IEEJ Transactions on Power and Energy
Online ISSN : 1348-8147
Print ISSN : 0385-4213
ISSN-L : 0385-4213
Volume 120 , Issue 11
Showing 1-23 articles out of 23 articles from the selected issue
  • Yasuo Sekii
    2000 Volume 120 Issue 11 Pages 1361
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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  • Takahisa Imajo
    2000 Volume 120 Issue 11 Pages 1362-1365
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
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  • Hiroyuki Miyata, Tohru Nakatsuka, Tohru Takahashi, Kumiko Kunii, Tsuyo ...
    2000 Volume 120 Issue 11 Pages 1366-1374
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In order to grasp the degree of harmfulness for conductive contaminants in HVDC polymer cable quantitatively, DC treeing breakdown characteristics of modified HDPE (polymer for HVDC cable) was examined using needle-plane electrodes.
    Treeing breakdown voltages become smaller in order of “DC>Imp.>DC+Imp. (reverse polarity)_??_DC polarity reversal”, and the scattering of breakdown voltage becomes smaller also in this order. This order agrees with the space charge effect near the needle tip (field relief by homo space charge-field enhancement by hetero space charge). The fact that needle tip radius dependence of treeing breakdown voltage has not been observed until 20-40 μm seems to indicate that a critical range of strong field is necessary for the growth of electron avalanche before tree generation, except the space charge effect. The divergent electric field has the most remarkable influence on the case of DC and DC polarity reversal because of the largest space charge formation. For instance, the breakdown voltage ratio of DC/DC polarity reversal as well as the drop in V-N characteristics of DC polarity reversal are much larger in divergent field (needle-plane sample) than those in uniform field (sheet or cable sample). Consequently, DC polarity reversal seems to require the most severest (smallest) conductive contaminant size in HVDC polymer cable.
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  • Ryuichi Ishino, Tomomi Ishikawa
    2000 Volume 120 Issue 11 Pages 1375-1381
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We have developed anew method which can measure movement of overhead power lines in the wind. This method uses images from an ITV camera system. The sway of the power line is videotaped and analyzed. Its measured frequency response to wind is compared to atheoretical model. It is found that the newmethod yield results which are in good agreement with the result obtained from the theoretical model for frequency response less than 0.5 Hz. And, by the result of frequency response, we can calculate sway mode of the power line in the wind. Our method also offers displacement of the sway of cable. We compared our method to the laser measurement. The difference between them was about 10cm at 255m away from the camera.
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  • Katsumi Uchida, Yoichi Kato, Masahiko Nakade, Daisuke Inoue, Hiroyuki ...
    2000 Volume 120 Issue 11 Pages 1382-1389
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Authors have developed a new life estimation method for water treed 22-77 kV XLPE cables based on a very low frequency (VLF) voltage withstand test. Breakdown tests under ac and VLF were carried out, using model cables and service aged XLPE cables. Based on the breakdown tests, we calculated optimal test voltage for remaining life estimation. Recently, we had on-site testing.
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  • Yuichi Maekawa, Chizuo Watanabe, Mitsumasa Asano, Satoru Maruyama, Tos ...
    2000 Volume 120 Issue 11 Pages 1390-1398
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper describes the development of XLPE cable for HVDC transmission. We have developed the insulating material, which has high resistivity and little space charge accumulations, for DC XLPE cables.
    The characteristics of breakdown strength and space charge accumulation were evaluated. As the results, it was found that model cables using new DC XLPE materials have good properties.
    The +/-500 kV DC XLPE cables and factory joints were designed and have been manufactured. And they have been subjected to short-term electrical test and mechanical test. As the results, it was found that the developed DC +/-500 kV XLPE cable was satisfied with required insulating properties.
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  • Yuichi Maekawa, Chizuo Watanabe, Mitsumasa Asano, Kazuo Watanabe, Mana ...
    2000 Volume 120 Issue 11 Pages 1399-1407
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We have worked on developing 500 kV DC XLPE cable.
