電気学会論文誌B(電力・エネルギー部門誌)
Online ISSN : 1348-8147
Print ISSN : 0385-4213
ISSN-L : 0385-4213
136 巻, 7 号
選択された号の論文の20件中1~20を表示しています
解説
  • 植田 玄洋
    2016 年 136 巻 7 号 p. 617-620
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    To lower the lightning impulse withstand voltage of electric power equipment while maintaining the high reliability of its insulation performance, it is important to define in an organized way the insulation characteristics for non-standard lightning impulse waveforms that represent actual surge waveforms in the field and compare them with the characteristics for the standard lightning impulse waveform quantitatively. This paper introduces the method using overvoltage duration for converting non-standard lightning impulse waveforms into standard lighting impulse waveforms equivalent in terms of insulation intensity.
論文
  • 髙橋 明子, 山形 彰宏, 今井 純, 舩曳 繁之
    2016 年 136 巻 7 号 p. 621-627
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    This paper discusses chaotic properties of fluctuating photovoltaic generation (PV) power and reveals that PV power can be decomposed into a chaotic component having shorter periods and a long-term fluctuation component. The first step is to decompose the PV power into three components containing a long-term fluctuation component, a load frequency control (LFC) component and an irregular fluctuation component from normalized PV power data by using periodic regression analysis. The second step is to analyze the long-term fluctuation component and the LFC component using autocorrelation function. The third step is to clarify the chaotic properties of the LFC component using Lyapunov spectrum analysis. Finally, the simulation of predicting the LFC component and the normalized PV power data is carried out. This simulation clarifies that the LFC component has chaotic properties.
  • 大城 諒士, 原田 繁実, 金子 英治
    2016 年 136 巻 7 号 p. 628-635
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    Household appliances and information equipment with electrical circuits have come into wide use. These appliances and equipment seem sensitive to an electrical surge. In addition, a lightning might affect electrical systems not only on the lightning point but also on the systems at vicinity of the point. If the induced surges invade into low voltage distribution systems, it might cause severe damages to the appliances and the equipment. Therefore, it is necessary to investigate these induced phenomena. FDTD (Finite Difference Time Domain) method is often applied to analyze surge phenomena, which can treat analysis objects as three-dimensional circuits. For simulating these phenomena, we adopt VSTL rev. (Virtual Surge Test Lab. rev.) which is the surge analysis simulation program based on the FDTD method. In this paper, we discuss the investigation results regarding the lightning induced surge phenomena on low voltage distribution lines in a house and the relationship between lightning surges and a soil resistivity, and the effect on the surge phenomena by SPD (Surge Protective Device) on the low voltage distribution lines.
  • 乾 義尚, 坂本 眞一, 田中 正志
    2016 年 136 巻 7 号 p. 636-644
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    Detailed information on degradation process of lithium-ion batteries is essential to manage the batteries throughout their lifetime because degradation of the batteries associated with long-term usage is inevitable. To evaluate degradation degree of the batteries in detail, it is necessary to separately make clear the decrease in output power due to the increase in AC impedance and the decrease in battery capacity caused by the decrease in electromotive force. In this study, therefore, the authors at first propose a new evaluation method of detailed degradation process of lithium-ion batteries through measurements of AC impedance and electromotive force of degraded batteries. It is made clear that this proposed evaluation method can provide simple but detailed diagnosis of battery degradation degree, indicating usefulness of the proposed method. Next, as a first step for performance simulation of degraded lithium-ion batteries, the authors make clear that the already developed simulation method of battery transient voltage response, validity of which has been confirmed only for new batteries, is also applicable to degraded batteries.
