Energy Network System Research Articles

A multi-objective solution algorithm for optimum utilization of Smart Grid infrastructure towards social welfare

This paper proposes an optimization model to maximize social welfare by standardizing the operating conditions with an overall improvement of dynamic stability of power markets endowed with Smart Grid communication technology. The state space based model developed along with the proposed methodology maximizes load catering and simultaneously minimizes the operating standard constrained generation cost to restore power market equilibrium even in the most inadvertent states of the Energy System Network. For optimum utilization of smart metering facility, the model effectively involves resources like demand response, generation surplus and an efficient methodology to optimize the Market Clearing Price (MCP) as well as profit of the market participants by effective categorization. The power market dynamic price equilibrium has been estimated by forming Jacobian of the sensitivity matrix to regulate the state variables for the standardization of the quality of solution. A novel load curtailment strategy has also been proposed to amalgam stability restoring shedding with profit retentive load cut. The model has been tested in IEEE 30 bus system in comparison with standard curtailment based optimization technique to produce encouraging results.

Wind Energy Based Packet Energy System

This paper proposes a wind turbine and battery storage based packet energy system. The proposed energy packet network can be used to make renewable energy sources more practical and supply energy on demand. The flow of energy in the energy packet network is controlled by a Smart Energy Dispatching Centres (SEDC). SEDCs receive the energy requests from the customers and it tries to optimize the energy flows by making the best use of renewable energy resources, existing price and policies. The proposed energy system can take energy flow instructions from a SEDC. In the present analysis a small wind energy system with battery storage has been simulated in Matlab/Simulink. The system has been modelled using low order transfer functions. Random switching has been done to get energy packets from the model. A prototype of the battery based energy storage system has been designed and implemented. Lab tests and simulation results indicates that the designed packet energy network system is able to provide energy packet as required by the grid. Additionally the output power from a very large energy packet network is also found to be stable with the existence of large load fluctuation.

S084023 遺伝的アルゴリズムによる自然エネルギー平準化システム内の分散型電源の最適化([S084-02]分散型エネルギーシステム(2))

S084023 遺伝的アルゴリズムによる自然エネルギー平準化システム内の分散型電源の最適化([S084-02]分散型エネルギーシステム(2))

Development of approach for reliability assessment of pipeline network systems

The aim of the work presented in this paper is to develop a common scientific methodology for the assessment of reliability of the pipeline network energy systems. The developed methodology is applicable for district heating, gas and oil supply networks. The reliability of all these systems depends on the degradation mechanisms and structural integrity of pipes. Structural integrity is influenced by loadings, defined by thermal–hydraulic processes. The reliability of energy network systems also depends on reliability of the installed equipment and the supply source. The reliability of pipeline networks is treated as a complex task. Consequently, the developed methodology includes three types of analyses: probabilistic mathematical, deterministic thermal–hydraulic and deterministic-probabilistic structural integrity analyses. As a pilot study, the application of the developed methodology for the analysis of Kaunas (Lithuania) district heating system was performed. The main results of this pilot study are presented in the paper. Although the original intention is to apply the developed methodology for the assessment of the reliability of the Lithuanian energy systems, in general, the methodology is applicable for any pipeline network system in any country.

Integrated battery controller for distributed energy system

In this article, an improved integrated battery energy storage system (BESS) controller for distributed energy system is presented. The BESS is integrated in parallel with the full wave bridge converter into the distributed energy system network. In a normal operating mode, the BESS serves as a power conditioner as well as an active power filter in a distributed power system network. This work presents BESS controller which is designed for regulating the state of charge of the batteries and also to manage the active power in a distributed power system network. The off peak load energy is used to recover the batteries’ state of charge through the BESS controller. In this BESS controller, the constant current–constant voltage (CC–CV) mode is used and it helps to keep the batteries’ state of charge conditions for improving the reliability of the distributed power system system. This control strategy is incorporated into the main converter. The controller helps in managing the phase, amplitude and waveform of the current and voltage on the distributed power system network. The controller ensures the power quality and also assists in improving the power factor with respect to the utility for the intermittent distributed generation as well as the load. In this article, the test results of a prototype system are presented, which validates the proposed controller strategy of BESS in a distributed power system network.