    The first time, the space charge profile was measured using model cables insulated with the improved inorganic filler-added XLPE (SXL-A). Results showed that SXL-A could sufficiently suppress space chargeunder DC voltage.
    So, full-size 500 kV DC SXL-A cables with an insulation thickness of 23mm and associated factory joints were manufactured and initial electrical performance test were carried out. It was confirmed that they had sufficient initial electrical performance to satisfy the requirements for 500 kV DC XLPE cable.
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  • Hiroaki Suzuki, Shozo Kobayashi, Tsutomu Ono, Daisuke Muto, Hiroaki Ku ...
    2000 Volume 120 Issue 11 Pages 1408-1415
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    One piece, pre-molded joints have been used all over the world for high voltage (HV) XLPE cables, For those pre-molded joints, ethylene-propylene rubber has mainly been applied for many years.
    We have succeeded to apply a new cold-shrink technology on those pre-molded joints with silicone rubber which has lower elasticity, better mechanical properties, such as lower permanent set. With cold-shrink technology, pre-molded sleeves can be shipped expanded onto the carrier pipes. So the customer needs no tools for assembly on the jointing site and just needs to pull out the carrier pipes.
    All the type tests required on IEC standards 60840 were carried out including water immersion and heating cycle tests on our newly developed 110-138 kV cold-shrinkable joints (CSJ) and have shown good performance in all the tests, which means we became the first manufacturer all over the world who developed cold-shrinkable joints (CSJ) with silicone rubber for HV XLPE cables.
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  • Hiroshi Inuzuka, Tsuyoshi Inoue, Masaki Nakayama, Takaie Matsumoto
    2000 Volume 120 Issue 11 Pages 1416-1423
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    In a fault location system by the current surge detection, the difference time of arrival on the fault current surge is measured at two positions on either side of the fault point. However, a rounding of the wave caused by a frequency characteristic of the power cable degrades the accuracy of the fault location. To improve the accuracy, we use some signal processing method, a frequency compensation, a decision algorithm of a pulse arrival timing form the rounded pulse, and estimation of the surge velocity in the power cable with high accuracy. In the frequency compensation, a digital filter with the inverse of frequency characteristics of this power cable is designed. The rounded surge at the measured point is sharpened by this inverse filter. The velocity of the surge in the power cable is estimated from the measurement of the phase characteristics of the cable. The velocity estimated as mean value of the phase characteristics slope weighted by the frequency spectrum of the surge.
    A 1/10 scaled model of 275 kV cross bonded cable system was built for the test of real time fault location system. The relative location errors defined by the ratio of error distance and the location base length are measured at seven artificial fault points, and results of the accuracy estimated from each algorithms. As a result of signal processing the accuracy of the fault location had been improved with the location error within 0.5%.
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  • Hiroshi Inuzuka, Hidenori Inada
    2000 Volume 120 Issue 11 Pages 1424-1430
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    We have developed a new method to measure an attenuation characteristic of a power cable in high frequency range. The method numerically obtains an attenuation characteristic by suppressing an influence of reflections caused by impedance mismatching. The correction equations are derived from the relation of forward waves and backward waves with multiple reflections in the cable.
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  • Ampol Tbngkanawanich, Zen-Ichiro Kawasaki, Kenji Matsuura
    2000 Volume 120 Issue 11 Pages 1431-1436
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper presents a new system designed for locating multiple sources of partial discharge. The system employs a sequential triggering method which can detect many pulses or pulse-train electromagnetic waves emitted from partial discharge in one measurement. We utilize four VHF wideband antennas as electromagnetic sensors and calculate the time delay of arrival between them in order to locate PD sources in 3-D. With this technique, we can locate multiple sources based on the assumption that there is only one electromagnetic pulse contained in the detected time window of 2 μs or each time window indicates a signal from one source. The smoothed coherence transform is applied to improve the time delay estimation and compared with the standard cross correlation. The proposed system also enhances the reliability of the method because many pulses are analyzed. A field experiment was performed to evaluate the proposed system.
