Composition Of Control System Research Articles

Reduced building energy consumption by combined indoor CO2 and H2O composition control

Rapid growth in global energy consumption has raised concern on the environmental impacts such as ozone layer depletion and climate change. Enclosed space, such as commercial buildings, accounts for about 40% of global energy consumption and the demand is constantly increasing due to increasing population, urbanization, and economic development. The energy demands in the building sector calls for strategic measures to develop energy efficient technologies. This paper presents a strategy to decrease energy demands inside buildings by proposing a ventilation system which regulates the enclosed air quality resulting in reduced air conditioning. The system consists of multiple adsorption beds with zeolite 13X monoliths for CO2 removal, and silica gel for humidity control, inside the enclosed space. The air conditioning system results in decrease in energy requirement and improvement in economics by 55% as compared with conventional ventilation system. The model is scaled up to the size comparable with total office inventory of New York City, and the reduction in carbon emissions by introducing the air composition control system for New York City is equivalent to replacing 57 million incandescent light bulbs by LEDs. This paper concludes that the air conditioning system proposed in this study results in the improvement in performance as compared to a conventional ventilation system and could reduce energy consumption inside commercial buildings.

Vapor Recompression C3 Splitter: Design and Control

Vapor recompression (VRC) based heat integration is usually employed for purifying a propylene-propane mixture in a C3 splitter. A fixed speed drive or a variable speed drive compressor may be employed for overhead vapor recompression. In this work, economic controllable designs for the two compressor types in a VRC C3 splitter are obtained via rigorous steady state and pressure driven closed loop dynamic simulations. A simple dual ended decentralized composition control system is shown to provide effective column regulation. The economic controllable design results indicate that when a fixed speed drive compressor is used, significant pressure drop must be provided across the compressor suction throttling valve for sufficient rangeability towards worst-case disturbance rejection. Accordingly, the column pressure and necessary compression ratio are higher for an overall more expensive process compared to a variable speed drive compressor. The case study highlights the importance for considering control at the conceptual design stage for designing a robust operable process.

Improvement of automatic control systems of high-power turbines of PAO tubroatom for nuclear power plants

The main technical solutions applied by PAO Turboatom used as the compensatory measures at the increase of the period of nonstop operation of nuclear power plants' (NPP) turbines with VVER-1000 type reactors up to 18 months are (1) replacing the standard hydraulic speed controller with an electronic one, (2) introduction of overclocking protection, (3) modernization of units of stop-control valves of high pressures, (4) installation of locking dampers on the receiver tubes of turbines of the first and second modification, and (5) improving the quality of repairs by reviewing the requirements for their implementation. The introduction of complex diagnostics of a control system on the basis of automatic treatment of results of registration of working parameters of the turbine is allocated as a separate prospective direction. Using an electronic controller of speed makes it possible to simplify the procedure of its inclusion in work at the failure of an electro-hydraulic system of control and vice versa. The regimes of maintaining the turbine rotor speed, steam pressure on the outlet of turbine, and the positions of main servomotors were introduced into the functions of the electronic controller. An electronic controller of speed includes its own electro-hydraulic transducer, turbine rotor speed sensor, and sensors of the position of main servomotors. Into the functions of electro- hydraulic control system and electronic speed controller, the function of overclocking protection, which determines the formation of commands for stopping the turbine at the exceeding of both the defined level of rotation speed and the defined combination of achieved rotation speed and angular acceleration of rotor, was introduced. To simplify the correction of forces acting on the control valve cups, the design of the cups was changed, and it has the profiled inserts. The solutions proposed were implemented on K-1100-60/1500-2M turbines of Rostov NPP. From the composition of control system of already made turbines, the devices of speed switching of moving of control flaps for opening and hydraulic damper in the servomotors of regulating flaps were excluded; the fists of the control valves providing the increased valve stroke for opening and the construction of filters for regulation, electro-hydraulic converters, oil draining device, etc. was changed.

Managing Interdependence in Multi-business Organizations

Managing interdependence in multi-business organizations is a profound challenge for the design and use of management control systems. Results of a case study of a leading multinational telecommunications provider suggest that the composition of control systems varies significantly with the type of interdependence. This is further substantiated by six qualitative sub-cases of the case study firm. Specifically, we find that management control systems are significantly more complex in cases of cooperative forms of interdependence than in cases of transactional forms. Contrary to expectations, this also applies to pooled interdependence which occurs when separate units share some common resources.

