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

門脇 昌紀

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.132, no.3, pp.NL3_3-NL3_4, 2012-03-01 (Released:2012-03-01)

参考文献数

3

著者

高橋 優大

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.133, no.3, pp.NL3_3-NL3_5, 2013-03-01 (Released:2013-03-01)

参考文献数

2

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

高野 富裕 松本 啓之亮 大木 功 大橋 敏明

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.115, no.7, pp.795-802, 1995-06-20 (Released:2008-12-19)

参考文献数

8

---

The authors have proposed a new framework of automatic knowledge acquision method and its prototype system has been reported at(6), which has generated switching sequences for substations. This paper will present its application to instruction table generation for local load dispatching offices. In the case of dispatching office the huge number and individual particularity are the points at issue. The office has to deal with hundreds of substations and transmission lines, and make a few hundreds of switching instruction tables a month. Generating tables is one of the most difficult tasks because the uniqueness of substations such as structural differences and particular management rules have prevented us from completing knowledge base which will contain thousands of rules. Our approach concerns the point for easy knowledge acquisition of the expert system, using an original learning algorithm named HCL (Hierarchical Concept based Learning). The HCL generates operational knowledge from cases in the past. This paper will discuss the fundamental problems of instruction table generation for dispatching offices and the solution to it by our approach. The method will be shown to construct and update its knowledge base automatically, using an actual network and operational cases of a dispatching office.

著者

犬飼 道彦 西田 正 野呂 純 松田 明洋

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.123, no.9, pp.1040-1046, 2003 (Released:2004-05-28)

参考文献数

3

---

This paper describes the advance of the ground relay of the line protection.First of all, we examined the ground fault in a resistively grounded power system. The protective relay detects the ground fault by the zero phase current in the system. There are two methods for the current input to the relay. One uses the residual circuit of CT secondary winding, and the other uses the CT tertiary winding. When the ground current is insufficient in the residual circuit, the CT tertiary winding is used. In order to omit the CT tertiary winding and to get more reliability, we reviewed the full-scale of relay and evaluating the error of CT. As result, almost all transmission lines could omit the CT tertiary winding.Next, we examined the ground fault with high fault resistance in a solidly grounded power system. When that fault occurs in the system, the PCM current differential relay acts by fault current. So, this relay possibly mal-operates when the CT secondary circuit is disconnected. Therefore, it uses a special CT to raise the reliability. Nowadays GIS has become small and the CT installation space has been decreased, it is needed to reduce these CT cores. In order to omit the special CT, we utilized the combination of the power relay and the rate of change of relay current. As a result, there is a prospect that the relay would not need the special CT.These improvements are effective to reduce cost too.

著者

金城 達人 千住 智信 上里 勝実 藤田 秀紀

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.124, no.8, pp.1059-1066, 2004 (Released:2004-11-01)

参考文献数

18

被引用文献数

5 8

---

The increased renewable energy utilization, especially photovoltaic panels using solar energy or wind turbine generators (WTGs) using wind energy, has been expected in recent years from view point of CO2 gas emission reduction and environmental conservation. However, the generated power is always fluctuating because the WTGs are driven by fluctuating wind. Therefore, an energy storage system should be installed to compensate these fluctuating elements. The energy capacitor system (ECS) which combined the electric double-layer capacitor (EDLC) and the electronic circuits are now under development. In this paper, control system configuration for active and reactive output power simultaneous control and the bi-directional inverter using current source EDLC are proposed. Moreover, we discusse control methods required in generating-power leveling for WTGs, and show the effectiveness of the proposed system through simulations.

著者

川﨑 章司 田岡 久雄 長尾 泰気 大中 奎佑

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.135, no.2, pp.89-96, 2015 (Released:2015-02-01)

参考文献数

28

被引用文献数

1

---

Renewable energy sources such as photovoltaic generation (PV) have been promoted to be innovated. However, the output of PV is influenced by the weather condition and cause a steep fluctuation. So it is important to forecast the output of PV when an electric power company makes the power supply schedule for demand. In this paper, the authors proposed a forecasting method for amount of insolation closely related to the output of PV. In the proposed method, the amount of insolation is forecasted through the application of Genetic Algorithm which is one of the optimization method by using the past measured data. In addition, the correlation coefficients are analyzed with the weather data and measured insolation data. And, the correlation coefficients are used as the weight of observe value. The authors verify the validity and prediction accuracy of the proposed method. Moreover, we tried to improve the forecasting error by using the latest measured weather data and weather data of the other point.