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  • Takeshi Ikeda, Tetsuya Ashida, Katsutoshi Kawasaki
    2000 Volume 120 Issue 11 Pages 1437-1442
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Many kinds of low voltage cable have been used in various plants, and have important roles upon the stable operation of all facilities. However, there was no effective method to diagnose the degradation of low voltage cables non-destructively until now, because almost all low voltage cables have no electromagnetic shielding layer and it is very hard to diagnose each cable by the megger test with service interruption. Mitsubishi Cable Industries has established the ultrasonic degradation diagnose method, and has developed an ultrasonic degradation tester, which easily and non-destructively diagnose the degradation of low voltage cables using the ultrasonic waves without any service interruption. In this method, the propagation properties of the ultrasonic waves in the surface layer of the cable sheath are measured and converted into the breaking elongation as an index of degradation. By using the ultrasonic degradation tester for regular inspections of low voltage cables instead of the megger test, degree of degradation, the harshness of the surrounding environment and the time to change the cables can be estimated easily and quickly, and total costs for the maintenance of low voltage cables were significantly suppressed.
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  • Shoichi Honjo, Hideo Ishii, Yoshibumi Sato, Hiroshi Hashimoto, Takashi ...
    2000 Volume 120 Issue 11 Pages 1443-1450
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Underground power transmission cables are mainly used in populated cities. They will become more popular in order to cope with the continuous increase in power demand. As underground space is already dense with facilities, it will be even more difficult to construct new tunnels for power cables. To make cables more compact is one of the important theme in cable technology. High temperature superconducting (HTS) materials have a potential to realize compact and high-capacity underground power cables because of their high critical current density, which is more than 1, 000 times larger than the operating current density of conventional power equipment. Since HTS power cables require liquid nitrogen cooling system, it is important to understand AC loss characteristics and to reduce the loss produced by FITS materials carrying alternative current.
    High temperature superconductors have I-V characteristics well represented by a power law. Such non-linear characteristics as well as complicated conductor structures make it difficult to estimate AC losses by theoretical approaches. Numerical methods are promising for quantitative analysis of the problem. We have already developed a new algorithm to deal with superconductors having power law I-V characteristics using finite element method. Using this code, we analyzed current distribution and AC loss characteristics of a transposed HTS cable conductor consisting of round wires, and discussed the effect of their transposition.
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  • Ryoichi Hara, Hiroyuki Kita, Eiichi Tanaka, Jun Hasegawa
    2000 Volume 120 Issue 11 Pages 1451-1458
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Recently the world wide deregulation trend of the electric power industry is progressing. In the deregulated power systems, it is expected that a lot of dispersed-type generation facilities and energy storage systems will be installed at the end point of the power system. Further, it is also expected that the consumer's requirements for the price, the reliability or the power quality will also become more diverse by this trend. Therefore, the future power system must change dramatically in order to cope with these various requirements.
    By the above background, the authors have proposed Flexible Reliable and Intelligent Electrical eNergy Delivery Systems, FRIENDS as one of the future electric power distribution system. In order to realize FRIENDS, it is indispensable to design the concrete interior structure of the key facility called Quality Control Center. This paper proposes the interior structure and the operation scheme of Quality Control Center from the viewpoint of the customized power quality service which is one of the most important objectives of FRIENDS. This paper also confirms the validity of the proposed structure and the operation scheme through momentary analysis using PSCAD/EMTDC.
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  • Naoki Itamoto, Seiichi Shimada, Kazuo Nakata, Hideki Motoyama, Masaru ...
    2000 Volume 120 Issue 11 Pages 1459-1465
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Observation of winter lightning has been carried out on a test transmission line since 1987. For the analysis of the observation results by EMTP, it is necessary to make parameters of the transmission line model clear. So we measured the lightning surge response characteristics on a tower of the test transmission line. The measured surge impedance for the transmission tower was 90 Ω and effective propagation velocity inside the transmission tower is almost 90% of the speed of light. We estimated influence of the arrangement of the current lead wire and the auxiliary potential wire, and analyzed the measured waveforms by EMTR The appropriate surge impedance at each section of the multistory tower model determined through EMTP analysis was approximately 80 Ω.
