scholarly journals METHOD MANY-PARAMETRIC FUNCTIONS FOR ANALYSIS OF THE CONNECTING PROCESSES IN ELECTRIC CIRCUIT WITH SEMICONDUCTOR COMMUTATORS

2020 ◽  
Vol 0 (1(151)) ◽  
pp. 63-69
Author(s):  
Vladislav Mikhailenko
Keyword(s):  
Electric Circuit ◽  
Parametric Functions

Automation of Two-Stage Factor VIII Assay

1978 ◽  
Vol 39 (02) ◽  
pp. 455-465 ◽  
Author(s):  
Yvonne Stirling ◽  
D J Howarth ◽  
Marguerite Vickers ◽  
W R S North ◽  
T W Meade
Keyword(s):  
Factor Viii ◽  
Optical Density ◽  
Electric Circuit ◽  
Clotting Time ◽  
Two Stage ◽  
Laboratory Error ◽  
Premature Closure ◽  
Factor Viii Concentrates ◽  
Experimental Findings ◽  
Automated Methods

SummaryTwo automated methods for two-stage factor VIII assays have been compared with one another, and evaluated in practice. The Depex method records the clotting time when an electric circuit is completed by the formation of a fibrin thread across a hook-type electrode; the Electra method is based on an optical density technique of clot detection. The two methods gave comparable results for measured levels of factor VIII when haemophilic or “normal” plasmas were assayed. Results from the two methods in practice also suggest that both are valid at low and “normal” factor VIII levels. The Electra method is also probably suitable for assays of concentrates; however, the Depex method appears to give falsely high values in these circumstances, and experimental findings suggest that the reason may be that increased viscosity due to the high fibrinogen levels in factor VIII concentrates causes premature closure of the circuit between the two ends of the Depex electrode. The main advantage of the Depex method is that, provided 3 or 4 machines are available, a given number of assays can be completed more quickly than on Electra. The main advantages of Electra are that it is probably subject to less laboratory error than Depex, and that it is suitable for assaying concentrates as well as haemophilic and “normal” plasmas.

Thin-film magnetoresistive current sensors

2019 ◽  
pp. 59-64
Author(s):  
V. I. Sukhanov ◽  
A. B. Grabov
Keyword(s):  
Thin Film ◽  
Electric Circuit ◽  
Current Control ◽  
Electronic Apparatus ◽  
Current Sensors

The article presents some features of thin-film magnetoresistive current sensors and detectors that was developed in JSC NPO IT for noncontact current control in electric circuit aviation and cosmic electronic apparatus.

МАКРОМОДЕЛИРОВАНИЕ СХЕМЫ ФАПЧ С ИСПОЛЬЗОВАНИЕМ ПОЛНОЙ ПРИНЦИПИАЛЬНОЙ СХЕМЫ ФАЗОВОГО ДЕТЕКТОРА

2020 ◽  
Vol 96 (3s) ◽  
pp. 295-299
Author(s):  
М.М. Гурарий ◽  
М.М. Жаров ◽  
Л.П. Ионов ◽  
И.И. Мухин ◽  
С.Г. Русаков ◽  
...  
Keyword(s):  
Electric Circuit ◽  
Schematic Diagram ◽  
Equivalent Electric Circuit ◽  
Phase Frequency Detector ◽  
Frequency Detector ◽  
A Current

В работе рассмотрены проблемы анализа схем ФАПЧ с учетом наличия неидеальностей в схеме частотно-фазового детектора с токовым ключом. Для снижения затрат на моделирование предложено использовать эквивалентную электрическую схему, содержащую полную принципиальную схему ЧФД и схемные эквиваленты макромоделей остальных блоков ФАПЧ. The paper considers the problems of analyzing the PLL circuit taking into account the presence of nonidealities in the phase-frequency detector with a current key. To reduce the simulation efforts, it has been proposed to apply an equivalent electric circuit containing the complete schematic diagram of the PFD and circuit equivalents of the macromodels of other PLL blocks.

Two-Phase Short Circuit in the Power Grid Powered by a Transformer with a Y/Δ-11 Winding Connection

2020 ◽  
pp. 25-30
Author(s):  
Aleksandr S. Serebryakov ◽  
Vladimir L. Osokin ◽  
Sergey A. Kapustkin
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Relay Protection ◽  
Electric Circuit ◽  
Operational Reliability ◽  
Research Purpose ◽  
Industrial Complex ◽  
Two Phase ◽  
Short Circuit Currents ◽  
Secondary Winding

The article describes main provisions and relations for calculating short-circuit currents and phase currents in a three-phase traction transformer with a star-triangle-11 connection of windings, which feeds two single-phase loads in AC traction networks with a nominal voltage of 25 kilovolts. These transformers provide power to the enterprises of the agro-industrial complex located along the railway line. (Research purpose) The research purpose is in substantiating theoretical equations for digital intelligent relay protection in two-phase short circuits. (Materials and methods) It was found that since the sum of instantaneous currents in each phase is zero, each phase of the transformer works independently. We found that this significantly simplifies the task of analyzing processes with a two-phase short circuit. In this case, the problem of calculating short-circuit currents in the traction network can be simplified by reducing it to the calculation of an ordinary electric circuit with three unknown currents. (Results and discussion) The article describes equations for calculating short-circuit resistances for one phase of the transformer when connecting the secondary winding as a star or a triangle. The currents in the phases of the transformer winding at short circuit for the star-triangle-11 and star-star-with-ground schemes are compared. It was found that when calculating short-circuit currents, there is no need to convert the secondary winding of the traction transformer from a triangle to a star. (Conclusions) It was found that the results of the research can be used in the transition of relay protection systems from electromagnetic relays to modern high-speed digital devices, which will increase the operational reliability of power supply systems for traction and non-traction power consumers.