A Study on Low-Power Sensor Node based on Event-based Sampling Using Renewable Energy in Greenhouse

In the paper, we proposed low-power sensor node that applied to perform events-based sampling algorithm and to harvest energy through irrigation equipment applicable in greenhouse environment. The system composition to achieve such a goal could be divided into three parts of sensors, data processing and control, and this paper suggests a solution to an unnecessary wasting energy problem by using the event-based sampling to effectively reduce data exchange between the control system composition. Sensor node based on energy harvesting are implemented through micro-hydro generators connected to the irrigation equipment and it is confirmed that transmitting or receiving stable data is possible, reducing energy consumption of sensor node by the algorithm.

English

PID controllers are most popular controllers because of simplicity of implementation and broad applicability. In order to obtain the desired control performance correct tuning of PID controller is very important. There are many tuning algorithms available for tuning the PID controller. Most of the tuning processes are implemented manually. These processes are difficult and time consuming. Soft computing techniques have been widely used to tune the parameters of PID. In this paper parameters of PID controller are tuned using two sets of soft computing techniques which are Differential Evolution (DE) and Hybrid Differential Evolution (HDE). The optimal PID control parameters are applied for a composition control system. The performance of two techniques is evaluated by setting its objective function with Integral Square Error (ISE), Integral Absolute Error (IAE), Integral of Time multiplied by Absolute Error (ITAE). This paper also compares performance of tuned PID controller using DE and HDE methods with Ziegler-Nichols method.

Comparison of Control Methods of Permanent Magnet Synchronous Motor in Electric Vehicle

At present, the pure electric vehicles with a permanent magnet synchronous motor (PMSM) vector control (VC) and direct torque control (DTC) are mainly control method. These two kinds of control mode are considered as a high performance PMSM control strategy which has been widely used in practice [5]. Starting from the mathematical model of PMSM, two kinds of control strategies are to be the theoretical analysis, so that the control thoughts and the composition of control system has a profound understanding to applies two kinds of strategies to control of PMSM. Simulink modeling and simulation results proved that vector control is better than that of direct torque.

05/01890 Research on the influence of air humidity on theannual heating or cooling energy consumption: Long, E. et al. Building and Environment, 2005, 40, (4), 571–578

Rapid growth in global energy consumption has raised concern on the environmental impacts such as ozone layer depletion and climate change. Enclosed space, such as commercial buildings, accounts for about 40% of global energy consumption and the demand is constantly increasing due to increasing population, urbanization, and economic development. The energy demands in the building sector calls for strategic measures to develop energy efficient technologies. This paper presents a strategy to decrease energy demands inside buildings by proposing a ventilation system which regulates the enclosed air quality resulting in reduced air conditioning. The system consists of multiple adsorption beds with zeolite 13X monoliths for CO2 removal, and silica gel for humidity control, inside the enclosed space. The air conditioning system results in decrease in energy requirement and improvement in economics by 55% as compared with conventional ventilation system. The model is scaled up to the size comparable with total office inventory of New York City, and the reduction in carbon emissions by introducing the air composition control system for New York City is equivalent to replacing 57 million incandescent light bulbs by LEDs. This paper concludes that the air conditioning system proposed in this study results in the improvement in performance as compared to a conventional ventilation system and could reduce energy consumption inside commercial buildings.

Developments in the fabrication and performance of high-quality HgCdTe detectors grown on 4-in. Si substrates

We are continuing to develop our growth and processing capabilities for HgCdTe grown on 4-in. Si substrates by molecular beam epitaxy (MBE). Both short-wave and mid-wave infrared (SWIR and MWIR) double-layer hetero-junctions (DLHJs) have been fabricated. In order to improve the producibility of the material, we have implemented an in-situ growth composition-control system. We have explored dry etching the HgCdTe/Si wafers and seen promising results. No induced damage was observed in these samples. Detector results show that the HgCdTe/Si devices are state-of-the-art, following the diffusion-limited trend line established by other HgCdTe technologies. Focal-plane array (FPA) testing has been performed in order to assess the material over large areas. The FPA configurations range from 128 × 128 to 1,024 × 1,024, with unit cells as small as 20 µm. The MWIR responsivity and NEDT values are comparable to those of existing InSb FPAs. Pixel operabilities well in excess of 99% have been measured. We have also explored the role of growth macrodefects on diode performance and related their impact to FPA operability. The SWIR HgCdTe/Si shows similar results to the MWIR material. Short-wave IR FPA, median dark-current values of less than 0.1 e-/sec have been achieved.

