917 resultados para Predictive Control Strategy
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This paper concern the development of a stable model predictive controller (MPC) to be integrated with real time optimization (RTO) in the control structure of a process system with stable and integrating outputs. The real time process optimizer produces Optimal targets for the system inputs and for Outputs that Should be dynamically implemented by the MPC controller. This paper is based oil a previous work (Comput. Chem. Eng. 2005, 29, 1089) where a nominally stable MPC was proposed for systems with the conventional control approach where only the outputs have set points. This work is also based oil the work of Gonzalez et at. (J. Process Control 2009, 19, 110) where the zone control of stable systems is studied. The new control for is obtained by defining ail extended control objective that includes input targets and zone controller the outputs. Additional decision variables are also defined to increase the set of feasible solutions to the control problem. The hard constraints resulting from the cancellation of the integrating modes Lit the end of the control horizon are softened,, and the resulting control problem is made feasible to a large class of unknown disturbances and changes of the optimizing targets. The methods are illustrated with the simulated application of the proposed,approaches to a distillation column of the oil refining industry.
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Methylobacterium mesophilicum, originally isolated as an endophytic bacterium from citrus plants, was genetically transformed to express green fluorescent protein (GFP). The GFP-labeled strain of M. mesophilicum was inoculated into Catharanthus roseus (model plant) seedlings and further observed colonizing its xylem vessels. The transmission of this endophyte by Bucephalogonia xanthophis, one of the insect vectors that transmit Xylella fastidiosa subsp. pauca, was verified by insects feeding from fluids containing the GFP bacterium followed by transmission to plants and isolating the endophyte from C. roseus plants. Forty-five days after inoculation, the plants exhibited endophytic colonization by M. mesophilicum, confirming this bacterium as a nonpathogenic, xylem-associated endophyte. Our data demonstrate that M. mesophilicum not only occupy the same niche of X. fastidiosa subsp. pauca inside plants but also may be transmitted by B. xanthophis. The transmission, colonization, and genetic manipulation of M. mesophilicum is a prerequisite to examining the potential use of symbiotic control to interrupt the transmission of X. fastidiosa subsp. pauca, the bacterial pathogen causing Citrus variegated chlorosis by insect vectors.
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This paper presents new integrated model for variable-speed wind energy conversion systems, considering a more accurate dynamic of the wind turbine, rotor, generator, power converter and filter. Pulse width modulation by space vector modulation associated with sliding mode is used for controlling the power converters. Also, power factor control is introduced at the output of the power converters. Comprehensive performance simulation studies are carried out with matrix, two-level and multilevel power converter topologies in order to adequately assert the system performance. Conclusions are duly drawn.
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This paper presents a variable speed autonomous squirrel cage generator excited by a current-controlled voltage source inverter to be used in stand-alone micro-hydro power plants. The paper proposes a system control strategy aiming to properly excite the machine as well as to achieve the load voltage control. A feed-forward control sets the appropriate generator flux by taking into account the actual speed and the desired load voltage. A load voltage control loop is used to adjust the generated active power in order to sustain the load voltage at a reference value. The control system is based on a rotor flux oriented vector control technique which takes into account the machine saturation effect. The proposed control strategy and the adopted system models were validated both by numerical simulation and by experimental results obtained from a laboratory prototype. Results covering the prototype start-up, as well as its steady-state and dynamical behavior are presented. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
This paper presents a distributed model predictive control (DMPC) for indoor thermal comfort that simultaneously optimizes the consumption of a limited shared energy resource. The control objective of each subsystem is to minimize the heating/cooling energy cost while maintaining the indoor temperature and used power inside bounds. In a distributed coordinated environment, the control uses multiple dynamically decoupled agents (one for each subsystem/house) aiming to achieve satisfaction of coupling constraints. According to the hourly power demand profile, each house assigns a priority level that indicates how much is willing to bid in auction for consume the limited clean resource. This procedure allows the bidding value vary hourly and consequently, the agents order to access to the clean energy also varies. Despite of power constraints, all houses have also thermal comfort constraints that must be fulfilled. The system is simulated with several houses in a distributed environment.
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This paper presents a new predictive digital control method applied to Matrix Converters (MC) operating as Unified Power Flow Controllers (UPFC). This control method, based on the inverse dynamics model equations of the MC operating as UPFC, just needs to compute the optimal control vector once in each control cycle, in contrast to direct dynamics predictive methods that needs 27 vector calculations. The theoretical principles of the inverse dynamics power flow predictive control of the MC based UPFC with input filter are established. The proposed inverse dynamics predictive power control method is tested using Matlab/Simulink Power Systems toolbox and the obtained results show that the designed power controllers guarantees decoupled active and reactive power control, zero error tracking, fast response times and an overall good dynamic and steady-state response.