Model Analysis of Energy Network System in Zero Emission Industrial Park

The aim of this study was to evaluate energy saving in cases of introducing both a cogeneration system and an energy network in Kokubo Industrial Park. The industrial park has implemented zero emission activities since 1992. The energy data of 22 factories were classified into steam, hot water, heating, cooling and electric power on the basis of interviews. The author developed an energy network model based on linear programming, so as to minimize the total system cost. The industrial park was divided into a 10,000 square meter mesh in order to take steam transport into consideration. Three cases were investigated. The ratio of energy saving to demand reached 22% compared with the reference system. It was found that the energy network system could correspond to the energy demand seasonally. This is useful for the stable supply of energy, prevention of air pollution, and improvement of urban design.

Operating schedule of a combined energy network system with fuel cell

The chromosome model showing system operation pattern is applied to GA (genetic algorithm), and the method of optimization operation planning of energy system is developed. The optimization method of this operation planning was applied to the compound system of methanol-steam-reforming-type fuel cell, geothermal heat pump and the electrolysis tank of water. The operation planning was performed for the energy system using the energy demand pattern of the individual residence of Sapporo city. From analysis results, the amount of outputs of a solar module and the relation of the operation cost of the system, which are changed by the weather were clarified. The representation day in February of the ratio of the operation cost in case of (0% of output rates) the rainy weather to the time of fine weather (100% of output rates) is 1.12. And the representation day in July is 1.71. Furthermore, the optimal capacity of accumulation of electricity and thermal storage was estimated, and they are 308 and 23 MJ, respectively. Copyright © 2006 John Wiley & Sons, Ltd.

1013 住民参加型家庭用新エネルギー供給システムの開発

Neighboring Co-Generation (NCG) System is created to present the comfortable and high quality living environment, using combined power and heat (CHP) technologies. The key concept of this system is to connect the home and home for one loop of heat transfer line and level or manage the demand of heat consumption in the small community with high internet practice. This system is expected to optimum the heat utilization and to aim the higher efficiency than stand alone of the distributed generation system. And further expectation for the system is that this system will contribute to save energy, which is equivalent to abate over 50% of CO2 emission from homes due to the higher efficiency of CHP. In urban area of Kinki area, approximate 55% inhabitants live in condominium. Then introduction of the system will be expected to be able to cntribute to achieve CO2 abatement target for the Kyoto protocol. This system will also increase the availability of the co-generation system and improve the heat use management. For the realization of this system, the study group is established in AIST Kansai Center recently and the combination technologies of heat supply, heat storage and air conditioning are under development besides the Information Technologies (IT) application. This paper describes the new idea of energy supply system with participation of inhabitants for the energy network system.

00/00208 Applications of artificial neural networks in energy systems. A review

00/00208 Applications of artificial neural networks in energy systems. A review

Applications of artificial neural networks in energy systems

Artificial neural networks are widely accepted as a technology offering an alternative way to tackle complex and ill-defined problems. They can learn from examples, are fault tolerant in the sense that they are able to handle noisy and incomplete data, are able to deal with non-linear problems and, once trained, can perform prediction and generalisation at high speed. They have been used in diverse applications in control, robotics, pattern recognition, forecasting, medicine, power systems, manufacturing, optimisation, signal processing and social/psychological sciences. They are particularly useful in system modelling, such as in implementing complex mappings and system identification. This paper presents various applications of neural networks in energy problems in a thematic rather than a chronological or any other order. Artificial neural networks have been used by the author in the field of solar energy, for modelling the heat-up response of a solar steam-generating plant, for the estimation of a parabolic trough collector intercept factor, for the estimation of a parabolic trough collector local concentration ratio and for the design of a solar steam generation system. They have also been used for the estimation of heating loads of buildings. In all those models, a multiple hidden layer architecture has been used. Errors reported in these models are well within acceptable limits, which clearly suggest that artificial neural networks can be used for modelling in other fields of energy production and use. The work of other researchers in the field of energy is also reported. This includes the use of artificial neural networks in heating, ventilating and air-conditioning systems, solar radiation, modelling and control of power generation systems, load forecasting and prediction, and refrigeration.

