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.
著者
道上 勉 鬼塚 長徳 北村 哲
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.11, pp.887-894, 1990-11-20 (Released:2008-12-19)
参考文献数
5

The previous generator excitation control system is based on AVR control of generator terminal voltage. This system can't accommodate reactive power up to the facility limit even when the power system voltage decreases to the limit for stable operation. We attempted to develop advanced excitation control system (PSVR) to achieve higher constant sending end voltage of power station. We intended to apply the system to the generator connected to a 500kV system which contributes most effectively to the voltage stability of a bulk power transmission system. This PSVR produces higher control gains than the AVR, the following functions were adopted: (1) AVR gain reduction circuit, (2) phase compensation circuit, and (3) damping improvement by enlarging the limiter of the PSS. In addition, various functions were provided. These include voltage slope characteristics to balance the reactive power of adjacent generators and PSVR output and terminal voltage limiter to stabilize the generator operation. Previously to an application to a real system, a transient response test was performed by combining PSVR and generator simulator to verify the damping improvement and stability of the voltage control.
著者
田村 淳二 上野 昌裕 米岡 智 上田 善之
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.120, no.12, pp.1636-1645, 2000-12-01 (Released:2008-12-19)
参考文献数
16
被引用文献数
2 5

Recently the wind power generation has attracted special interest and many wind power stations are being in service in world. In the wind power stations, induction machines are mostly used as a generator. Since induction machines also have a stabi problem like the transient stability of synchronous machines, it is important to analyze the transient stability of power system includ wind power stations. This paper presents a model of induction generators, develops methods of power flow calculation and transi stability simulation of power system including induction generators, and presents considerations on the characteristics of transi stability of induction generators on the basis of numerical simulations.
著者
松尾 豊 横山 明彦
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.120, no.8-9, pp.1061-1070, 2000-08-01 (Released:2008-12-19)
参考文献数
6
被引用文献数
2

FACTS devices such as high-speed phase shifter and variable series capacitor enable us to control active power flow in order to avoid thermal constraints on transmission lines, resulting in an increase of the network loadability and a reduction of production cost. However where to place these devices is an essential matter because their effects considerably depend on the locations. From an economic point of view, the investment cost must be taken into account as well as the reduction of the production cost. Therefore we propose to maximize return on investment (ROI) by searching not only the best location of FACTS devices but also the rating of each device. This problem is expressed as combinatorial optimization problem nested by nonlinear optimization problem. To solve this problem, tabu search incorporated with nonlinear programming method is used. And we discuss the remedial control of FACTS devices and simultaneous consideration of multiple load conditions. By considering remedial control, we can make better use of FACTS devices. Multiple load conditions bring us more appropriate solutions. Because the consideration makes our problem more difficult to solve, some efforts are necessary to be made. Numerical results are shown for a 3-generater 41-line model system and a 5-generator 42-line model sysytem.
著者
中山 正人 福田 健一 荒木 拓人 恩田 和夫
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society (ISSN:03854213)
巻号頁・発行日
vol.125, no.2, pp.213-220, 2005-02-01
参考文献数
11
被引用文献数
2 2

The secondary batteries for the electric vehicle (EV) generate much heat during rapid charge and discharge cycles, when the EV starts quickly consuming the battery power and stops suddenly recovering the inertia energy. The generated heat increases significantly the cell temperature and causes possibly bad influences on the battery performance and the safely requirement. So we have studied the thermal behavior of nickel/metal hydride (Ni/MH) battery during rapid charge and discharge cycles, applying our previous battery thermal model, which have been confirmed to agree with the experimental results at smaller charge current than the rated current. The heat sources by the entropy change, the hydrogen occlusion and the side reaction have been referred to the published data, and the overpotential resistance and the current efficiency, the ratio of main reaction current to charge current, have been measured experimentally through the rapid charge and discharge characteristics with constant current. By using these data our thermal model for Ni/MH battery has estimated its temperature increase, which agrees well with the measured temperature rise, with the root mean square error of 1.5°C and 2.1°C for charge and discharge cycles, respectively.
著者
本橋 準 一ノ瀬 貴士 石川 忠夫 甲斐 隆章 金田 裕敏 石塚 隆司
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.1, pp.14-23, 1999-01-01 (Released:2008-12-19)
参考文献数
10

