Electric Power Utilities Research Articles

Notes on Contributors

Notes on Contributors

Network Security Assessments for Integrating Large-Scale Tidal Current and Ocean Wave Resources Into Future Electrical Grids

Marine energy, especially tidal current and ocean wave resources, bear immense potential for generating renewable power toward meeting global electricity needs. A number of conversion technologies have been successfully demonstrated worldwide and precommercial/commercial deployments are expected to appear in the near future. While electric power utilities foresee renewable technologies as a viable alternative to fossil fuels, marine energy technologies are generally excluded in their energy planning processes. Lack of technological preparedness and unavailability of device information are two major obstacles in that regard. This article provides an insight on how such novel schemes of power generation can be analyzed under conventional network planning exercises using generic information. The first study focuses on wave power integration along the coasts of Oregon, USA for the year 2019 and analyzes the Northwest electrical network. The second study considers both tidal current and ocean wave resources in South Korea for the years 2017 and 2022. The primary objective of these high-level grid scenario analysis is to identify the practical potential for longer term large-scale wave and/or tidal power generation, particularly focusing on the transmission networks. Steady-state (overloading and voltage deviations/collapses), time-domain (angular stability and dynamic voltage recovery characteristics), and small-signal (eigenvalue) stability analysis are carried out for these systems. Subsequent to establishing a number of study scenarios, N-1 contingencies and various suitable violation criteria are prepared, which are used in identifying the underlying network bottlenecks, especially within the coastal areas. Simplified generic dynamic models of tidal current and ocean wave devices are developed for the time-domain analysis. It is expected that similar studies, once conducted by the interested utilities, will equip them better toward considering marine energy in their future portfolios. In addition, device manufacturers and project developers will have greater confidence in the emerging marine energy market.

Defining a quality index for electric power utilities using multiple criteria decision support and time series analysis

This paper presents a hybrid multi-criteria method developed through the combination of the Analytical Hierarchy Process (AHP) and exponential smoothing techniques applied in time series forecasting. To illustrate its use, a model was developed with the aim of creating a quality index for electric power distribution utilities. The conclusions highlight the need to take into account the results obtained in the latest months for those utilities, but giving less attention to those obtained in the earlier months. This characteristic of the problem led to the idea of incorporating the mathematical formulation of the exponential smoothing into the aggregation function of the AHP. At the end, the utility company is given a score between 0 (zero) and 10 (ten).

A Policy-Driven Method for IT Infrastructure Selection in Power Distribution Automation System

Electric power utilities invest heavily on their IT infrastructures; however, a large number of IT development projects fail. These failures are mostly caused by unsystematic and ad hoc designs, which can be summarized as lack of consistent design decision methods. This consistent design decision method should include a well-aligned IT development plan, considering requirements of the needed system. The literature shows the positive effect of this alignment of the IT requirements with the utility corporate policy, referred to as being Policy-Driven, here. This paper proposes a Policy-Driven design decision method for electric utility IT development projects, based on Wymorian T3SD theory of systems design. The proposed method possesses the following two features. First, it is highly sensitive to corporate policy of the utility, as our proposed method is able to assure the alignment of the IT development to utility corporate policy. Second, the proposed method is able to deal with the multiple disciplines related to the utility business; which includes at least: the utility core technology (power and automation), IT, human resources and financial matters

Asset maintenance planning in electric power distribution network using statistical analysis of outage data

The problems faced by electric power utilities in developing countries today is that the power demand is increasing rapidly whereas the supply growth is constrained by aging generating and distributing assets, scarce resources for constructing new ones and other societal issues. This has resulted in the need for constructing new additional generating plants and a more economic ways of planning and maintaining existing Generating and Electric power distribution assets. System planning and maintenance that is based on reliability – centred asset management approach had been adopted in this paper.Maintenance of critical asset is an essential part of asset management in distribution network. In most Electric utilities, planning for maintenance constitutes an essential parts of asset management. In this paper, an enhanced RCM methodology that is based on a quantitative statistical analysis of outage data Performed at system/component level for overall system reliability was applied for the identification of distribution components critical to system reliability. The conclusion from this study shows that it is beneficial to base asset maintenance management decisions on processed, analyzed and tested outage data.

