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
114 巻, 2 号
選択された号の論文の15件中1~15を表示しています
  • 加藤 厚
    1994 年 114 巻 2 号 p. 121-124
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
  • 岩坪 理恵子, 合原 一幸
    1994 年 114 巻 2 号 p. 125-129
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
  • 鈴木 浩
    1994 年 114 巻 2 号 p. 130
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
  • 川崎 憲介, 大西 徳生, 鈴木 茂行
    1994 年 114 巻 2 号 p. 131-136
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    In general, the photovoltic power generation systems may be interconnected with the distribution systems of public utility. The researches of photovoltaic sysem however have been limited to the photovolataic system itself and the partial influences to a distribution system when the photovoltaic systems are interconnected with it. But the influences on the whole power systems have not been researched yet.
    When the photovoltaic systems are distributed as dispersed generation systems, it is necessary to investigate the distributed insolation on the electric power service area for researching the influences of photovoltaic systems. Therefore we have approached to estimate area insulation distribution from the measured insolation data on the specific points. As the result, we have obtained a good prospect by this estimation approach.
  • 藤田 秀紀, 後藤 益雄, 鬼頭 幸生
    1994 年 114 巻 2 号 p. 137-144
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    Recently, with the growth of demand, power system becomes large and complex and generation plants are located far from the load center. As a result, power system instability becomes more serious.
    On the other hand, the active and reactive powers are controlled rapidly and flexibly by the superconducting magnetic energy storage (SMES) system.
    In this paper, we propose a practical method to suppress power oscillation in a multi-machine power system by using SMES, in which its active power is controlled by the signal derived from a bus frequency deviation. This controlled scheme is conducted easily only by detecting the frequency deviation on the site.
    The proposed method is examined on a 4-machine miniature power system connecting 1 MJ-SMES as well as another digital simulation using the same model.
    The result of this examination study shows the effectiveness of the proposed method.
  • 前田 龍己, 大西 徳生, 鈴木 茂行
    1994 年 114 巻 2 号 p. 145-151
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    Recently, according as electric power systems become very large and complicate, several phenomena of voltage collapse at the load end of power systems have been observed. So, the voltage stability problems of power systems have been closed up. There are many reports about the voltage instability phenomena that progress relativery fast. However, most of them are reported about the phenomena for normal cases of the balanced transmission line condition.
    In this paper, we describe the voltage stability of the power system from some experimental results. The influences of the load condition and the faults condition of the transmission line to the dynamic voltage stability and the progressive speed of unstable phenomena are discussed. We also inventigate the improvement of the voltage stability and the transient phenomena of the power system when the falut transmission line is closed with multiple reclosing system.
  • 金丸 公春, 豊田 重裕
    1994 年 114 巻 2 号 p. 152-160
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    Composite Fiber-optic overhead ground wires (OPGWs) have been installed to major power transmission lines. Using these OPGWs, maintenance information systems for power transmission lines have been devel-oped and put into practice. However, there still remain problems in data transmission scheme. The variety of information required for power line maintenance work includes data which practically allow rather slow transmission as well as data which require high speed transmission. It also includes data of both periodical and random initiation. Therefore, single data transmission method with single speed throughout the system will result in the deterioration of efficiency and economy. The authors investigated the features of various types of information required for power line maintenance, and studied the method of data transmission through the optical fibers within OPGWs. As a result, it was found that the hierarchy-type configuration which is composed of high-speed trunk line by cyclic data transmission and low-speed local line by random data transmission is effective for the sysems. This method has been applited to actual power lines. The practical performance is also discussed in this paper.
  • 千住 智信, 上里 勝実
    1994 年 114 巻 2 号 p. 161-166
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    The stabilizing facilities for power systems, such as series capacitor, system damping resistor, superconducting magnetic energy storage (SMES), phase shifter, etc., are used for improving the stability of synchronous generators. The control principle of these facilities to enhance the system damping is the same in the sense that these stabilizers control the active power so as to stabilize power systems. The generalized control method for these facilities has not been studied from the viewpoint of active power control.
    The generalized control method applying the variable structure control from the viewpoint of acceleration power for the synchronous generators is proposed in this paper. The variable structure control can be applied to both nonlinear and linear systems and has robustness for parameter variations.
    This paper, firstly, derives coutrol law in general form from the viewpoint of active power in the synchro-nous generator. This control law can take account of the automatic voltage regulator and governor effect indirectly. The feedback gains of the controller can be determined taking account of parameter variations in the synchronous generator. Secondly, this method is applied to the one-machine infinite bus system with a variable series inductance so as to investigate the validity of this control method. The simulation results show that the controller is able to improve the system damping of the power system and is especially profitable to parameter variations.
  • 政川 俊康, 小村 広司, 角田 孝典, 長岡 直人
    1994 年 114 巻 2 号 p. 167-172
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    An evaluation system or a transfer runcuon in rrequency aomam is aeveiopea in tms paper. i ne transre function of a two terminal-pair network is indispensable for estimating an input signal waveform from a give output. The transfer function is obtained by transforming the input and ouptut signals from time to frequent domain. To improve its numerical accuracy and stability, linear-approximated Laplace transform (LLT) applied.
    To express the transfer function by a rational function, a nonlinear-parameter estimation method proposed. The proposed method is stable by applying a direct search method. Also, a differential functioi which is indispensable for Newton-Raphson method, is unnecessary.
    A transfer function estimating system, which is composed of the frequency-time transformation and tr nonlinear parameter estimation, is developed. The system is more general than a conventional method whic is obtained from an equivalent circuit of a traget network.