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  • Issei Takahashi, Hiroyuki Kita, Nobuyuki Yamaguchi, Ken-ichi Nishiya, ...
    2000 Volume 120 Issue 11 Pages 1466-1473
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    By a trend of recent worldwide deregulation, the electric power systems in Japan is approaching towards the open transmission access. Currently retail wheeling regulations are discussed in legislation for the future electric power systems operation. In a case that the retail wheeling regulations are introduced, it is necessary to evaluate the influence on power system operation rightfully and guarantee equity and transparency in the charges imposed on users of transmission facilities. When the retail wheelings are added in the power system with FACTS devices, it is necessary to allocate costs of FACTS devices among each retail wheeling depending on degree of their influences on power system operator.
    This paper presents an index that what degree some FACTS devices are responsible for congestion relief. And, Its index is allocated according to the retail wheelings' influences for congestion. Also, this paper verifies the validity of the proposed index using IEEE 14 system.
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  • Adi Soeprijanto, Naoto Yorino, Hiroshi Sasaki
    2000 Volume 120 Issue 11 Pages 1474-1480
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes an effective method for designing coordinated H∞ PSS's to improve the damping of local and interarea oscillations. Target modes, types of inputs of the PSS, and effective locations for each controller are examined using the participation factor and residue concept. To realize coordination of the controllers, a method for constructing the reduced model effective for this design is presented, minimizing the uncertainty for each controller. With such a small uncertainty, a tight design which yields marginal robustness can be realized, increasing the performance of each controller as well as that of the total system. The influence of the reduced model on the controller characteristics is discussed. The effectiveness of the proposed control design is demonstrated through nonlinear numerical simulations in a five-machine seven-bus system under two critical operating conditions.
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  • Naoto Yorino, Shigemi Harada, Satoshi Shioya, Hiroshi Sasaki
    2000 Volume 120 Issue 11 Pages 1481-1487
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper proposes a fast computation method to assess the voltage stability of a power system for branch outage contingencies. The load power margins with respect to saddle node bifurcations under faulted conditions are efficiently estimated. Nonlinearities of the power flow equations are partially taken into account to considerably improve the accuracy of stability assessment. Numerical examinations in IEEE 14, 30 and 57 bus systems show that, even in such small systems where the effects of single line outage is much larger than those of large systems, maximum error was 10%. The computation time of the method amounts to α+Kβ, where α is the computation time for the saddle node bifrucations and for LU factorization of the power flow Jacobian, β is almost equivalent to that of the forward and backward substitutions for the factorized Jacobian, and K is the number of branch outage contingencies.
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  • Geerli, Ryuichi Yokoyama, Luonan Chen
    2000 Volume 120 Issue 11 Pages 1488-1495
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Rapid move to a market-based electric power industry will significantly alter the structure of electricity pricing and system operation, In this paper, we consider a negotiation game of electric utilities, IPPs and large-scale customers as players in electricity market. The two-level game strategies are adopted to analyze the negotiation process among utilities, IPPs and customers since recognized as a rational decision for competitive markets, where utilities, IPPs and customers intend to maximize their own profits. The derived operation rules reflecting the competition can be viewed as an extension of the conventional equal incremental cost method for the deregulated power system. The proposed approach has been applied to several systems to verify its effectiveness.