In recent years, enhancement of consciousness for energy saving and problem of environment are widely encouraging the installation of dispersed storage and generation (DSG) units such as co-generation and photo-voltaic generation. When a distribution line with the DSG is disconnected from the main source of utility, the DSG supplies power to the distribution line. The situation, namely islanding, creates various problems for the reliable and safe operation of the distribution line. Thus, the islanding must be immediately prevented by islanding protection equipment. This paper describes an islanding protection scheme and the digital protection equipment for a synchronous generator. The proposed scheme detects an islanding of a synchronous generator from frequency fluctuation occurred by feeding a sinusoidal small reference voltage signal into the auto voltage regulator circuit of the generator. The authors have manufactured the digital protection equipment applying the scheme, confirmed the excellent performance by testing in an artificial distribution line. In the paper, a determining proceeding of the setting value of the equipment is described.
著者
吉田 義昭 鈴木 宏和 藤原 耕二 石原 好之
出版者
一般社団法人 電気学会
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.134, no.5, pp.399-411, 2014 (Released:2014-05-01)
参考文献数
29

It is important that PV systems detect islanding caused by power system fault to ensure electrical safety. So, we propose a novel islanding detection method which detects harmonic impedance by injecting the harmonic currents synchronized with exciting current harmonics of the pole transformer. In case that an induction motor load is included in the load system, the basic experiments of islanding detection and simulation analysis are conducted to verify the effectiveness of the proposed method.
著者
小島 康弘 中村 静香 阿部 公哉 高橋 修 塚田 英一 黒川 隆久
出版者
一般社団法人 電気学会
雑誌
電気学会論文誌. B, 電力・エネルギー部門誌 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society (ISSN:03854213)
巻号頁・発行日
vol.125, no.2, pp.170-176, 2005-02-01
参考文献数
6
被引用文献数
4 2

This paper presents a newly developed EDC (Economic Dispatching Control) function for Tohoku EPCO's new EMS system. In this new EDC, we can minimize total fuel cost under system security constraints such as "AFC margin considering band width and ramp rate in future band changing schedule" and "power flow constraint considering future maintenance schedule". We formulate EDC problem as "continuous variable (generator output) optimization" under "combinatorial optimization of band schedule". To optimize this problem, Problem Space Search method and interior point QP method are adopted. Test results and the actual operation show that, this new EDC can follow against steep increase and decrease of electric demand cooperating with AFC. This EDC has been operating successfully in Tohoku EPCO since June 2003.
著者
小島 康弘 古塩 正展 中村 静香
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 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society (ISSN:03854213)
巻号頁・発行日
vol.128, no.2, pp.429-436, 2008-02-01
参考文献数
10
被引用文献数
15 18

Photovoltaic (PV) and Wind Turbine (WT) generation systems are expected to offer solutions to reduce green house gases and become more widely used in the future. However, the chief technical drawback of using these kinds of weather-dependent generators is the difficulty of forecasting their output, which can have negative impacts on commercial grids if a large number of them are introduced. Thus, this problem may hinder the wider application of PV and WT generation systems. The Regional Power Grid with Renewable Energy Resources Project was launched to seek a solution to this problem.<br>The scope of the project is to develop, operate, and evaluate a Dispersed Renewable Energy Supply System with the ability to adapt the total energy output in response to changes in weather and demand. Such a system would reduce the impact that PV and WT generation systems have on commercial grids and allow the interconnection of more Dispersed Energy Resources (DER). In other words, the main objective of this project is to demonstrate an integrated energy management system, or a type of microgrid [1], as a new way of introducing DERs. The system has been in operation since October 2005 and will continue operation until March 2008. Through the project period, the data on power quality, system efficiency, operation cost, and environmental burden will be gathered and a cost-benefit analysis of the system will be undertaken.<br>In this paper, firstly we introduce the concept of microgrid for reducing negative impact of natural energy, and secondly illustrate the structure of electric and thermal supply control system for Microgrid, especially for the Hachinohe demonstration project. The control system consists of four stages; weekly operation planning, economic dispatching control, tie-line control and local frequency control. And finally demonstration results and evaluation results are shown.
著者
宮嵜 悟 石井 勝 馬場 吉弘
出版者
一般社団法人 電気学会
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.125, no.5, pp.544-550, 2005 (Released:2005-08-01)
参考文献数
17
被引用文献数
2 1