タングステン電球の普及と東京電気の製品戦略

This paper aims to analyze the diffusion of tungsten filament lamps in Japan and the strategy of Tokyo Electric.In the United States, General Electric (GE) developed drawn-wire tungsten lamps in 1910. This electric lamp was three times more efficient (w/candlepower) and lasted twice as long as a carbon filament lamp. In Japan, Tokyo Electric, a GE subsidiary, introduced tungsten lamps in 1911.Initially, this lamp was adopted by small scale electric power companies/utilities in rural areas and new market entrants in major city. Some electric power utilities in major cities were cautious in the introduction of the tungsten lamp. The revenues of electric power utilities may have declined if there was no increase in the demand for electrical lighting service, corresponding to the improvement in the efficiency of electric lamps. Tokyo Electric promoted tungsten lamps, by introducing them in installations with more and brighter electric lights. This served the mutual interest they shared with the electric power utilities, which was building a large customer base for lamp manufacturers.During World War I, many electric power utilities decided to introduce tungsten lamps and the main channel of distribution of the tungsten lamp was through a cooperative relationship with Tokyo Electric. Electric power utilities succeeded in internalizing the effect of improved lamp efficiency by revising the advantageous rates for electric lighting service. The tungsten lamps that were launched in Japan were adjusted for lower efficiency and longer life spans, compared with their US counterparts. Electric power utilities tend to emphasize the longer life spans. Furthermore, Tokyo Electric marked down the lamp price while maintaining quality standards. Thus, Tokyo Electric, which pioneered the distribution of tungsten lamps in Japan, reaped significant profits.

Obtaining aluminum by the electrolysis with the solar radiation using

The aluminum production is one of the most energy-intensive processes of modern industry. The paper describes an attempt to obtain aluminum by electrolysis according to the Hall-Herout’s process without utilization of the industrial electric power but due to the cheap renewable environmentally friendly solar energy using. In this version, the electrolysis cell heating is performed by a concentrator of solar radiation while the electrolysis process is carried out with the direct electric current from a solar battery. It is shown that the Hall-Heroult’s process can be carried out by the solar energy exclusively. The proposed approach is a some contribution to development of alternative energy industry, in particular in its using in the classical metallurgy processes.

Fire Risk Analysis of Communication Room and some Suggestions

Abstract In this paper, fire risk has been analyzed to the daily electric power utilization, communication cabinet, battery cupboard and distribution cabinet installed in a communication room. Based on the present situation of the fire protection system in such kind of places, the design principles are offered. Also some suggestions to prevent fire attack from the daily electric power utilization, communication cabinet, battery cupboard and distribution cabinet in such kind of places are offered in this paper.

A Fast Outage Planning Method Focusing on Circuit Breakers Near Outage Facilities

SUMMARY Japanese electric power utilities installed many electric power facilities to respond to increasing power demand in the era of high economic growth. However, these facilities have aged about 40 years and should be replaced in the near future. The utilities will now have to replace larger numbers of facilities at the same time because of the increase in the number of power facilities to be replaced. Therefore, outage planning should be made more efficient. However, creating an outage plan requires time and labor, because the plan must specify (1) the outage schedule, (2) the power system configuration during outage operations, and (3) the system switching of the power system in order to conduct the outage operations. To solve these problems, a fast outage planning method focusing on circuit breakers near the outage facilities is proposed in this paper. Simulations run on IEEJ subtransmission system model I confirm the validity of the proposed method.

Using the fuzzy set theory to developing an environmental impact assessment index for a thermal power plant

Korean thermal power has had a prominent position in energy policies for the past decades. However, pollutants from the combustion of fossil fuels used in converting thermal energy into electrical energy have undesirable effect on the environment. This paper applies fuzzy set theory (FST) to identifying the significance of various environmental impacts using a specific case study of the electric power utilities in Korea. To this end, we consider nine environmental impacts: mortality, morbidity, forest, agricultural production, materials, visibility, thermal discharge water, landscape, and global warming. A survey of randomly sampled 1,000 households was administrated to obtain value judgments from FST about the environmental impacts of a thermal power plant. The overall results show that global warming is the most important attribute in environmental effect-related decision-making processes and followed by morbidity and mortality in order. The implications of the results for electric power utilities are also discussed. We found that the work and results can provide valuable insights for major decision making in energy and environmental planning of the electric power utilities.

Reliability enhancement using optimal distribution feeder reconfiguration

Failure statistics show that distribution networks engage the most contribution to the customer unavailability services. Optimal reconfiguration of distribution systems has many advantages like total power losses reduction, voltage profile enhancement, reliability improvement and so on. Therefore, in this paper a new multiobjective improved shuffled frog leaping algorithm (ISFLA) is proposed to investigate the distribution feeder reconfiguration (DFR) problem from the reliability enhancement point of view. Nevertheless, since the total cost of MW loss is an important and attractive subject to the electric power utilities, the total active power losses is also considered as an objective function in the investigations. Therefore, the objective functions of the problem to be optimized are system average interruption frequency index (SAIFI), system average interruption duration index (SAIDI), average energy not supplied (AENS) and the total active power losses. During the optimization process, the proposed ISFLA finds a set of non-dominated optimal solutions referred to Pareto optimal solutions that are kept in an external memory called repository. As the result of the conflicting behavior of the objective functions investigated, a fuzzy clustering technique is employed to control the size of the repository in the predetermined limits. The feasibility and the efficiency of the proposed method are examined by a standard distribution test system.