    The proposed method is applied to an input wave estimation of a capacitive voltage transformer of whic the equivalent circuit is unknown. The result shows a good agreement with a field test result.
  • 甲斐 隆章, 舟橋 俊久, 佐々木 春生
    1994 年 114 巻 2 号 p. 173-178
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    Theoretical transient analysis of a synchronous machine short-circuit has been carried out by using two-reaction theory so far. However, the analysis becomes very complicated and it needs a detailed knowlege of synchronous machine.
    This paper proposes a new analytical method, by which the above analysis can be easily carried out, using symmetrical component method. The proposed analytical method has an assumption that the direct axis and the quadrature axis circuits of the machine are symmetrical. However, since large capacity synchronous generators of a power system are almost cylindrical rotor machine, the method is useful for the transient analysis of power system faults. The accuracy of the method is confirmed to be satisfactory in comparison with the calculations using EMTP.
  • 永田 武, 佐々木 博司, 北川 稔
    1994 年 114 巻 2 号 p. 179-185
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    When electricity supply is interrupted due to a fault, it is essential to restore promptly the power system according to an adequately planned restoration procedure. A problem of obtaining an appropriate target system for restoration is referred to as a power system restoration problem. The authors have already proposed a very efficient method based on the network simplex method which lies in the category of mathematical programming approaches. Althogh the method is effective to most of system conditions, it has turnd out that this method is likely to give undesirable result in case of abnormal network conditions.
    In this paper, the authors propose an effective and computationally fast solution algorithm based on the mixed integer programming approach, which can resolve the shortcoming of the former method. The solution speed is greatly improved by incorporating the restoration strategies of system operators. Assumptions postulated in this approach are: (1) 0-1 variables are allocated to branches and loads to present their status, (2) continuous variables are taken to represent barach flows, and (3) costs are assigned to branches to represent their priorities during restorative operations and power flow limits. The proposed approach can be used to complement the former approach.
    The new approach has been applied to restoration problems of practical size and simulation results demonstrate its advantage over the former method for intricate operating conditions.
  • 駒井 研二, 福井 伸太, 松本 啓之亮, 森寺 大輔, 小林 隆義
    1994 年 114 巻 2 号 p. 186-194
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    This paper describes a fault diagnostic system using a task-specific shell, MELDASH, and results that confirm its effectiveness. MELDASH (_??_itsubishi _??_ectric _??_iagnostic Application-specific expert system _??_ell) is a task-specific shell that reflects and makes use of the nature of model-based diagnosis. It is developed to overcome the drawbacks of methods that depend on operator knowledge. A high-performance fault diagnostic system is constructed simply by adding an application model to MELDASH. A prototype system is verified by connecting it to an operator training simulator. It is able to make a proper diagnosis in 79 difficult fault cases.
    Verification results shows that the prototype system has sufficient accuracy. We confirm the effectiveness of this fault diagnostic method for future energy management systems.
  • 道上 勉, 小柳 薫
    1994 年 114 巻 2 号 p. 195-204
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    To adjust a frequency during midnight or while an electric power system is carrying a light load, an AC excitation synchronous machine is recently being used in place of the conventional fixed-speed synchronous machine as the generator/motor at a pumped-storage power station. The use of this synchronous machine makes it possible to adjust the rotor speed and to use its inertial energy. We have prepared this paper to show how we can improve the power system stability by using the highly responsive control of the terminal voltage and the active electric power control through the AC excitation control of this adjustable-speed machine. The abstract of this paper can be summarized as follows:
    (1) We can enlarge the zone of stable operation by performing terminal voltage and active power control along with current control for the AC excitation of an adjustable-speed machine.
    (2) As the stability analysis model of an adjustable-speed machine, we can use an AC excitation woundrotor induction motor. We were able to verify the effectiveness by comparing simulations with the results of the transmission system simulator.
    (3) We can substantially improve the system stability by absorbing the power swing of the fixed-speed machine with the adjustable-speed machine, thereby decreasing it.
    (4) The effect produced by the adjustable-speed machine for the improvement of the power system stability is more prominent in the transient stability than in the dynamic stability and also more so in the pumping operation than in the generating operation.
  • Optimization involving general constraints
    Masakazu Kato
    1994 年 114 巻 2 号 p. 205-210
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    To achieve more economical and secure system operations short-term operational planning is very important. Although many methods focusing on unit commitment have been proposed, the resulting schedule is not always acceptable by system operators. This is because it does not consider all system operational constraints such as security in contingency cases, which are very difficult to represent and treat explicitly.
    This paper proposes an optimization method for short-term operational planning, considering such general constraints for secure system operations. This proposed optimization method employs a schedule modification and a search method which takes application domain heuristics into account.
    This method has proved to be practical and efficient from numerical simulations.
  • 松島 敏雄, 石塚 慎二
    1994 年 114 巻 2 号 p. 211-219
    発行日: 1994/02/20
    公開日: 2008/12/19
    ジャーナル フリー
    This paper shows an algorithm for prediction of remaining battery discharge time that can be applied to the lead-acid batteries installed in telecommunications power systems. In this method, the remaining battery discharge time can be predicted by deducting the integrated discharge electricity from the battery's available capacity, assuming battery is discharged according to the load current profile stored in memory. In this deduction, the amount of discharged electricity and the battery's available capacity are transformed into a value equivalent to the 10 hour-rated current discharge, using the coefficient clarified in this study. This prediction algorithm is examined by applying it to several load current profile and the results show the prediction accuracy to be within a range of 5%. The construction of this prediction equipment is also shown.
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