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Hashimoto T.,Hokuriku Electrical Power Company | Torii K.,Kanazawa University
Journal of Advanced Concrete Technology | Year: 2013

In the Hokuriku district, the effort toward the production of highly durable concrete mixtures using classified fine fly ash has just started as a part of ongoing countermeasures for the chloride attack and the alkali silica reaction (ASR). At a time when ASR deterioration phenomena are still progressing, the use of fly ash cement in concrete should be recommended and assertively be adopted as a regional approach for the mitigation of ASR problem especially in the Hokuriku District. In order to promote this mutual understanding and cooperation among the electric power companies, the national and local governments, the industrial association of ready-mixed concrete companies and the universities are indispensable. Accordingly, a joint-collaborative industry-academia-government research committee has been set up in January 2011. This paper focuses on the drawing from the current stage of ASR problem in the Hokuriku district and the development of highly durable fly ash concretes as its countermeasures. Copyright © 2013 Japan Concrete Institute. Source

Otani K.,Doshisha University | Baba Y.,Doshisha University | Nagaoka N.,Doshisha University | Ametani A.,Doshisha University | Itamoto N.,Hokuriku Electrical Power Company
Electric Power Systems Research | Year: 2014

Recently, Ala et al. (2008) [7] have proposed a soil ionization model, on the basis of the dynamic soil-resistivity model of Liew and Darveniza (1974) [16], for finite-difference time-domain (FDTD) computations, and tested the validity of the model against experiments on a single vertical grounding conductor. In the model, the resistivity of each soil-representing cell is controlled by the instantaneous value of the electric field there and time. In this paper, in order to test the validity of this model more thoroughly, it has been applied to analyzing the surge responses of different grounding electrodes: a horizontal grounding conductor of lengths 8.1 m and 34 m, a vertical grounding conductor of lengths 1 m and 1.5 m, and four parallel vertical conductors of length 3.05 m, buried in different-resistivity soils. The FDTD-computed responses agree reasonably well with the corresponding ones measured by Sekioka et al. (1998) [17], Asaoka et al. (2005) [19], Geri et al. (1992) [23], and Bellaschi et al. (1942) [24]. © 2014 Elsevier B.V. Source

Sugimoto H.,Hokuriku Electrical Power Company
IEEJ Transactions on Power and Energy | Year: 2010

Distribution surge arresters are often damaged by lightning strokes, in particular, winter lightning. An overhead ground wire (OGW) is one of effective measures against surge arrester failures. However, adding the conventional OGW to existing overhead power distribution lines needs the power interruption for construction as well as high costs because of installing them above phase conductors. Experimental results show that a covered conductor for distribution lines is more difficult to attract lightning than a bare conductor. Moreover, lightning strokes to distribution pole heads occupied over 90% of all lightning strokes in the observation result of lightning strokes to actual distribution lines without the conventional OGW, and lightning strokes to power lines were hardly observed. These results indicate that the pole heads shield the power Unes from direct lightning strokes. Therefore the author studies the application of an OGW under the distribution lines (UGW) for reducing surge arrester failures. The lightning performance of the UGW is estimated by the Electro-Magnetic Transients Program (EMTP) and its effectiveness is demonstrated. The measure is expected to cut costs of construction and maintenance for lightning protection. © 2010 The Institute of Electrical Engineers of Japan. Source

Yamagishi Y.,Hokuriku Electrical Power Company | Fujii Y.,University of Tokyo
IEEJ Transactions on Power and Energy | Year: 2012

High penetration of renewable energy may affect electric power system, because the variations in renewable energy power generations are affected by climate and relatively higher than those of conventional plants. Meanwhile, the future of global economic conditions and technological progress are very large uncertainties. It is difficult to find out the optimal solution based on current conditions. In this paper, an optimal power generation mix model is proposed, which can properly deal the essence of real conditions and carry out a number of simulations efficiently. In order to illustrate the proposed model, several parameter analysis cases, such as CO 2 emission constraints, fuel prices, costs of PV and storage facilities, and differences by years are studied. © 2012 The Institute of Electrical Engineers of Japan. Source

Shibata H.,Hokuriku Electrical Power Company
IEEJ Transactions on Power and Energy | Year: 2015

Traditionally, there are close relation between load dispatching operation of power system and meteorological phenomena, such as demand fluctuation and temperature, hydro power generation fluctuation and precipitation, and faults and extreme weather like lightnings or typhoon. Load dispatching operators of power system, by gathering and utilizing available meteorological information, continuously monitor the constantly changing power demand and the power plant operation level to perform power supply demand management and power system operation. Considering the evolving environment of the load dispatching operations, our R&D Investigation Committee examined the relation between load dispatching operation and meteorological information, the collection method and utilization of meteorological information, and the changes in load dispatching operation caused by the further introduction of renewable energy. Moreover, we have summarized possible issues and future visions on the expansion of renewable energy. © 2015 The Institute of Electrical Engineers of Japan. Source

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