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The paper deals with an emerging problem of AC to DC power converters: the establishment of the mean value of the rectified voltage. This is a difficult task due to the nonlinear behavior of the capacitor filter, attached to the rectifiers. Are proposed novel, simplified mathematical models both of the controlled and uncontrolled rectifier, useful in analysis and design stage. A software product is...
The use of fractional operators in automatic control theory is in fact an old concept but also represents a new research field due to the development of effective computational tools. Adaptive controllers and fractional order controllers have been introduced in to order improve the performances and the robustness of the control system. In this study the model reference adaptive control is extended...
Research in the domain of renewable sources of electricity is in continuous grow. The direct conversion of the Sun power in electricity is a promising possibility using the photoelectric industrial panels. In order to estimate the performance of the photovoltaic panels or to design a proper control system, a mathematical of the panel is needed. The used conventional models are “physical” models, each...
The paper presents a novel, original control strategy in order to increase the efficiency of the renewable energy systems. The proposed algorithm uses the Extremum System framework, continuously adjusting the manipulated variable in order to maintain the output as near as possible to its extreme value. The maximum point seeking algorithm is an original, simple one, based on the analysis of the slope...
Cryogenic isotope separation column cascade is complex equipment, with special control challenges. One of the main manipulated variables in these plants is the value of the instantaneous electrical power transferred to the heating resistor in the subsystem called boiler. In order to avoid any electromagnetic interference between various sensors attached to each column, the heating resistors must be...
One of the main elements of a cryogenic (13C) separation column is the boiler. The control of the power supply which feeds the boiler's resistance is of major importance. In order to ensure a safe and stable operation of the plant, a monitoring and control unit is designed using NI PXI-8183 process computer. The developed LabVIEW™ application implements a PI controller and also data logging. Step...
The (13C) isotope separation column is a complex process with many inputs and outputs. Proper literature is scarce (or inexistent) due to the fact that only a few plants exist in the world and due to data protection issues. In order to design an advanced control strategy, implemented on a process computer in LabVIEW™, in the present work was developed a mathematical model, described by a transfer...
In the petrochemical technological processes, the synthesis of 2 ethyl-hexanol-oxo-alcohol is of highest importance, being achieved through catalytic hydrogenation of 2 ethyl-hexenal. The hydrogenation reaction is highly exothermic so the reactor output temperature may become critical. The paper models the complex process of these chemical reactions and proposes and designs a new control system structure...
This paper is a step forward by making real time control system design to monitor and control process variables to ensure its smooth operation and desired reliability. Liquid nitrogen level in the condenser is a core component of isotopic separation process to obtain (13C), so is needed a special focus on monitoring and control. The goal of the work is to design a controller for the liquid nitrogen...
Actual computer based process simulations are recognized as essential tool in chemical process. The aim of this paper is to develop a mathematical model that describes the chemical processes that occur in a reactor used for hydrogenation of 2-ethyl-hexenal to 2-ethyl-hexanol. The developed model is based on the mass balance and reaction kinetics equations. The equations include both ordinary differential...
The problem of the ion separation/detection has applications in many fields, like: nuclear technology, detection of contraband and explosives, security and military domain. In weak electric fields, the ratio (K) of the ion speed (v) over electric field strengths (E) is typical for each ion with the given mass (m) and electrical charge (e). This ratio, known as mobility (K), can be measured using the...
Huge quantities of clean energy can be obtained from the waves of the oceans and seas. As wave energy extraction technology is currently in a preliminary state of development any new results in this field should be of real interest. A direct driven wave power conversion system to be placed in the Black Sea near the Romania shores was proposed and analyzed. The paper focuses on its linear generator,...
The industrial distillation plants-like those for crude oil- and the cryogenic distillation column for (13C) isotope enrichment have in common the probability to appear an undesirable phenomenon: the flooding, when the plant efficiency decreases drastically. After a general description of the isotope separation problem, the paper describes the column mode of operation and gives the mathematical equations,...
The applications of stable isotopes from different chemical elements are well-known. Based on specific properties, a great diversity of isotope concentration (separation) methods have been developed, one of them being the cryogenic separation for (13C). After a short description of the separation equipment (separation column), the authors deal with the arising of the flooding process. Based on simplified...
To reduce the emission by Diesel-engine in railway traction, continuous development and innovation in combustion, sensing net, control method and strategies are required to met the legal requirements. Multiple combustion modes by Diesel engines can reduce significantly the emissions and maintain the functionality of the exhaust treatment systems by simultaneous achievement of the desired torque-speed...
In the railway traction systems, an important role play diesel-electric locomotive. The AC traction motor proves its advantages compared to the DC older motor, but the supply (the power inverter) is more sophisticated and expensive and, in many cases, not too safe. The authors propose for diesel-electric locomotive a different version of supplying system, based on amplitude modulation and cheap and...
The actual paper deals with the general problem of the water purification with the aim to be accepted as potable water, using two physical methods: in the first stage, the ozone-treatment and then, the ultraviolet (UV) radiation treatment in water transport pipes. A higher treatment efficiency is achieved by superposition of both methods: higher reaction rate, smaller ozone dose and UV-radiation times...
The chemical processes developed in the 13C-isotope separation plant are very complex and many details are not yet known in totality. The authors are concerned with the problem of developing effective and readily implemental techniques for modelling and control of the isotope separation plant. In the present paper are presented a variant of model predictive control (MPC) of the isotope separation...
The modern food industry requires high quality processing water at greater flow rate. The actual paper presents an original computer controlled pilot equipment in multiple stages: fresh air treatment in the underground pipe, treatment in pulsating electric filed, water softening in electromagnetic field and the disinfection in ultraviolet (UV) ray. The high-level water purification is ensured in two...
The (13C) isotope separation process is a very important technical, scientific and industrial domain of activity. The operation plant is complex, with many input-output variables, difficult to model and to control. The authors identify the terminal and internal variable, define a dedicated structural model and conceive a complex control system, able to maintain the separation process at the desired...
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