Performance of a tube-wall type reactor for transforming heat energy into chemical energy efficiently

The cyclohexane/benzene/hydrogen chemical heat pump (CHP) cycle is a hopeful way of backing up the UT-3 system or the world energy network system for heat and hydrogen storage. To realize the CHP system, a tube-wall type reactor (TWR) has been proposed to transform thermal energy into chemical energy efficiently. The catalyst volume in the TWR was six times smaller and the pressure drop was 100 times smaller than those of a classical fixed bed reactor (FBR). For reactor performances over 42 kW the TWR also became smaller than the FBR. It will be possible to design a high performance TWR by improving the reactivity. The catalyst layers have been formed on the surfaces of fin-tube and fin-plate type heat exchangers.

Assessment of Effectiveness of Renewable Energy Systems in Mitigating Global Warming Based on Net Energy Analysis.

Renewable energy technologies are expected to be capable of contributing significantly to solution of the global warming problem because of their inherent advantages : resources can be considered as virtually inexhaustible and no carbon dioxide release will occur during the energy conversion process. On the other hand, their generally high energy cost due to low availability inevitably makes it difficult, under the prevailing decision-making process based on conventional performance indices, to exploit their advantages on the large scale of substitution for conventional energy technologies such as fossil fuel or nuclear power. In the present paper, we introduce a methodology based on indices derived from net energy analysis to assess the significance of renewable energy technologies as an option to mitigate global warming as well as to satisfy future energy demand, and discuss the effectiveness of some new carbon-free energy technologies, including the proposed Hydrogen-Based Global Renewable Energy Network System.

Coal Conversion Technologies: Some Health and Environmental Effects

Several technologies to convert coal to liquid and gaseous fuels are being developed in the United States, some with support from the Department of Energy. Substitution of these technologies for those currently being used will produce different health and environmental hazards. In this article, selected health and environmental effects of four coal conversion and four existing technologies are compared. For each technology, the emission estimates for complete fuel cycles, including all steps in fuel use from extraction to the end use of space and water heating by electricity or direct combustion, were prepared by means of the Brookhaven Energy System Network Simulator model. Quantitative occupational health and safety estimates are presented for the extraction, transportation, distribution, processing, and conversion activities associated with each technology; also included are some public health damage estimates arising from fuel transportation and air pollution impacts. Qualitative estimates of health damage due to polycyclic organic matter and reduced sulfur are discussed. In general, energy inefficiencies, environmental residuals, and hence implied environmental effects and health damage increase in the order: (i) direct combustion of natural gas and oil, (ii) direct combustion of synthetic gas and oil, (iii) central-station electric power produced from synthetic gas, (iv) central-station electric power produced from coal, and (v) central-station electric power produced by the combustion of synthetic liquid fuels. The compliance and conflict of these technologies with the amendments of the Clean Air Act and other legislation are discussed.

Health effects from the nuclear fuel cycle and other sources in perspective

The data base for each process of the nuclear fuel cycle has been updated as a part of the Committee on Nuclear and Alternative Energy Systems (CONAES) at Brookhaven National Laboratory (BNL). The BNL Energy System Network Simulator (ESNS) was modified to accommodate the new data, and methodology was developed for estimating population dose and health effects resulting from atmosphere releases of radioactive materials from the nuclear fuel cycle.

Qualitative indices for the system voltage and reactive power control

Both in off-line and in on-line operation of energy systems, the computer has become an important ally of the engineer. However, results of calculations often obscure properties of steady state of the network. What will the power system network reaction be if one or more nodal voltage varies? How will these variations be reflected at certain nodes? How can one find rapidly a good operating strategy, even if not the best? Answers could be given by using non-linear programming procedures. Nevertheless, fast solutions can be found if heuristic techniques are introduced. This paper proposes to provide the power engineer with a class of indices which clears qualitatively the steady state of energy system network.