Resumo:
This paper describes the implementation of a distributed model predictive approach for automatic generation control. Performance results are discussed by comparing classical techniques (based on integral control) with model predictive control solutions (centralized and distributed) for different operational scenarios with two interconnected networks. These scenarios include variable load levels (ranging from a small to a large unbalance generated power to power consumption ratio) and simultaneously variable distance between the interconnected networks systems. For the two networks the paper also examines the impact of load variation in an island context (a network isolated from each other).
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Solar photovoltaic systems are an increasing option for electricity production, since they produce electrical energy from a clean renewable energy resource, and over the years, as a result of the research, their efficiency has been increasing. For the interface between the dc photovoltaic solar array and the ac electrical grid is necessary the use of an inverter (dc-ac converter), which should be optimized to extract the maximum power from the photovoltaic solar array. In this paper is presented a solution based on a current-source inverter (CSI) using continuous control set model predictive control (CCS-MPC). All the power circuits and respective control systems are described in detail along the paper and were tested and validated performing computer simulations. The paper shows the simulation results and are drawn several conclusions.
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The Bush administration announced its 2006 National Drug Control Strategy in the first city to legalize marijuana, a decision that wasn't entirely coincidental. John P. Walters, director of the Office of National Drug Control Policy, who selected a youth drug treatment center here as the site for the announcement, said Denver represented 'a model of what we see and what we're trying to face'. The 2006 strategy calls for a continuation of the Bush administration's balance of reducing demand through, among other things, drug-prevention campaigns, and reducing supply by securing the Mexican border. Mr. Walters described the strategy, implemented in 2001, as a success, pointing to studies showing that overall teenage drug use has dropped since then by 19 per cent. Use of methamphetamine, LSD and steroids also have declined, he said.This resource was contributed by The National Documentation Centre on Drug Use.
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Iowa's Drug Control Strategy produced by Office of Drug Control Policy for the 2007 year.
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The attached annual report is submitted in satisfaction of Chapter 80E.1 of the Code of Iowa which directs the Drug Policy Coordinator to monitor and coordinate all drug prevention, enforcement and treatment activities in the state. Further, it requires the Coordinator to submit an annual report to the Governor and Legislature concerning the activities and programs of the Coordinator, the Governor’s Office of Drug Control Policy and all other state departments with drug enforcement, substance abuse treatment, and prevention programs. Chapter 80E.2 establishes the Drug Policy Advisory Council (DPAC), chaired by the Coordinator, and consisting of a prosecuting attorney, substance abuse treatment specialists, law enforcement officers, a prevention specialist, a judge and representatives from the departments of corrections, education, public health, human services, public safety and human rights. This report and strategy were in developed in consultation with the DPAC.
Resumo:
The attached annual report is submitted in satisfaction of Chapter 80E.1 of the Code of Iowa which directs the Drug Policy Coordinator to monitor and coordinate all drug prevention, enforcement and treatment activities in the state. Further, it requires the Coordinator to submit an annual report to the Governor and Legislature concerning the activities and programs of the Coordinator, the Governor’s Office of Drug Control Policy and all other state departments with drug enforcement, substance abuse treatment, and prevention programs. Chapter 80E.2 establishes the Drug Policy Advisory Council (DPAC), chaired by the Coordinator, and consisting of a prosecuting attorney, substance abuse treatment specialists, law enforcement officers, a prevention specialist, a judge and representatives from the departments of corrections, education, public health, human services, public safety and human rights. This report and strategy were in developed in consultation with the DPAC.
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The 2009 Iowa Drug Control Strategy is the annual report and Drug Control Strategy for the State of Iowa, produced in accordance with Iowa law, by the Governor's Office of Drug Control Policy, in cooperation with the Drug Policy Advisory Council.
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Iowa's Drug Control Strategy serves as a comprehensive blueprint for coordinated prevention, treatment, and enforcement actions to protect citizens from the dangers posed by substance abuse. This holistic plan, developed by Iowa's Drug Policy Advisory Council, embraces a performance-oriented process to align resources with long-term goals, and supports three desired results: All Iowans are healthy and drug-free, Iowa communities are free from illegal drugs, all Iowans are safe from drug abusing offenders. This report also contains a mix of recent accomplishments and pending challenges.
Resumo:
The 2011 Iowa Drug Control Strategy is submitted in satisfaction of Chapter 80E.1 of the Code of Iowa which directs the Drug Policy Coordinator to monitor and coordinate all drug prevention, enforcement and treatment activities in the state. Further, it requires the Coordinator to submit an annual report to the Governor and Legislature concerning the activities and programs of the Coordinator, the Governor’s Office of Drug Control Policy and all other state departments with drug enforcement, substance abuse treatment, and prevention programs. Chapter 80E.2 establishes the Drug Policy Advisory Council (DPAC), chaired by the Coordinator, and consisting of a prosecuting attorney, substance abuse treatment specialist, law enforcement officer, prevention specialist, judge and representatives from the departments of corrections, education, public health, human services, public safety and human rights. This report and strategy was developed in consultation with the DPAC.