著者

辻本 富幸 中出 雅彦 八木 幸弘 石井 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 = 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.126, no.4, pp.421-426, 2006-04-01

被引用文献数

3

---

Water tree is one of the degradation aspects of XLPE cables used for under-ground distribution or transmission lines. We have developed the loss current method using 3rd harmonic in AC loss current for cable diagnosis. Harmonic components in loss current arise as a result of the non-linear voltage-current characteristics of water trees. We confirmed that the 3rd harmonic in AC loss current had good correlation with water tree growth and break down strength. After that, we have applied this method to the actual 66kV XLPE cable lines. Up to now, the number of the application results is more than 130 lines.<br>In case of cable lines terminated at gas-insulated switchgear (GIS), we have to remove the lightning arrestor (LA) and the potential transformer (PT) out of the test circuit. The reason is that we are afraid that each of LA and PT disturbs the degradation signal from cable lines. It takes extra time (1 or 2 days) and costs more to remove LA and PT in GIS out of a circuit. In order to achieve easy and reasonable diagnosis, we have developed a new method for cable lines terminated at GIS, by utilizing a technique, which enables to reduce signal of LA and PT from disturbed signal of cable lines. We confirmed the effect of the new method by experiments with actual cables.

著者

江川 正尚

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.129, no.2, pp.253-256, 2009-02-01

被引用文献数

2 1

---

On July 23, 1987, a very hot day, the largest wide-area power outage occurred in Kanto-Area, Japan. The cause was a voltage collapse on the bulk power network of Tokyo Electric Power Company, due to the abnormal rate of demand rising following resume after lunch break. Aggressive studies on voltage collapse throughout industry and university have led to great advances in power system stability. This essay describes the detail record of the outage, the applied countermeasures, and the inside story when the multiple voltage solutions of power flow on actual power system were found out for the first time.

著者

倉石 英明 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 = 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.127, no.1, pp.28-40, 2007-01-01

被引用文献数

6 2

---

In order to keep power supply reliability at a certain level, electric power utilities have a certain amount of reserved capacity. When no generator outage or no unexpected large power demand occurs, however, the reserved capacity is regarded as surplus facility. To reduce the reserved capacity, some margin is reserved in tie lines between utilities. This margin is called Capacity Benefit Margin (CBM). In this study, a method of calculating optimal CBM in tie line under deregulated environment is described and two kind of optimal CBM are proposed. As a result, it is shown how the deregulation affects the optimal CBM by using numerical simulation for IEE Japan West 30 test system.

著者

林 泰弘

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.129, no.4, pp.491-494, 2009-04-01

被引用文献数

49 36

---

The number of installation of Distributed Generators (DG) such as photovoltaic and wind generations has been rapidly increasing in the world. Penetration of DG can contribute to reduce CO₂ emissions and conserve energy. On the other hand, since reverse power flow from DG to distribution system occurs exceed of the upper limit of adequate range of voltage, various voltage control methodologies have been proposed in order to keep voltage within the secure range. This paper describes several advanced voltage control technologies and shows the trend and future perspective about the control of distribution system with many DGs.

著者

川田 昌武 河崎 善一郎 松浦 虔士 川崎 誠

出版者

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.115, no.10, pp.1168-1173, 1995-09-20

被引用文献数

20

著者

浅岡 由伸 浅川 聡 横山 茂 中田 一夫 杉本 仁志

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.125, no.5, pp.537-543, 2005-05-01

被引用文献数

1 1

---

Omitting one phase's current limiting arcing horns on three-phase distribution lines has been applied since 1990's and contributes the costdown for lightning protective countermeasures. Moreover, in order to promote the costdown for the lightning protective countermeasures on single-phase distribution lines, we have investigated the methods omitting one phase's current limiting arcing horns on single-phase distribution lines.<br>When the single-phase distribution line omitting one phase's current limiting arcing horns branches or extends from three-phase distribution line omitting middle phase's current limiting arcing horns, there are possibilities that short circuits are generated between the single-phase distribution line and the three-phase distribution line by a direct lightning stroke.<br>In order to preventing the short circuits outage, we have clarified the conditions that sparkovers generated at some poles and that short circuits continued experimentally and analytically. Based on these conditions, we proposed some effective countermeasures for preventing the short circuits outage on single-phase distribution line omitting one phase's current limiting arcing horns.

著者

山田 哲 山城 迪 佐々木 正和 荒木 修一

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.123, no.8, pp.1011-1017, 2003-08-01

被引用文献数

12 8 11

---

Various models for the equivalent circuit of EDLC (Electric Double Layer Capacitor) have been presented so far. The multi-stage connection of RC circuit is a representative model to simulate the EDLC's charge-discharge characteristic. However, since high energy density type EDLC for electric power storage has the electrostatic capacity of thousands F, the phenomenon of being almost uninfluential for the case of conventional capacitor appears in an actual measurement notably. To overcome this difficulty, we develop an equivalent circuit model using a nonlinear model that considers the voltage dependency of the electrostatic capacity in this paper. After various simulations and comparison with experimental results, we confirmed the effectiveness of the proposed model.

