IEEJ Transactions on Power and Energy
Online ISSN : 1348-8147
Print ISSN : 0385-4213
ISSN-L : 0385-4213
Volume 113 , Issue 11
Showing 1-18 articles out of 18 articles from the selected issue
  • Jun Hasegawa, Hitoshi Okubo
    1993 Volume 113 Issue 11 Pages 1181-1185
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Download PDF (3570K)
  • Kosuke Kurokawa
    1993 Volume 113 Issue 11 Pages 1186-1189
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The author describes the overview of photovoltaic systems R & D efforts in Japna, including a basic scheme to reach the state of their realization, R & D items in the system technology, the new target settled by New Sunshine Project and technical problems to attain the target.
    Download PDF (911K)
  • Xifan Wang
    1993 Volume 113 Issue 11 Pages 1190-1193
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    China has a large population and a vast territory. She also possesses an abundant variety of natural resources. Recently rapid economic growth requires a faster development of the electric power industry in this country. This paper reviews the current status and long term development strategy of the electric power system in China. The key research topics in the power system field are also presented in the paper.
    Download PDF (808K)
  • Tadasu Takuma
    1993 Volume 113 Issue 11 Pages 1194-1198
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The paper first reviews the recent trends of research subjects in high voltage engineering, and explains several current topics now actively studied. They are concerning electric field calculation, laser induced lightning, high voltage testing, gas insulation, and so on. The paper also describes the author's view on the future in high voltage engineering.
    Download PDF (1101K)
  • Ja-Yoon Koo, Soon-Chui Hwang, Jin-Soon Park
    1993 Volume 113 Issue 11 Pages 1199-1202
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this report, we have presented some considerations on the high voltage extruded power cables installed in KOREA consisting of two parts.
    In the first part, we have dealt with some fundamental basic concept applied for our high voltage cables:
    -modeling on the forced cooling system
    -calculation of permissible current
    -some different aspects in operation between IEC and JCS
    In the second part, we have shown several technical informations concerning high voltage power cables fabricated and installed in KOREA:
    -design conception of XLPE cable joint
    -electrical stress for 154kV XLPE cable
    Download PDF (1047K)
  • Yasuhiro Hayashi, Shinichi Iwamoto
    1993 Volume 113 Issue 11 Pages 1203-1212
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In general, electric power companies must prepare power supply capability for maximum electric load demand, because it is very difficult to store electric power at present. It takes several years and requires a great amount of money to construct power generation and transmission facilities. Therefore, it is necessary to forecast long term load demand exactly in order to plan or operate power systems efficiently. Several methods have been investigated so far for the long term load forecasting. However, because the electric loads consist of many complex factors, good forecasting has been very difficult. In this paper, we propose a long term load forecasting method using a recurrent neural network (RNN). A recurrent neural network is a mutually connected network, and has an ability of learning patterns and past records. In general, when interpolation is used for unlearned data sets, the neural network gives reasonably good outputs. However, when extrapolation is used such as in the long term load forecasting, some kind of tunings have been necessary to obtain good results. Therefore, in order to solve the problem, we propose a method in which growth rates are used as input and output data. Using the proposed method, successful results have been obtained, and comparisons have been made with the conventional methods.
    Download PDF (2386K)
  • Yasumasa Fujii, Yoichi Kaya
    1993 Volume 113 Issue 11 Pages 1213-1222
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The purpose of this study is to make a comprehensive assessment of the measures for reducing CO2 emissions from future man's global energy system, and then to sketch concrete scenarios for its desirable development through the use of a global energy model. In the framework of the energy model built here, the whole world is geopolitically divided into ten regions so that it can explicitly evaluate the differences in regional economic and geological conditions. The model can assess the various technology options up to 2050 by optimizing the sum of the total energy system cost and the amount of the tax levied on CO2 emissions. As specific technology options, the model takes into account energy conservation in end-use and conversion sectors, utilization of various renewable energy resources, disposal and recycle of CO2 recovered, and innovative system technologies. The results of the study suggest that the CO2 problem can not be easily settled by any single technology option considered here. However, they also suggest that if those options are reasonably combined with one another, there exist great CO2 emission reduction potentials to stabilize annual global CO2 emissions over the first half of the next century at the present level.
    Download PDF (2616K)
  • Fuminobu Naito, Junichi Toyoda, Misao Jousho, Takashi Sato
    1993 Volume 113 Issue 11 Pages 1223-1230
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In a detailed dynamical analysis of SMES installed in power systems, it is important to coordinate the digital simulations for the slow dynamic model of multi synchronous machines and for the fast dynamic model of SMES in which the commutation characteristics in converter can be included.
    In this paper, a practical simulation method is developed for the aim to dual-time-scale modeling. Concurrent processes are built with parallel constructions of the phasor based numerical analysis for multi synchronous machines coupled through the network and the instantaneous voltage and current analysis for SMES and its converter system. The concurrent processes for a dual-time-scale simulation are realized by multi transputer network.