scholarly journals Time-Domain Analysis of Fractional Electrical Circuit Containing Two Ladder Elements

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 475
Author(s):  
Ewa Piotrowska ◽  
Krzysztof Rogowski
Keyword(s):  
Fractional Derivative ◽  
Fractional Derivatives ◽  
Electric Circuit ◽  
Theoretical Models ◽  
Time Domain Analysis ◽  
Electrical Circuit ◽  
State Variable ◽  
State Space System ◽  
Derivatives Of ◽  
Different Order

The paper is devoted to the theoretical and experimental analysis of an electric circuit consisting of two elements that are described by fractional derivatives of different orders. These elements are designed and performed as RC ladders with properly selected values of resistances and capacitances. Different orders of differentiation lead to the state-space system model, in which each state variable has a different order of fractional derivative. Solutions for such models are presented for three cases of derivative operators: Classical (first-order differentiation), Caputo definition, and Conformable Fractional Derivative (CFD). Using theoretical models, the step responses of the fractional electrical circuit were computed and compared with the measurements of a real electrical system.

Dynamic Simulation Studies of Performed Additional Tests During FAT for Emergency Diesel Generators at Nuclear Power Plant

2016 ◽  
Author(s):  
Salah K. Kanaan ◽  
Amer Omanovic
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Electric Circuit ◽  
Diesel Generator ◽  
Safety Regulations ◽  
Auxiliary Power ◽  
Current Voltage ◽  
Measurement Results ◽  
Generator Sets

In 2004, a decision was made to perform a modernization and a new power uprate of unit 2 at Oskarshamn nuclear power plant in Sweden. Among the most important reasons for this decision were new safety regulations from Swedish Radiation Safety Authority and ageing of important components. A project was established and became the largest nuclear power modernization in the world. The modernization led to the need of analysing the auxiliary power system to ensure that it could supply the unit after the uprate, given tolerances on current, voltage and frequency. During the process of developing models for the diesel generator sets, it turned out that the suppliers could not deliver enough satisfactory material for modelling the diesel engines, the speed controllers and the magnetization systems. Therefore, Oskarshamn nuclear power plant with the help of the manufacturers of the diesel generator sets carried out additional measurements in order to collect data for modelling. Based on electric circuit diagrams provided by the manufacturers, block diagrams of the magnetization systems were made. For the speed controllers, no information was available at all so it was assumed that the controller was of PI-type. The parameters of the magnetization systems and the speed controllers were then tuned using the measurement results. Finally, a comparison between simulated results and the measurement results were made, showing good agreement. This is especially true in the most commonly used operating interval of the diesel generator sets.

scholarly journals A New Approach for Approximate Solution of ADE: Physical-Based Modeling of Carriers in Doping Region

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 458
Author(s):  
Leobardo Hernandez-Gonzalez ◽  
Jazmin Ramirez-Hernandez ◽  
Oswaldo Ulises Juarez-Sandoval ◽  
Miguel Angel Olivares-Robles ◽  
Ramon Blanco Sanchez ◽  
...  
Keyword(s):  
Differential Equation ◽  
Approximate Solution ◽  
Analytic Solution ◽  
Order Differential Equation ◽  
Electric Circuit ◽  
New Approach ◽  
In Doping ◽  
Electric Behavior ◽  
Spatio Temporal ◽  
Physical Phenomena

The electric behavior in semiconductor devices is the result of the electric carriers’ injection and evacuation in the low doping region, N-. The carrier’s dynamic is determined by the ambipolar diffusion equation (ADE), which involves the main physical phenomena in the low doping region. The ADE does not have a direct analytic solution since it is a spatio-temporal second-order differential equation. The numerical solution is the most used, but is inadequate to be integrated into commercial electric circuit simulators. In this paper, an empiric approximation is proposed as the solution of the ADE. The proposed solution was validated using the final equations that were implemented in a simulator; the results were compared with the experimental results in each phase, obtaining a similarity in the current waveforms. Finally, an advantage of the proposed methodology is that the final expressions obtained can be easily implemented in commercial simulators.

On Thick-Walled Cylinder Under Internal Pressure

2003 ◽  
Vol 125 (3) ◽  
pp. 267-273 ◽  
Author(s):  
W. Zhao ◽  
R. Seshadri ◽  
R. N. Dubey
Keyword(s):  
Internal Pressure ◽  
Strain Curve ◽  
Stress Strain ◽  
Piecewise Linearization ◽  
Elastic Plastic ◽  
Plastic Cylinder ◽  
Parametric Functions ◽  
The Difference ◽  
New Formulation ◽  
Walled Cylinder

A technique for elastic-plastic analysis of a thick-walled elastic-plastic cylinder under internal pressure is proposed. It involves two parametric functions and piecewise linearization of the stress-strain curve. A deformation type of relationship is combined with Hooke’s law in such a way that stress-strain law has the same form in all linear segments, but each segment involves different material parameters. Elastic values are used to describe elastic part of deformation during loading and also during unloading. The technique involves the use of deformed geometry to satisfy the boundary and other relevant conditions. The value of strain energy required for deformation is found to depend on whether initial or final geometry is used to satisfy the boundary conditions. In the case of low work-hardening solid, the difference is significant and cannot be ignored. As well, it is shown that the new formulation is appropriate for elastic-plastic fracture calculations.

Sign in / Sign up

Export Citation Format

Share Document