Energy policy and regional inequalities in the Brazilian economy

The objective of this paper is to evaluate the long-run regional impacts of the tariff policy of the Brazilian electric power sector. This sector has undergone a reform process that started in the 1990s. Since the beginning of the reform, two spatial trends of distribution of electric power tariffs have emerged among the Brazilian states, one of convergence and another of spatial divergence. These trends have been guided by the new electric power tariff policy and by the spatial features of the Brazilian economy, which is marked by a high degree of spatial concentration and hierarchical distribution of large markets. In addition, because of the presence of strong economies of scale, the recent electric power prices differentials might be caused by differentials in market size that provide better conditions for the achievement of economies of scale for electric power utility companies located in larger markets. Given the role of electric power as an important intermediate input in the production process and the interdependence between sectors, an Energy Interregional Computable General Equilibrium model was used to simulate the long-run regional impacts of electric power tariff policy in Brazil. The simulations showed that the heterogeneity of energy-intensity and the differentials of energy substitution drive the spatial impacts of changes in electric power prices. On the other hand, the recent trend of spatial dispersion of electric power prices might contribute to a decrease in the long-run economic growth and to an increase in the regional inequalities in Brazil.

The effect of the Fukushima nuclear accident on stock prices of electric power utilities in Japan

The purpose of this study is to investigate the effect of the accident at the Fukushima Daiichi nuclear power station, which is owned by Tokyo Electric Power Co. (TEPCO), on the stock prices of the other electric power utilities in Japan. Because the other utilities were not directly damaged by the Fukushima nuclear accident, their stock price responses should reflect the change in investor perceptions on risk and return associated with nuclear power generation. Our first finding is that the stock prices of utilities that own nuclear power plants declined more sharply after the accident than did the stock prices of other electric power utilities. In contrast, investors did not seem to care about the risk that may arise from the use of the same type of nuclear power reactors as those at the Fukushima Daiichi station. We also observe an increase of both systematic and total risks in the post-Fukushima period, indicating that negative market reactions are not merely caused by one-time losses but by structural changes in society and regulation that could increase the costs of operating a nuclear power plant.

Using layer of protection analysis to understand necessary safeguards for steam boiler operation

Most chemical process plants, petrochemical facilities, and electrical power utilities rely on steam boilers to provide motive power, electricity, and process steam for operations. Safe operation, startup, and shutdown of these boilers require many levels of operational/controls safeguards. The design and selection of safeguards is often guided by the original design of the boiler, equipment manufacturers, internal company standards, and recognized authoritative standards. In the United States, the National Fire Protection Association (NFPA) has promulgated NFPA 85 Boiler and Combustion Systems Hazards Code. This prescriptive code identifies necessary safeguards along with “listing” and “labeling” requirements for some components used as safeguards; however, the Safety Integrity Levels for the multiple safeguard systems have not been quantified. In this article, we use Layer of Protection Analysis methods along with generally accepted probabilities and frequencies of failures to provide a quantitative framework for an owner, operator, or manufacturer to use in designing or evaluating the multiple safeguards necessary for safe steam boiler operation. As part of the analysis, we have provided case studies of boiler failures with a discussion of how additional layers of protection may be either ineffective or missing. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012

Laboratory Study of the Lightning Attractive Width for Transmission Lines

This research focuses on an investigation of the attractive width of high voltage transmission lines to lightning strokes. In order to design the optimal lightning protection, the estimated number of lightning flashes to the line, which is based on its attractive width, needs to be determined. The investigation was performed using experiments with tested models at the Mississippi State University High Voltage Laboratory. For laboratory experiments, a total of 1,900 negative and positive switching impulse voltages were applied to a conducting rod, which represented a lightning downward leader. Different tested models of transmission lines on a scale of 1:100 were used. The effect of overhead ground wires, phase conductors, and the magnitude and polarity of lightning strokes were studied. The attractive width increased gradually with the height of overhead ground wires as well as the magnitude of the lightning stroke current. Impulse polarity had an impact on the attractive width and the attractive width for negative polarity was larger than that for positive polarity. The experimental results satisfactorily coincide with other published works, based on different methods and also with the actual transmission line observations. The new expressions of the attractive width of transmission lines, based on the experimental results, were established. The accurate estimation of the attractive width can help electric power utilities plan transmission systems reliably and economically. The detailed description of the background problem, methodology, experimental results, and analysis were presented in this paper.

