Power Company (power + company)

Distribution by Scientific Domains


Selected Abstracts


Application of DA-preconditioned FINN for electric power system fault detection

ELECTRICAL ENGINEERING IN JAPAN, Issue 2 2009
Tadahiro Itagaki
Abstract This paper proposes a hybrid method of deterministic annealing (DA) and fuzzy inference neural network (FINN) for electric power system fault detection. It extracts features of input data with two-staged precondition of fast Fourier transform (FFT) and DA. FFT is useful for extracting the features of fault currents while DA plays a key role in classifying input data into clusters in a sense of global classification. FINN is a more accurate estimation model than the conventional artificial neural networks (ANNs). The proposed method is successfully applied to data obtained by the Tokyo Electric Power Company (TEPCO) power simulator. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(2): 39, 46, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20497 [source]


Measurement and computation of ground resistances at 161/23.9,11.95-kV indoor-type substations

EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2009
Cheng-Nan Chang
Abstract The purpose of this paper is to compare the calculated and actual ground resistances at two 161/23.9,11.95-kV indoor-type substations in the system of Taiwan Power Company. For the calculated ground resistances, one- and two-layer soil models based on Sverak and Schwarz equations, the method of images and the current distribution electromagnetic grounding and soil structure analysis (CDEGS) program are performed. As for the actual ground resistances, they are found by subtracting the measured ground resistances which are obtained by the fall-of-potential method from the earth mutual resistances. As a result, the calculated ground resistance based on the method of images as the observation point located at the lower layer of the two-layer soil model is approximately equal to the actual ground resistance measured by the fall-of-potential method with the potential electrode buried at the lower layer. In addition, the ground potential rises (GPRs) at both substations are computed and compared with the minimum touch voltages for assessing the grounding system safety. The result shows that the design of the grounding system at both substations is unsafe under the one-layer soil model for humans with 50 and 70,kg body weight. Copyright © 2008 John Wiley & Sons, Ltd. [source]


PREPARE: seeking systemic solutions for technological crisis management

KNOWLEDGE AND PROCESS MANAGEMENT: THE JOURNAL OF CORPORATE TRANSFORMATION, Issue 2 2005
Beverly J. DavisArticle first published online: 2 JUN 200
America's private sector faces an unprecedented challenge in the wake of the 9/11 terrorist attacks. For the first time in the nation's history, its business assets, workers, and critical infrastructures are on the front lines of the battlefield,key targets, and possibly pathways, for future attacks. With terrorism, unconventional declaration of war can be waged, chaos created, and borders crossed by attacking our information highways. Although the catastrophic 9/11 attacks shifted our attention to the United States, the fact remains that Internet attacks against private and public organizations around the world leapt 28% in the 6 months after 9/11. These attacks targeted technology, financial services, and power companies. In order to ,seek to understand our enemies', the PREPARE Model of Technological Crisis Management (TCM) along with the application of the Johari Window psychology model will offer business leaders techniques to increase awareness of potential threats to their businesses. The best practice TCM model, a model of continuous process and analysis, takes business cyber-security to a new level, not only identifying the risks and threats to businesses, but also assessing and creating systemic plans to respond to those risks. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Yardstick Cost Comparison and Economies of Scale and Scope in Japan's Electric Power Industry

ASIAN ECONOMIC JOURNAL, Issue 4 2004
Takanori Ida
This paper utilizes a fixed-effects model of panel data analysis and estimates the translog cost function of the Japanese electric power industry from 1978 to 1998. First, we investigate whether the Japanese electric power industry is naturally monopolistic. We find that all electric power companies still benefit from both scale and scope economies and therefore, this industry remains a naturally mono-polistic industry. Second, in order to apply the idea of yardstick-type competition to a naturally monopolistic industry where costs are quite different between companies, we introduce two kinds of cost-comparison coefficients, one for the individually specific effects and the other for scale and scope economies. [source]