3,178 research outputs found

    A Backend Framework for the Efficient Management of Power System Measurements

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    Increased adoption and deployment of phasor measurement units (PMU) has provided valuable fine-grained data over the grid. Analysis over these data can provide insight into the health of the grid, thereby improving control over operations. Realizing this data-driven control, however, requires validating, processing and storing massive amounts of PMU data. This paper describes a PMU data management system that supports input from multiple PMU data streams, features an event-detection algorithm, and provides an efficient method for retrieving archival data. The event-detection algorithm rapidly correlates multiple PMU data streams, providing details on events occurring within the power system. The event-detection algorithm feeds into a visualization component, allowing operators to recognize events as they occur. The indexing and data retrieval mechanism facilitates fast access to archived PMU data. Using this method, we achieved over 30x speedup for queries with high selectivity. With the development of these two components, we have developed a system that allows efficient analysis of multiple time-aligned PMU data streams.Comment: Published in Electric Power Systems Research (2016), not available ye

    Siting Power Plants: Recent Experience in California and Best Practices in Other States

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    Compares California's power plant siting with results in other states. Includes interviews with California state agency representatives, developers and process mediators. Part of a series of research reports that examines energy issues facing California

    Regulatory governance and sector performance : methodology and evaluation for Electricity distribution in Latin America

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    This paper contributes to the literature that explores the link between regulatory governance and sector performance. The paper develops an index of regulatory governance and estimates its impact on sector performance, showing that indeed regulation and its governance matter. The authors use two unique databases: (i) the World Bank Performance Database, which contains detailed annual data for 250 private and public electricity companies in Latin America and the Caribbean; and (ii) the Electricity Regulatory Governance Database, which contains data on several aspects of the governance of electricity agencies in the region. The authors run different models to explain the impacts of change in ownership and different characteristics of the regulatory agency on the performance of the utilities. The results suggest that the mere existence of a regulatory agency, regardless of the utilities'ownership, has a significant impact on performance. Furthermore, after controlling for the existence of a regulatory agency, the ownership dummies are still significant and with the expected signs. The authors propose an experience measure in order to identify the gradual impact of the regulatory agency on utility performance. The results confirm this hypothesis. In addition, the paper explores two different measures of governance, an aggregate measure of regulatory governance, and an index based on principal components, including autonomy, transparency, and accountability. The findings show that the governance of regulatory agencies matters and has significant effects on performance.National Governance,Infrastructure Regulation,Governance Indicators,Banks&Banking Reform,Emerging Markets

    RELIABILITY EVALUATION OF A WIND INTEGRATED POWER SYSTEM WITH COMPRESSED AIR ENERGY STORAGE

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    World-wide environmental concerns about green-house gas emissions from conventional generation sources have led to an increase in renewable energy penetration in electric power systems. Wind energy as a form of renewable power generation is environmentally friendly and suitable for bulk power generation. Wind power sources however, are intermittent and stochastic in nature and their increased penetration in the electric power system will introduce major challenges to reliable planning and operation of electric power systems. Energy storage systems are receiving considerable attention as potential means to adequately harness the benefits from wind power by absorbing the variability and reducing or eliminating the uncertainty in renewable power generation. This thesis is focused on compressed air energy storage (CAES) which has a high potential to be used on a grid scale. The ability of the CAES to absorb the variability and mitigate the uncertainty associated with wind energy is explored. The development of a suitable reliability model for the operation of the CAES is presented which proposes a hybrid approach by integrating a Monte Carlo Simulation (MCS) method with an analytical technique. The MCS technique is used to model the state of charge (SOC) of the CAES during the charging operation while recognizing the time chronology and the correlation between the variation in the wind, the load and the SOC of the storage. The analytical technique utilizes a period analysis to quantitatively assess the system adequacy for the diurnal and seasonal sub-periods under consideration. The diurnal analysis with sub-periods within a day captures the operation of the CAES on a daily cycle. The assumption is made that a seasonal period consists of a number of days with similar diurnal profile. This thesis presents the reliability and economic benefits of CAES being utilized in a number of ways to meet different objectives. The CAES can be operated in coordination with the wind resources to absorb the variability of wind power to promote renewable energy utilization in the system. A merchant owned CAES operated in an electricity market tries to exploit short term price difference to maximize profit from energy arbitrage. Different scenarios and operating strategies are used to investigate these objectives in this thesis. An energy management strategy for an annual study is developed and tested using appropriate data. The strategy divides the year into different seasons, and low cost energy is transferred from the off-peak season to the peak season. The effect of energy management is examined with respect to monetary profit and reliability improvement. Results obtained in this thesis and the conclusions drawn can be a valuable source of information to help utilities in effective and efficient planning of their systems considering CAES

    Reliability Monitoring Based on Higher-Order Statistics: A Scalable Proposal for the Smart Grid