    Proposed simulation technique is successfully applied to verify the experimental results obtained by a 1 MJ-SMES test system which has been developed at Tohoku Electric Power Company in 1991.
    Download PDF (1052K)
  • Shigeo Hayashi, Takafumi Yoneda, Akira Kawata, Takeshi Nagasawa, Megum ...
    1993 Volume 113 Issue 11 Pages 1231-1238
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    It is important to include the behavior of load in studies of loss of generation and consequent load shedding and also in studies of long-term dynamics of a power system. This paper proposes a method which estimates load-frequency and load-voltage characteristic constants separately at the same time, by using normal operating data.
    The power system can be represented as an equivalent model which is composed of a major bus load, an equivalent impedance and a voltage source behind it. When the load capacity is small enough compared with the total system capacity, variations of active power of the load have little effect on frequency changes in the total system. Voltage changes behind the equivalent impedance are caused by variations of the operating condition in the external system, so voltage changes are independent to variations of active and reactive power of the major bus load under the state of nominal frequency and voltage. So coherences between them decreases to zero according to the increase of data in number and it is possible to estimate the load-frequency and load-voltage characteristic constants. Necessary measuring periods and accuracies of estimation are clarified and the effectiveness of the proposed method is verified by simulation results.
    Download PDF (1487K)
  • Suresh Chand Verma, Koichi Nakamura, Katsuhiko Naito, Mototaka Sone, H ...
    1993 Volume 113 Issue 11 Pages 1239-1248
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In this paper, an application of new computing hardware, i.e. Digital Signal Processor (DSP), known for its pipe line architecture, is considered for performing the load flow computations. The DSP is made operational with the help of memories and personal computer (PC) as its host, and this computing system is named as DSP system. The complete job of performing load flow computation is assigned to the DSP. To realize high computing power of the DSP system as well as to exploit the sparsity of power system, the band form of power system matrix is considered. For band transformation, a fast band ordering scheme is proposed. The validity of the proposed band ordering scheme and the speed-ups of the load flow computation with this band ordering in variable matrix setting are demonstrated using several test power systems.
    Download PDF (1583K)
  • Soji Kojima, Masahiro Kan, Shigeru Yokoyama, Tosiaki Ueda
    1993 Volume 113 Issue 11 Pages 1249-1255
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    A new evaluation method of backflashover due to lightning stroke was proposed taking induced voltage on an horizontal line caused by return stroke current corresponding to tower current into considerations, which is not evaluated in conventional study. The new method became possible by the approach that the analysis program of induced voltage by EMTP (Electro Magnetic Transients Program) was developed and it could be assembled in general circuit analysis.
    In the new method the terminal voltage of an horn gap of transmission line is tolerably higher than in conventional study because induced voltage on a line has reverse polarity compared with that of tower voltage by stroke and therefore those differential voltage is applied to an horn gap.
    Consequently, flashover of an horn gap is easy to occur not only in upper phase, but also in middle or lower phase and the response voltage of a substation is higher. Surge voltage wave in the new method agrees with that measured in field substation better than in conventional method.
    Download PDF (1289K)
  • Tsutomu Michigami
    1993 Volume 113 Issue 11 Pages 1256-1264
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The power supply system for a metropolitan area consists of multiple 275kV power cable systems to supply power to a large number of consumers. Each system has a large charging capacity (capacitive reactive power). When 275kV power cable systems have a voltage drop, their charging capacity decreases. However the reactive power losses, increase in the 275kV overhead transmission lines, which supply large power to power cable systems, thus causing the performance of the power supply system to deteriorate.
    In this paper, I report the following three points:
    (1) When the secondary power system of the trunk substation is a large-scale power cable system, new techniques can greatly improve to voltage and reactive power characteristics by controlling the rise of the sending end voltage at the secondary side of the trunk substations and maintaining the voltage of power cable systems at a constant level.
    (2) In the use of this control technique, it has been demonstrated that controlling by the direct-detecting method of a voltage drop in the primary power system is superior to one that controls by the indirect-detecting method, which increases load power in the cable system.
    (3) The results of simulations obtained by using a 275kV cable system model and a multima-chine power system model show that the use of this control technique can produce a good effect despite the allowances made for the opposite effect: a decrease in the capacity of power capacitors resulting from voltage drop at the tertiary voltage of a 500kV transformer.
    Download PDF (1595K)
  • Keiji Nakamura, Takamitsu Suzuki, Chobei Yamabe, Kenji Horii
    1993 Volume 113 Issue 11 Pages 1265-1273
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This study was carried out to examine the possibility of lightning control using a photoionized plasma produced by a UV laser without an optical air breakdown. As its fundamental experiment, the characteristics of a laser-triggered spark gap (LTSG) were examined, where a laser beam was not irradiated on the surface of the electrodes. In this experiment, the KrF excimer laser was much effective for increasing the plasma density ne and the reduction ratio p of 50% breakdown voltage against the self-breakdown voltage. The relation between ne and p was explained by the streamer theory, and the reduction ratio p was increased by generating a long and high density plasma parallel to the discharge axis. On the other hand, the abnormal discharge process in triggered lightning using a rocket was examined, and it was indicated that the most important condition to trigger a lightning discharge was the production of a plasma channel whose length was 200m and density was about 1019 m-3. It was suggested that such a plasma channel could be produced by a KrF excimer laser with an energy of only about 3.67 J.