Operating an ideal heat integrated distillation column with different control algorithms

The operation of an ideal heat integrated distillation column is addressed. Five control strategies, namely, single loop composition control system, multi-loop composition control system, multivariable internal model control (IMC) system, modified multivariable IMC control (MIMC) system and nonlinear process model based control (NPMC) system, are design and applied to the process. Simulation results demonstrate that all the control systems are capable of keeping both end products on their specifications. The NPMC is the best one in the operation of the ideal HIDiC. It can very smoothly realize setpoint transition and efficiently counteract external disturbances. The MIMC ranks the second for the regulatory responses to feed composition disturbances have relative longer setting time. The next comes to the multi-loop composition control system. Although it works well for the operation of the ideal HIDiC, it produces relative larger oscillations and longer setting time in the system responses. The IMC can not compete with the multi-loop composition control system because it is extremely sensitive to operating condition changes. The single-loop composition control system is the worst one for the responses of the uncontrolled product is extremely sluggish.

Polymerization of olefins through heterogeneous catalysis. XVI. Design and control of a laboratory stirred bed copolymerization reactor

A novel lab-scale stirred bed gas phase reactor system has been designed and constructed for investigating the kinetic behaviour of olefin copolymerization reactions using heterogeneous catalysts. The system, equipped for basic temperature and pressure control, also includes an on-line composition control system which maintains close control of reactor composition for gaseous and liquid monomers as well as for hydrogen. With this apparatus, it is now possible to investigate the fundamental kinetic features of the catalyst system with high precision. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 373–382, 1997

Automatic Control of Micropropagation Medium Sucrose Concentration

A whole plant liquid/membrane micropropagation bioreactor system was modified to allow the culture process to operate semicontinuously. The medium composition control (MCC) system allowed bioreactor medium to be sampled automatically at 3-h intervals and an aliquot analyzed for sucrose and dextrose concentration. Data obtained were used as the input to a three-state on/off control system which maintained medium sucrose within a preset threshold of 5% of the desired concentration and medium volume levels within a 2.5% threshold. The MCC system performance testing, without explant tissue, showed it to respond within these design limits when disturbances and setpoint changes were imposed on the system. Stage 1 Nicotiana tabacum (tobacco) explants cultured in the MCC system were found to have both large fresh weight gains and prolific shoot production. The MCC-grown explants showed increased tissue fresh weight gains over previous bioreactor studies including treatments on conventional agar-based medium, on static-liquid medium, in a liquid/membrane bioreactor with seven-day fresh medium replacement and in a liquid/membrane bioreactor equipped for monitoring sucrose concentrations.

Natural language interface for fault diagnosis system of nuclear power plant control systems.

A fault diagnosis system was developed to improve the availability and maintainability of control systems in nuclear power plants. To facilitate man-machine communications in the system a natural language interface was introduced. Features of the interface include two-step analysis of the meaning of input sentences, identification of the kind of input content using sentence patterns, and retrieval of the information required. For the information retrieval, when information is lacking supplementation is done by referring to the dialog history and knowledge of the control system composition. Dialog tests, including the required information inputs for diagnosis and questions about the validity of the diagnosis results, were performed by the control system simulator for an assumed component failure, such as a printed circuit board failure. Dialog inputs were made by voice and outputs were by voice or a CRT display. The tests confirmed that inputs required in the diagnosis process can be entered by voice witho...

Composition control for evaporated CoCr thin films

Composition control was achieved in fabrication of CoCr thin films by evaporation onto tape-shaped polymer substrates. The vapor composition during deposition was determined by an atomic absorption type of detectors and a composition calculator. The gradual change of composition during deposition due to the difference in vapor pressure between Co and Cr was compensated by supplying Cr into the evaporator. As a result, the desirable composition was obtained to within an accuracy of 0.4 wt.%. This composition control system was shown to be suitable for the preparation of CoCr perpendicular magnetic recording media.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Preliminary experience with a configuration control system for modular programs

This paper describes some preliminary experience gathered during the implementation and early use of a program composition and version control system. This system has been designed and implemented as a part of the Adele research project, a programming environment for the production of modular programs (Estublier 83). This project has four main components: a) a program editor, interpreter and debugger; b) a parameterized code generator; c) a user interface; d) a program base, the subject of this paper. The current version of this environment has been developed on a Multics system. The program base, including the system composition and version control mechanisms, has been used for six months, notably for its own development and maintenance.

Preliminary experience with a configuration control system for modular programs

This paper describes some preliminary experience gathered during the implementation and early use of a program composition and version control system. This system has been designed and implemented as a part of the Adele research project, a programming environment for the production of modular programs (Estublier 83). This project has four main components: a) a program editor, interpreter and debugger; b) a parameterized code generator; c) a user interface; d) a program base, the subject of this paper. The current version of this environment has been developed on a Multics system. The program base, including the system composition and version control mechanisms, has been used for six months, notably for its own development and maintenance.

A Microprocessor-Based Adaptive Composition Control System

A general multivariable model of the mill-silo system is given. A general multivariable adaptive control system is described. Using a special linearizing and decoupling possibility single variable adaptive control loops are then introduced. Finally the applied μP system and practical results are presented.