A lightning return stroke model is indispensable in calculating electromagnetic field associated with a return stroke. A lot of return stroke models have been proposed, however, no model has ever succeeded in reproducing all the features of typical electromagnetic field waveforms at various distances. In this paper, two return stroke models are proposed. One is a Transmission-Line type model, and the other is modification of Diendorfer-Uman model. These models successfully reproduce all the features of typical electromagnetic field observed on ground.
著者
小枝 一彦 造賀 芳文 上山 哲平 餘利野 直人 佐々木 博司
出版者
一般社団法人 電気学会
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.126, no.8, pp.789-797, 2006 (Released:2006-11-01)
参考文献数
20
被引用文献数
5 7

This paper proposes a new framework of distribution system planning under the condition of mass installed Distributed Generators (DGs). At present, distribution system planners do not pay much attention to the interconnection of DGs. However, if some DGs can supply power instead of conventional power stations, they will give a significant impact. The planners will have a new option to build a network system plan without unnecessary investment to distribution networks. In this study, an objective function for distribution system planning is formulated to obtain maximum profits for utilities, and the authors discuss reduction of the utilities' investment cost and distribution system loss for installation of DGs. In addition, the authors propose a solution method using a genetic algorithm technique in order to find quasi-optimal solutions for large scale problems. Furthermore, the authors also discuss the connection tariff in order to increase the utilization rate of distribution networks. The advantage of the proposed method is demonstrated through several numerical simulations with successful results.
著者
神永 建二 武田 直樹 片貝 昭史 村田 義直 金岡 護 高橋 憲司
出版者
一般社団法人 電気学会
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.117, no.1, pp.92-100, 1996-12-20 (Released:2008-12-19)
参考文献数
8

To evaluate the suitability of the DC withstand test for use as the after-laying test for extrahigh-voltage XLPE cable lines, especially 500-kV XLPE cable lines, we studied the effectiveness of the DC withstand test and the influence of DC voltage application on AC insulating performance, using XLPE cables with artificial defects. DC breakdown strength of the cable with defects does not decrease radically compared with AC breakdown strength due to space charge effects. The defects that are detected by the AC withstand test might not be detected by the DC withstand test and short-circuited trees may appear at earthing after the DC withstand test, degrading the AC insulating performance. The DC withstand test should therefore not be used as the after-laying test for 500-kV XLPE cable lines.
著者
朴 大欽 土井 雄介 石田 政義
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 = The transactions of the Institute of Electrical Engineers of Japan. B, A publication of Power and Energy Society (ISSN:03854213)
巻号頁・発行日
vol.131, no.7, pp.621-629, 2011-07-01

So far, as a part of NaBH<sub>4</sub>-H<sub>2</sub>-Fuel Cell study we have been through optimization of hydrogen production reactor size and operating conditions to reach 100% of hydrogen production rate. Moreover, the potential of NaBH<sub>4</sub>-H<sub>2</sub>-Fuel Cells were verified by testing a 1000mL pressurebuffer for steady hydrogen supply under variable load conditions within maximum limit of 1.2kW. However, the buffer used gives rise to decreased energy density of the system due to its big size relatively to other components. Hence, minimized buffer volume under the limit of applied conditions is required to compact the system. In this study, the pressurebuffer volume which satisfies load following as well as compact size is found. Load following ability is approved as a result of hydrogen generation system operation, which has 325mL and 170mL buffer volume at 0°C and 20°C respectively within load variation of the average load 700W, peak load 1200W and 2 seconds of load cycle. Furthermore, NaBH<sub>4</sub>-H<sub>2</sub>-Fuel Cell's energy density is calculated. At last, all these come into the result that NaBH<sub>4</sub>-H<sub>2</sub>-Fuel Cell has high usefulnessas a high density mobile power source over 2.7kWh.