harmonic voltage caused by exciting characteristics of a pole transformer.

著者

垣本 直人 林 文杉 林 宗明

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.110, no.6, pp.495-503, 1990-06-20 (Released:2008-12-19)

参考文献数

8

---

In this paper, an expert system was developed for initial stage restoration of EHV power system from system blackout. The operations to be done in case of blackout, are usually determined at every electric station by operation rules, and the power system is restored to the prefault state by carrying out the determined operations at each electric station. In case a regular operation should not work well, several supplementary operations are prepared. This method has some merits that it can restore along normal operation state, that its logic is simple, etc. Because of these merits, a part of the operation rules have been automated by automatic restoration equipments, but in case of system blackout, such human judgements as to secure initial power source are required, and operations by commands from a load-dispatching office become dominant. In this paper, an outline of restoration process was firstly clarified through analysis of the operation rules. Next, the operation rules were transformed into production rules, and were put in order at every electric station. An individual knowledge base was prepared for each group of electric stations in construction of the expert system, and a proper order was introduced in choosing a station to be restored, by which vain search of rules was eliminated. The expert system was applied to a model power system, and it was shown that the computation time for generating all restoration operations is about 0.5s, and that the system can deal with cases where there are some damaged equipments.

著者

佐々木 鉄於 小山 泰史

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.121, no.4, pp.559-569, 2001-04-01 (Released:2008-12-19)

参考文献数

4

---

We study the voltage stiffness effect for cascading tripping and its protection in power systems. This paper describes a new selective method of proper system separating point to prevent from system failure extension to wide area. We define “the voltage stiffness” by short circuit capacity and line impedance, and explain an operation to select proper separation point. In addition, we consider the security after system separations. It is dominated by both increase of reactive power transmission losses and margin of reactive power supply of generator. The basic 4 power system structures are also considered in this paper. The topological analysis of power system can show the best system structure in both power interchange and cascading trip protection. We apply the proposed method to practical power systems and simulate power system faults. Simulation results show that separating system at the selected point can defend cascading tripping.

著者

佐々木 正明 川人 祥二 田所 嘉昭

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌C(電子・情報・システム部門誌) (ISSN:03854221)

巻号頁・発行日

vol.121, no.8, pp.1312-1317, 2001-08-01 (Released:2008-12-19)

参考文献数

14

---

This paper presents a method for integrating gamma correction and gain control functions on a CMOS image sensor with logarithmic response. The proposed method is based on a fact that gain variation and level shifting in logarithmic compressed domain are equivalent to the gamma correction and the gain control, respectively, in the exponentially expanded domain. The prototype chip integrating proposed function is fabricated with triple-metal double poly-silicon n-well 0.6μm CMOS technology. As a result of calculation using measurement data of test circuits, the gamma value can be adjusted to 0.45 when the gain given in the logarithmic compressed domain is 0.741, and a gain of 20dB is obtained by the voltage level shift of 60mV.

著者

大槻 博司 横山 明彦 関根 泰次

出版者

The Institute of Electrical Engineers of Japan

雑誌

電気学会論文誌B(電力・エネルギー部門誌) (ISSN:03854213)

巻号頁・発行日

vol.112, no.7, pp.615-621, 1992-07-20 (Released:2008-12-19)

参考文献数

9

被引用文献数

1

---

Voltage instability is now under intensive study in Japan. It is very important to make clear the mechanisms of voltage collapse for the purpose of establishing the countermeasures.Voltage instability depends greatly on the dynamic characteristics of load and dynamic digital simulations are mainly adopted to analyze the dynamic phenomena of voltage collapse. In order to analyze the dynamic voltage stability, however, eigenvalue method has been already proposed by the authors, which requires a long computing time. In this paper, a simple method using “short-term P-Vcurves” is presented. It make it possible to show the power supply capability at any load nodes.A radial power system with 3 induction motors is analyzed and stability transition during voltage collapse is made clear. This phenomenon is useful for explaining the cascaded voltage collapse well.