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    The increasing development of the smart grid demands reliable monitoring of the power quality at different levels, introducing more and more measurement points. In this framework, the advanced metering infrastructure must deal with this large amount of data, storage capabilities, improving visualization, and introducing customer-oriented interfaces. This work proposes a method that optimizes the smart grid data, monitoring the real voltage supplied based on higher order statistics. The method proposes monitoring the network from a scalable point of view and offers a two-fold perspective based on the duality utility-prosumer as a function of the measurement time. A global PQ index and 2D graphs are introduced in order to compress the time domain information and quantify the deviations of the waveform shape by means of three parameters. Time-scalability allows two extra features: long-term supply reliability and power quality in the short term. As a case study, the work illustrates a real-life monitoring in a building connection point, offering 2D diagrams, which show time and space compression capabilities, as well

    Advanced Wide-Area Monitoring System Design, Implementation, and Application

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    Wide-area monitoring systems (WAMSs) provide an unprecedented way to collect, store and analyze ultra-high-resolution synchrophasor measurements to improve the dynamic observability in power grids. This dissertation focuses on designing and implementing a wide-area monitoring system and a series of applications to assist grid operators with various functionalities. The contributions of this dissertation are below: First, a synchrophasor data collection system is developed to collect, store, and forward GPS-synchronized, high-resolution, rich-type, and massive-volume synchrophasor data. a distributed data storage system is developed to store the synchrophasor data. A memory-based cache system is discussed to improve the efficiency of real-time situation awareness. In addition, a synchronization system is developed to synchronize the configurations among the cloud nodes. Reliability and Fault-Tolerance of the developed system are discussed. Second, a novel lossy synchrophasor data compression approach is proposed. This section first introduces the synchrophasor data compression problem, then proposes a methodology for lossy data compression, and finally presents the evaluation results. The feasibility of the proposed approach is discussed. Third, a novel intelligent system, SynchroService, is developed to provide critical functionalities for a synchrophasor system. Functionalities including data query, event query, device management, and system authentication are discussed. Finally, the resiliency and the security of the developed system are evaluated. Fourth, a series of synchrophasor-based applications are developed to utilize the high-resolution synchrophasor data to assist power system engineers to monitor the performance of the grid as well as investigate the root cause of large power system disturbances. Lastly, a deep learning-based event detection and verification system is developed to provide accurate event detection functionality. This section introduces the data preprocessing, model design, and performance evaluation. Lastly, the implementation of the developed system is discussed

    Assessment of industrial applications for fuel cell cogeneration systems

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    The fuel cell energy systems are designed with and without a utility connection for emergency back-up power. Sale of electricity to the utility during periods of low plant demand is not considered. For each of the three industrial applications, conceptual designs were also developed for conventional utility systems relying on purchased electric power and fossil-fired boilers for steam/hot water. The capital investment for each energy system is estimated. Annual operating costs are also determined for each system. These cost estimates are converted to levelized annual costs by applying appropriate economic factors. The breakeven electricity price that would make fuel cell systems competitive with the conventional systems is plotted as a function of naphtha price. The sensitivity of the breakeven point to capital investment and coal price is also evaluated

    Evaluation of selected chemical processes for production of low-cost silicon

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    Plant construction costs and manufacturing costs were estimated for the production of solar-grade silicon by the reduction of silicon tetrachloride in a fluidized bed of seed particles, and several modifications of the iodide process using either thermal decomposition on heated filaments (rods) or hydrogen reduction in a fluidized bed of seed particles. Energy consumption data for the zinc reduction process and each of the iodide process options are given and all appear to be acceptable from the standpoint of energy pay back. Information is presented on the experimental zinc reduction of SiCl4 and electrolytic recovery of zinc from ZnCl2. All of the experimental work performed thus far has supported the initial assumption as to technical feasibility of producing semiconductor silicon by the zinc reduction or iodide processes proposed. The results of a more thorough thermodynamic evaluation of the iodination of silicon oxide/carbon mixtures are presented which explain apparent inconsistencies in an earlier cursory examination of the system

    A preliminary systems-engineering study of an advanced nuclear-electrolytic hydrogen-production facility

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    An advanced nuclear-electrolytic hydrogen-production facility concept was synthesized at a conceptual level with the objective of minimizing estimated hydrogen-production costs. The concept is a closely-integrated, fully-dedicated (only hydrogen energy is produced) system whose components and subsystems are predicted on ''1985 technology.'' The principal components are: (1) a high-temperature gas-cooled reactor (HTGR) operating a helium-Brayton/ammonia-Rankine binary cycle with a helium reactor-core exit temperature of 980 C, (2) acyclic d-c generators, (3) high-pressure, high-current-density electrolyzers based on solid-polymer electrolyte technology. Based on an assumed 3,000 MWt HTGR the facility is capable of producing 8.7 million std cu m/day of hydrogen at pipeline conditions, 6,900 kPa. Coproduct oxygen is also available at pipeline conditions at one-half this volume. It has further been shown that the incorporation of advanced technology provides an overall efficiency of about 43 percent, as compared with 25 percent for a contemporary nuclear-electric plant powering close-coupled contemporary industrial electrolyzers
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