著者

山城 迪 木下 尚 仲村 宏一 木村 貢 福島 知之

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.115, no.12, pp.1426-1431, 1995-11-20 (Released:2008-12-19)

参考文献数

10

---

Under the current deregulation of electric utility industry, power system planning has become more complex. System planners are required to study how to use the available resources to meet customer's demand economically with an acceptable reliability and quality. The integrated resource planning is emerged as one of the effective approach for this problem recently and the approach has been expanded to include the value of reliability, that is, power interruption cost. This paper is aimed to develop a flexible decision method to select a favorable plan among various transmission system expansion alternatives, not only from power supplier's view point, but also from customer's perspective including cost of interruption. Bellman-Zadeh's maximizing decision using fuzzy decision set is applied as an flexible decision method which is able to reflect the planner's intensions. Numerical examples are shown to ascertain the effectiveness of the proposed method.

著者

石川 幸一郎 谷口 治人 鈴木 宏和 太田 豊 水野 陽二郎

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.7, pp.568-578, 2014 (Released:2014-07-01)

参考文献数

29

被引用文献数

6

---

Because of global warming, the attention to the photovoltaic generation has increased, and a lot of photovoltaic generations will be installed in the power system. In Japan, most photovoltaic generations will be connected to the distribution system. This will make the power flow in the power system changed. That is to say that the forward power flow (flow from higher voltage system to lower voltage system) reduces, or, moreover, that the reverse power flow occurs. Because of the change in power flow, the voltage characteristics will be also changed. Consequently, it is expected that the penetration of photovoltaic generation has some impacts on voltage stability. In previous study, the voltage characteristics in simple power system model which consists of one infinite bus, one load, and one photovoltaic generation is made clear. It is indicated from the results that there is not only forward power flow limit but also reverse power flow limit (left nose in PV curve), and that, when the output power from photovoltaic generation is very large, left nose sometimes has some impacts on voltage stability. In this paper, the voltage stability in the simple power system model considering the dynamics of an induction motor is discussed.

著者

石川 幸一郎 谷口 治人 鈴木 宏和 太田 豊 水野 陽二郎

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.1, pp.2-8, 2014-01-01 (Released:2014-01-01)

参考文献数

14

被引用文献数

2 9

---

Because of global warming, the attention to the photovoltaic generation has increased, and a lot of photovoltaic generations will be installed to the power system in future. In Japan, most photovoltaic generations will be connected to the distribution system. This will make the power flow in the power system changed. That is to say that the forward power flow (flow from higher voltage system to lower voltage system) reduces, or, moreover, that the reverse power flow occurs. Because of the change in power flow, the voltage characteristics will be also changed. Consequently, it is expected that the penetration of photovoltaic generation has some impacts on voltage stability. In this paper, simple power system model which consists of one infinite bus, one load, and one photovoltaic generation is considered, and the fundamental voltage characteristics are discussed by PV curves and phasor diagram. The voltage characteristics considering the current limit by PCS (Power Conditioning System) in the photovoltaic generation are also discussed.

著者

吉川 茂樹 北 裕幸 田中 英一 長谷川 淳

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.12, pp.1137-1145, 2005 (Released:2006-03-01)

参考文献数

23

被引用文献数

3 2 4

---

The authors have proposed the Flexible, Reliable and Intelligent ENergy Delivery System (FRIENDS) as a concept of future electric power systems. The concept of FRIENDS takes into account the deregulation of the electric power industry and progress of technologies such as power electronics, distributed generators (DG), distributed energy storage systems (ESS), information and communication. One of the most important characteristics of FRIENDS is that new facilities called Quality Control Centers (QCC) are installed between distribution systems and electric consumers.This paper presents a methodology for DSM based on a real-time pricing system through the information and communication network in FRIENDS. The economic use of DG and ESS in QCC is also considered in the proposed DSM. The sigmoid logistic function is used for modeling the real-time pricing system and a couple of parameters in the function are optimized by the Genetic Algorithm so that the profit of QCC is maximized. The effectiveness of the proposed DSM is ascertained by evaluating the profit or the load factor of QCC through simulations using model systems.