著者

朴 炳植

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.123, no.7, pp.808-813, 2003-07-01

被引用文献数

7 1

---

A CO<SUB>2</SUB>-capturing NO<SUB>x</SUB>-free H<SUB>2</SUB>O turbine power generation system is proposed in which middle pressure steam produced in a thermal power plant is utilized to increase generated power when demand for electricity is large. The proposed system can capture all the generated CO<SUB>2</SUB> based on the oxygen combustion method and emits no NO<SUB>x</SUB>, so that it causes no urban and global environmental problems. A combined cycle power generation system with 200MW gas turbine power output is adopted as an example of a thermal power plant. It was assumed that 32 t/h of steam with 25kg/cm<SUP>2</SUP> pressure produced at waste heat recovery boiler was utilized in the proposed system.It has been shown through simulation study that increase of power output by 11.8MW or 4.51% of the rated output is possible with no efficiency decrease. The amount of CO<SUB>2</SUB> reduction is estimated to be 19600t/y.The unit cost of generated power is estimated to be 8.38yen/kWh, annual gross profit of the proposed system 271 million yen, depreciation year 4.87, and thus the proposed system is estimated to be economically feasible.

著者

吉野 純 北 裕幸 田中 英一 長谷川 淳 久保 宏 世永 茂

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.124, no.5, pp.723-732, 2004-05-01

被引用文献数

7 2

---

Recently, a number of electric consumers have concerned about the reliability of electricity to be served. For example, some consumers need the electricity with a higher reliability by the automation of manufacturing processes. On the other hand, some consumers need the electricity of a cheaper price even if the reliability becomes a little worse. Under such circumstances, it is necessary that power suppliers evaluate the needs of every consumers precisely and propose the most desirable measures for meeting their requirements. This paper develops a tool to analyze the reliability for high-voltage supplied consumers quantitatively. Further, this paper presents a method for evaluating the outage cost of consumers to help them choose the most appropriate measures for maintaining the reliability. The proposed method applies the fuzzy reasoning approach. The validity of the proposed method is ascertained through some numerical simulations.

著者

税所 真前 伊瀬 敏史 辻 毅一郎

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.123, no.8, pp.964-973, 2003-08-01

被引用文献数

19 14

---

In the large-scale factories like ironworks, many power electronic inverter loads exist, and these inverter loads are connected into ac systems by using rectifiers. On the other hand, DGs (Distributed Generators) such as photovoltaic generators and fuel cells, or ESSs (Energy Storage Systems) such as secondary batteries and SMESs (Superconducting Magnetic Energy Strages), which are dc power sources will be introduced to distribution systems more and more. These are connected into ac systems by using inverters. Therefore, it is expected that some countermeasures to achieve a dc distribution system which can reduce power losses due to rectifiers and inverters, should be developed.<BR>In this paper, a dc loop type distribution system is proposed as one of the new dc distribution system configurations. The calculation results of power losses for the dc loop type distribution system are compared with those for an ac distribution system. Moreover, this paper shows configurations and simulation results of the inverter, bi-directional rectifier and PFC (Power Factor Corrector) used in this system.

著者

西川 寛

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.127, no.7, pp.827-832, 2007-07-01

被引用文献数

2 2

---

Following the examples of other countries, in April 2005 Japan launched wholesale electric power exchange operations as a primary item of system reform in line with electric liberalization. Only two years have passed since the initiation of these operations. However, in the summer of 2005, the surge in market prices was evident, which suggested that certain measures should be taken to confront potential market risks. Establishing a useful system for forecasting market prices through the modeling of price fluctuations in the wholesale electric market became essential. Currently, various price models are being proposed. Taking both the limited amount of data and the model's purpose into consideration, this study adopted the univariate time series model.<br>We conducted a time series analysis on the open price indexes in the JEPX spot market with the Box-Jenkins method. Since a seven-day cycle can be observed in the data, we adopted the seasonal ARIMA model. In accordance with the procedures of the Box-Jenkins method, we determined the degree of the model's polynomial using the autocorrelation and partial autocorrelation of the data and estimated the parameters of the model with the maximum likelihood method. We conducted a forecast on next day JEPX spot market prices with this time series model and examined its validity and utility as a forecasting tool.<br>Price forecasts made with this model require only a small amount of data and will save substantial analysis work. Consequently, this method is expected to be widely used by market participants as the reference data for their bid pricing.

著者

本郷 保二 道下 幸志

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.12, pp.1535-1542, 2008-12-01

被引用文献数

6 1

---

The overvoltage associated with direct lightning hits has been the important factor for the insulation design of a distribution line. In this paper, the sparkover rate of a medium-voltage line associated with direct lightning hits is investigated based on numerical calculations obtained by using EMTP and statistical analysis by taking account of the correlation between the peak value and the front duration of return-stroke current waveform. When the line is equipped with surge arresters at the interval of 100m in addition to the overhead ground wire, the sparkover rate associated with subsequent strokes is higher than that associated with first strokes. This demonstrates the importance of the study of current parameters for subsequent strokes.