  • ―詳細診断における軽微な巻線異常判定―
    宮嵜 悟, 水谷 嘉伸, 田口 彰, 村上 純一, 辻 直一, 高島 雅弘, 加藤 理
    2016 年 136 巻 7 号 p. 645-653
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    Frequency Response Analysis (FRA) is a powerful technique to detect internal abnormalities within power transformers. However, diagnosis criteria of power transformers by FRA have not been fully established yet. In this paper, a new evaluation method of degree of identification between two transfer functions is proposed. In the proposed method, a frequency window is employed and Cross Correlation Coefficient (CCF) is calculated with moving the window. Furthermore, the proposed method is applied to transfer functions of real transformers with or without some abnormalities. Based on this discussion, objective criteria for diagnosis of abnormalities of transformer windings by FRA is proposed. The proposed criteria are based on a few data of transformers with some abnormalities. Therefore the proposed criteria are tentative and they would be improved by accumulation of further data.
  • ―応急診断における巻線短絡・巻線変形の判定―
    宮嵜 悟, 水谷 嘉伸, 田口 彰, 村上 純一, 辻 直一, 高島 雅弘, 加藤 理
    2016 年 136 巻 7 号 p. 654-662
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    Soundness confirmation of internal windings of power transformers is important for reliable operation. In urgent situations such as invasions of lightning surge and external short-circuit faults, it is important to diagnose turns short and/or deformation of winding. In this paper, criteria in diagnosing turn shorts or heavy deformations of transformer windings using Frequency Response Analysis (FRA) are proposed. In FRA, measured transfer functions are compared with past measured data in principle. However, past measured data are not necessary in proposed diagnosis criteria. Therefore, proposed criteria are useful in soundness confirmation of transformer winding in the urgent situation.
  • 裵 辰玟, 西川 省吾
    2016 年 136 巻 7 号 p. 663-676
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    The purpose of this research is to develop a high performance and economical research of an accurate design technique of a linear generator of direct converting type of a small wave power generation system. And we study permanent magnet linear generator type as a wave power generation system because this type is direct energy conversion and has a higher efficiency than the existing system which uses a turbine and the aim is to verify the design method using the finite element analysis techniques. The reason basically is previous studies of small linear generators of conventional direct conversion scheme does not have consistent detailed design techniques, therefore the subsequent studies have been difficult. In particular, the study of the slot structure and leakage inductance of the linear generator proves to be difficult. In addition to this, the output equation is also not clear as the output characteristics of the conventional small linear generator had been verified using a simple constant-velocity movement, the verification method output characteristics of the conventional small linear generator had also been using a simple constant-velocity movement experiments, therefore the validity of the verification of the maximum output is not clear. So, we have constructed the detailed design technique to reproduce the sinusoidal velocity motion of the sea wave, and we verified the maximum output power. We have verified these findings by applying the finite element analysis techniques to reproduce the sinusoidal velocity motion of the sea wave. In this paper, we show their results.
  • 岩田 幹正, 大高 聡也, 合田 豊, 種﨑 征利, 濵川 智仁, 上村 健太郎
    2016 年 136 巻 7 号 p. 677-684
    発行日: 2016/07/01
    公開日: 2016/07/01
    ジャーナル フリー
    On a 66kV overhead transmission line equipped with the arcing horns interrupting the single-line-to-ground fault current (AHIFC), a two-phase short-circuit fault between an upper and a lower line caused by a lightning strike turned into a three-phase short-circuit fault. The authors have investigated the mechanism of the fault experimentally and clarified that the arc jets spouted upwards from the arcing horns of the lower line and the arc showed a tendency of rising easily due to the arc jets, then those caused the breakdown between the lower and the middle line, and the phase-to-phase short-circuit fault (PPSCF) occurred. In this paper, the authors investigated the PPSCF for the bird-damage prevention arcing horns which were installed in 66kV overhead transmission lines. As a result, the PPSCF tended to occur as the arc current increased and the upward wind velocity increased, which were different quantitatively from, but were similar as the results for the AHIFC. Considering the breakdown phenomena between the lower and the middle line, the investigations were carried out on the form of arcing horns for preventing the PPSCF. It was clarified that the PPSCF could be prevented by decreasing the upward angle and increasing the outward angle away from the steel tower of the both arcing horns on line side and steel tower side in order to move the arc jets spouting from the arcing horns and the hot gases generated by the arc jets in a horizontal direction.
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