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  • Pyong Sik Pak, Takanobu Kosugi
    2000 Volume 120 Issue 11 Pages 1496-1503
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper describes the evaluation results of CO2-capturing power generation systems which use solar thermal energy and gasified coal as the input energy. The following two power generation systems have been proposed and evaluated from the characteristic and economic points of view: a CO2-capturing hybrid power generation system (proposed system I), and a CO2-capturing three-stage heat-utilizing power generation system (proposed system II). In evaluation, a conventional integrated coal-gasification combined cycle power generation system (IGCC system) is adopted as the reference system. The proposed systems are assumed to be constructed in Albuquerque, U. S. and Osaka, Japan. The net coal-to-electricity efficiency has been estimated to be 51.0 % for the proposed system I, and to be 40.1 % for the proposed system II on higher heating value basis, whereas the efficiency of the conventional system is estimated to decrease from 43.7 % to 32.7 % when the CO2 generated is captured. Taking the IGCC system without CO2 capture as the reference system, the cost of CO2 emission reduction of the proposed systems I and II in Albuquerque are estimated to be 22, 100-23, 800 yen/t-C and 21, 800-23, 000 yen/t-C, respectively, and that in Osaka to be 37, 000-38, 700 yen/t-C and 23, 300-24, 500 yen/t-C, respectively. It has been shown that these are lower than the cost of CO2 emission reduction of the IGCC system with CO2 capture by 43, 800-48.400 ven/t-C.
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  • Hideyuki Ohno, Hiroshi Ito, Tomio Tange, Katsuhiko Naito, Yasunobu Yok ...
    2000 Volume 120 Issue 11 Pages 1504-1512
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    Experimental investigation was performed on an electromagnetically driven arc burning between the edges of parallel flat electrodes in atmospheric pressure. A pair of parallel flat electrodes having a length of 640mm, a width of 20mm and a thickness of 1.2mm is set up horizontally with a gap length of 13mm. After new electrodes were arranged, the arc was sequentially ignited either 100 or 200 times in interval of 30 seconds. The result revealed that after reaching the local maximum at iteration number Ntest of 10-15, the travelling velocity of the arc slightly decreased with an increase in Ntest for all of the d. c. arc current la in the range from 36.5 to 117 A. The skipping number Nskip of an anode spot per unit length proved to lessen gradually with Ntest for Ia=36.5 and 48 A and to remain constant for Ia=65, 90 and 117 A. For instance, Nsiap decreased from 102 to 80 m-1 with increasing Ntest from 10 to 100 times for Ia=36.5 A, while Nsbp was kept at 36 m-1 for Ia=117 A. Accumulated amounts Ma of the anode erosion and Mc of the cathode erosion, respectively, were found to rise almost proportionally with Ntest for all of Ia and to reach 118 and 65 mg at Ntest of 200 times in case of Ia=117 A, respectively.
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  • Hiroyuki Amano, Hideyuki Kameda, Haruhito Taniguchi, Susumu Maeda, Ter ...
    2000 Volume 120 Issue 11 Pages 1513-1520
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    This paper describes the equivalent circuit considering damper shield characteristics and the practical identification method of the parameters of a slow-response type superconducting generator. It can be seen that the proposed equivalent circuit model has high accuracy for variations of field current and armature current by comparing with testing results. This model enables us to analyze the improvement of stability for introducing superconducting generators appropriately.
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  • Yoshitaka Inui, Tomohiro Hirata, Motoo Ishikawa
    2000 Volume 120 Issue 11 Pages 1521-1528
    Published: November 01, 2000
    Released: December 19, 2008
    JOURNALS FREE ACCESS
    The authors have carried out γ-z two-dimensional time-dependent numerical simulations for a large-scale supersonic nonequilibrium disk MHD generator with two-divided anodes to make clear the ionization process in the nozzle with this type of anode and also to investigate the effects of the external and the leakage resistance between the two anodes. A generator with 100 MW thermal input using cesium-seeded helium plasma is analyzed. It is found that the two-divided anodes have excellent performance and the working plasma is effectively heated up to the fully-ionized seed condition between the two anodes in the nozzle. The existence of local high Hall electric field between the two anodes is essential for the ionization. The external resistance promotes the ionization but causes the stagnation pressure loss in the nozzle. The electric insulation on the insulator wall between the two anodes should be highly maintained because bad influence of the leakage resistance between them on the generator performance is much larger than it in the generation channel.
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