The Quota and Analysis of Comprehensive Energy Consumption per Unit for Residential Buildings in Changsha

Using an appropriate evaluation index for energy consumption is advantageous for evaluating energy saving effect of buildings correctly and carrying out energy-saving action reasonably. As a result, it is important to establish a practical quota of energy consumption for promoting energy-saving emission reduction. Energy consumption for residential buildings has been influenced by the behavior of residents in the building largely, and has a higher uncertainty, so it brings great difficulty to researches. Considering the characteristics of residential buildings, this paper uses comprehensive energy consumption per unit as evaluation index. Based on the investigation results and related studies, the residential buildings in Changsha are analyzed with statistical methods, in order to know more about the energy consumption level and structure for the residential buildings in Changsha. This paper shows the characteristics of the energy consumption of the residential buildings in Changsha, and work out the range of the comprehensive energy consumption per unit. The result provides a reference to make out energy policy and enhance the management of energysaving. It can be also used to guide the residents have a reasonable electric power utilization.

Lightning occurrence characteristics in Japan for 17 years: observation results with lightning location systems of electric power utilities from 1992 to 2008

AbstractWe summarize the lightning data for 17 years from 1992 to 2008 obtained with lightning location systems of nine electric power utilities in Japan and analyze them. The observed annual number of lightning flashes of which the current is more than 10 kA is 400 000–800 000 and the 50% value of the cumulative distribution of lightning peak currents is about 23 kA in recent times. The variation of lightning occurrence characteristics by areas, seasons, and so on, is clarified. Comparison of the obtained data with those obtained by another lightning location system is also made. The relationship between lightning occurrence and climate is discussed. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Generating System Wellbeing Index Evaluation Using Genetic Algorithm

Reliability assessment of generation system is a crucial task used to be done using deterministic approaches. However, due to the practical limitations of these approaches, they have been gradually replaced by probabilistic techniques. Nevertheless, there is a considerable reluctance in many electric power utilities to completely abandon deterministic considerations. To fulfill the industry need, wellbeing analysis has been developed to combine the deterministic and the probabilistic approaches in a single framework. Analytical techniques or Monte Carlo Simulation have been used to evaluate wellbeing indices. However, analytical approaches are complicated and mathematically demanding and simulation technique requires a huge amount of computing time, and large memory size. This still prevents the utilities to benefit from the wellbeing framework. This paper presents a novel Genetic Algorithm (GA) based technique to calculate the wellbeing indices. Hopefully, this will encourage the industry to benefit from the wellbeing analysis. The features of the GA are utilized to collect and identify the health, marginal and at risk wellbeing states and to calculate the associated wellbeing indices. The proposed technique is applied to the IEEE-RBTS and the resulting wellbeing indices are compared to those obtained using a conventional analytical technique. The results show that the outcome of both techniques is virtually identical. The effect of the GA parameters on the wellbeing indices is examined. The proposed GA based technique in the manner applied in this study is simple, practical and valid to calculate the wellbeing indices.

Effects of Load Sector Demand Side Management Applications in Generating Capacity Adequacy Assessment

Electric power utilities are facing increasing infrastructure investment and awareness of environmental issues. Demand side management (DSM) can play an important role in meeting some of the challenges faced by electric power utilities in that it can be used to improve energy efficiency, system reliability, and security, reduce costs for both customers and utilities, and mitigate environmental damage. This paper applies load shifting on seven different customer load sectors and illustrates the effects of the various DSM measures on the load shapes and on the system reliability indices used in generating capacity adequacy assessment.

The Effect of the Fukushima Nuclear Accident on Stock Prices of Electric Power Utilities

The purpose of this study is to investigate the effect of the accident at the Fukushima Daiichi nuclear power station, which is owned by Tokyo Electric Power Co. (TEPCO), on the stock prices of the other electric power utilities in Japan. Because the other utilities were not directly damaged by the Fukushima nuclear accident, their stock price responses should reflect the change in investor perceptions on risk and return associated with nuclear power generation. Our first finding is that the stock prices of utilities that own nuclear power plants declined more sharply after the accident than did the stock prices of other electric power utilities. In contrast, investors did not seem to care about the risk that may arise from the use of the same type of nuclear power reactors as those at the Fukushima Daiichi station. We also observe an increase of both systematic and total risks in the post-Fukushima period, indicating that negative market reactions are not merely caused by one-time losses but by structural changes in society and regulation that could increase the costs of operating a nuclear power plant.