著者

久保 猛志

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.118, no.7-8, pp.750-753, 1998-07-01 (Released:2008-12-19)

参考文献数

2

著者

八木 幸弘 田中 秀郎 武藤 秀二 木村 人司

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.119, no.4, pp.438-444, 1999-04-01 (Released:2008-12-19)

参考文献数

11

被引用文献数

6

---

Degradation of XLPE cable by water trees gives rise to harmonics in the loss current. The authors are engaged in development of diagnostic methods for water tree degradation utilizing these harmonic components. As a result of this development, the following was discovered. The harmonic components occurring in the loss current provide an extremely good indication of the state of degradation. Harmonic components arise as a result of the nonlinear voltage-current characteristic of water trees. An equivalent circuit which incorporates this nonlinearity of water trees faithfully reproduces the loss current waveforms obtained in experiments. When a voltage at a frequency differing from commercial frequencies is superposed, a degradation signal occurs at a characteristic frequency.

著者

小宮山 涼一 柴田 紗英子 藤井 康正

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.133, no.3, pp.263-270, 2013-03-01 (Released:2013-03-01)

参考文献数

11

被引用文献数

2 9

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This paper evaluates optimal power generation mix considering massive deployment of variable renewable energy and regional power interchange. Japan has initiated feed-in-tariff (FIT) and expected significant introduction of PV and wind power for energy self-sufficiency and climate change. Wind power resource in Japan, however, concentrates mainly on Hokkaido and Tohoku region which is remote from electricity-consuming area such as Tokyo, and facilitating the considerable deployment of wind power requires the establishment of inter-regional power transmission line. On these backgrounds, we develop optimal power generation mix model including regional electricity exchange as large-scale linear programming model with 10 million variables and 30 million constraints. Calculated results show that regional grid expansion encourages wind power installation in Hokkaido and Tohoku region for supplying it to Tokyo area where PV power and stationary battery are alternatively replaced. The grid expansion, as well, promotes the shift of PV installation to Kyushu and Shikoku region which have longer sunshine duration, and interchangeably mitigates PV deployment in other regions through the transport of PV power from those two regions.

著者

久保 佑太 長岡 直人 馬場 吉弘 雨谷 昭弘

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.134, no.2, pp.99-106, 2014-02-01 (Released:2014-02-01)

参考文献数

13

被引用文献数

1

---

A reduction method of a lightning overvoltage on a Power Conditioning System (PCS) is investigated in this paper. The capacitors installed between the circuit and grounding terminal in the PCS determine the response against a first transient. The inductances, winding capacitances and excitation losses of the coils for the filter in the PCS should be also considered for estimating the overvoltage to ground at an input terminal of the PCS. The dominant factors of the maximum overvoltage are a grounding resistance, capacitances between a frame and output terminal of a solar panel and those between the PCS and ground. The overvoltage is decreased with decreasing the grounding resistance of the structure for the solar panels. The grounding resistance of the PCS has a minor effect on the overvoltage. The overvoltage can be reduced when a common grounding method is applied. A length of a cable between the output terminal of the solar panel and the input terminal of the PCS should be as short as possible.

著者

吉岡 芳夫

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) (ISSN:03854213)

巻号頁・発行日

vol.126, no.7, pp.653-656, 2006 (Released:2006-10-01)

被引用文献数

2 8

---

Gas circuit breaker and vacuum circuit breaker are the 2 main types of circuit breaker used in extra high voltage and medium voltage networks. After reviewing the history of these circuit breakers, their present status and technologies are described. As for future technology, computation of interrupting phenomena, SF6 gas less apparatus and expectation of the high voltage vacuum circuit breaker are discussed.

著者

周 卓敏 前田 哲彦 石田 政義

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.133, no.1, pp.19-25, 2013-01-01 (Released:2013-01-01)

参考文献数

23

被引用文献数

2 5 1

---

This paper presents capacity planning and economical evaluation of a renewable power system proposed for Okushiri Island, which is a remote island in the southwest of Hokkaido. In this system, the power demand is mainly provided by photovoltaic, wind turbine. Batteries are used as short time energy storage, and a hydrogen storage system (composed of water electrolyzer, hydrogen storage, and fuel cell) is used as long time energy storage. Optimal capacities of these power sources are those meet the required supply reliability, with the lowest cost. As the first step in the capacity planning, mathematical models for characterizing components are explained. The second step is to optimize the capacities of components. The configurations, which meet the required supply reliability with the lowest cost, give the optimal choices. These calculations are carried out with hourly meteorological data and energy demand data of Okushiri Island. As a result, hybrid storage (battery and hydrogen) is the best choice for Okushiri Island when high supply reliability is required. In the range of loss of power supply probability 0.1 to 0, the levelized cost of energy will be about 70-150yen/kWh.