    Download PDF (2176K)
  • Katsuyuki Tomiyama, Yosuke Nakanishi, Yasuo Tamura
    1993 Volume 113 Issue 11 Pages 1274-1282
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Auto-parametric resonance has not been detected nor observed in a real power system, probably because the problem-oriented instrumentation network is not available today. It has been confirmed by our research group from the viewpoint of theory, digital simulations, and artificial transmission system with rotating machines that the auto-parametric resonance may come out in a power system where certain types of resonance conditions are satisfied as when the initial transient impact such as line opening, generator tripping, and a line-to-ground fault has been applied.
    The objective of this paper is to confirm the auto-parametric resonance phenomena on a large-scale advanced-type power system simulator (APSA) which features various functions which are very close to those of a real power system, and to promote the instrumentation techniques needed to record and analyze such infrequent phenomena.
    Download PDF (1331K)
  • Yutaka Kohno, Yasuhiro Hayashi, Shinichi Iwamoto
    1993 Volume 113 Issue 11 Pages 1283-1291
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    When analyzing dynamical stability in power systems, there exist variable parameters, for example, variable gains and time constants of controllers in its system matrix. In the conventional representative techniques, we have to analyze all patterns of the system matrix one by one using Routh-Hurwitz method and so on, which is a difficult task. However, studies of the robust control theory such as Kharitonov theorem has been performed, recently. And some works have been published in the section of power systems. The Kharitonov theorem can distinguish stability of the characteristic polynomial whose coefficients have variable ranges independently. Therefore, we have to obtain the characteristic polynomial from the system matrix. However, in the conventional representative techniques, the transformation from the system matrix with variable parameters to the characteristic polynomial is very difficult, because the system matrix is generally huge in power systems. In this paper, we employ a simple way to do that transformation using Danilevski method. Furthermore, we apply the mapping theorem and the Kharitonov theorem to a one machine to infinite bus system which has variable parameters in its AVR and governor, and propose an efficient way to analyze using those theorems.
    Download PDF (1080K)
  • Hiroshi Inujima, Takeshi Masui, Hiroshi Maekawa
    1993 Volume 113 Issue 11 Pages 1292-1298
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Gas insulated switchgears (GIS) are important equipment in electric-supply stations for that advanced techniques for safety and maintenance are required. So, we started developing a system that can automatically monitor and diagnose a GIS in service. This article focuses on some problems concerning insulating functions of GIS to discuss a method of signal processing for partial discharge detection and position identification. For sensors, potential detectors were installed on flanges of the GIS. Focusing on the potential fluctuations measured by these detectors, we created an auto-regressive model for potential fluctuation in a state without any partial discharge. This model is called a normal state model. Difference was found between potential fluctuations measured during partial discharge and those of the normal state model. The index of whiteness test method of the residual random process is a useful parameter for representing this difference and we found that using this allowed detection of partial discharge that could not be found at normal potential levels. These results mean bright prospects for manufacturing a monitoring system that can detect deterioration in GIS insulation with a high sensitivity in an early stage and that also operates on-line.
    Download PDF (1528K)
  • Yasuyuki Tsutsumi, Takayuki Isizuka, Kun Ono, Manabu Takeuchi
    1993 Volume 113 Issue 11 Pages 1299-1305
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Early in operation of high current density, cathode potential of phosphoric acid fuel cell having well wet proofed catalyst layer is found to be unstable and to decrease rapidly at some operating conditions.
    Previous impregnation of phosphoric acid in the catalyst layer is useful for stable operations at high current density. When weakly wet proofed catalyst layer is used, this initial unstable behavior at high current density does not apear. At the operation of high oxygen concentration, the potential of the cathode is also stable.
    Operating temperature and the air flow rate are not effective on this initial unstable behavior. These decreased potential at initial operation recovers immediately after increasing oxygen concentration or decreasing current density. Decreased generating capability is held in nitrogen environment under open circuit potential until oxygen is supplied.
    Potential decrease corresponds to increase of oxygen gain, that is, increase of concentration polarization. Oxygen shortage in the catalyst is suggested as the cause of this unstable behavior.
    Download PDF (1249K)
  • Eiichi Segawa, Takeo Wakai, Tsutomu Sakai, Masaki Saiki, Tatsuo Kawamu ...
    1993 Volume 113 Issue 11 Pages 1306-1307
    Published: November 20, 1993
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Download PDF (1585K)
feedback
Top