scholarly journals To the Phenomenological theory of Avalanche-Like Effect in Dc-Biased Microwave Nonlinear HTS Transmission Line

2019 ◽  
Vol 64 (10) ◽  
pp. 962 ◽  
Author(s):  
S. I. Melnyk ◽  
S. S. Melnyk ◽  
A. A. Lavrinovich ◽  
M. T. Cherpak
Keyword(s):  
Transmission Line ◽  
Direct Current ◽  
Phenomenological Model ◽  
Phenomenological Theory ◽  
Mathematical Apparatus ◽  
Proposed Model ◽  
Fold Type ◽  
Microwave Losses ◽  
Dissipative State

A phenomenological model has been proposed to describe the avalanche-like transition of a microwave nonlinear HTSC-based transmission line into a dissipative state. This effect was observed by the authors in a dc-biased transmission line. The proposed model generalizes the well-known phenomenological model for the nonlinear HTSC-based transmission line under the action of a direct current. The character of the dependences obtained for microwave losses allows the jump-like changes in the properties of the nonlinear HTSC-based transmission line to be regarded as a fold-type catastrophe and the methodological and mathematical apparatus of the theory of catastrophes to be used in order to explain the results obtained and predict new ones.

scholarly journals Direct-current-assisted microwave quenching of YBa2Cu3O7−δ coplanar waveguide to a highly dissipative state

2014 ◽  
Vol 105 (2) ◽  
pp. 022601 ◽  
Author(s):  
N. T. Cherpak ◽  
A. A. Lavrinovich ◽  
A. I. Gubin ◽  
S. A. Vitusevich
Keyword(s):  
Direct Current ◽  
Coplanar Waveguide ◽  
Dissipative State

A phenomenological model for thermally-induced hysteresis in polycrystalline shape memory alloys with internal loops

2021 ◽  
pp. 1045389X2110482
Author(s):  
Yuxiang Han ◽  
Haoyuan Du ◽  
Linxiang Wang ◽  
Roderick Melnik
Keyword(s):  
Shape Memory Alloys ◽  
Single Crystal ◽  
Shape Memory ◽  
Phenomenological Model ◽  
Landau Theory ◽  
Thermally Induced ◽  
First Order ◽  
Proposed Model ◽  
Crystal Model ◽  
Hysteretic Response

In the current study, a 1-D phenomenological model is constructed to capture the temperature-induced hysteretic response in polycrystalline shape memory alloys (SMAs). The martensitic and austenitic transformations are regarded as the first-order transitions. A differential single-crystal model is formulated on the basis of Landau theory. It is assumed that the transformation temperatures follow the normal distribution among the grains due to the anisotropic stress field developed in the material. The polycrystalline hysteretic response is expressed as the integration of single-crystal responses. Besides, the prediction strategy for incomplete transitions is presented, and the first-order reversal curves are obtained via density reassignment. The proposed model is numerically implemented for validation. Comparisons between the modeling results and the experimental ones demonstrate the capability of the proposed model in addressing the hysteresis in thermally-induced phase transformations.

scholarly journals Design Analysis of a Dual Rotor Permanent Magnet Machine driven Electric Vehicle

2018 ◽  
Vol 152 ◽  
pp. 03004
Author(s):  
Mohd Izzat Bin Zainuddin ◽  
CV Aravind
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Direct Current ◽  
Load Condition ◽  
Magnetic Flux Density ◽  
Torque Density ◽  
Proposed Model ◽  
Outer Rotor ◽  
Electric Bike

Electric bike in urban countries such as Europe and China commonly used the brushless direct current machine (BLDC) as it able to produce high torque to transport the user from one place to another. However, BLDC torque density can’t be improving due to limitation magnetic flux generated by the permanent magnet. Therefore, the performance of electric bike can’t be improved. Outer rotor BLDC machine design able to improve the torque density of the motor due to increase radius of the motor which can be explained by simple physics equation (Torque = Force x radius). However, an outer rotor machine only generates constant speed, which is not suitable for operating under tractive load condition, especially electric bike. The proposed model is a new novel of double layer outer rotor BLDCPM machine which able to amplify the magnetic flux density and improve the torque density of the machine. The mutual magnetic coupling between the inner and outer rotor of the proposed model increase the magnetic flux intensity as both of them acts as individual parts. Thus, the magnetic flux generated by both rotors are double which resulted in improving the performance of the E-bike. Designing parameters and analysing the performance of the proposed 2D model is done using FEA tools. Evaluation of the conventional and proposed model by comparing torque performance, magnetic flux density and motor constant square density. Other than that, speed torque graph also is evaluated to justify either it can operate similarly to ICE engine with gears. Two model is designed which is Single Outer Rotor Brushless Direct Current (SORBLDC) and Double Outer Rotor Brushless Direct Current (DORBLDC) operated with the same cases of 27 Amp current supplied to it and operate under various speed from 500 rpm to 2000 rpm. The average torque produce by the conventional and proposed model are 2.045439 Nm and 3.102648 Nm. Furthermore, improvement of the proposed model to conventional model in terms of motor constant square density by 24.92%. Therefore, the proposed model able to improve the magnetic flux by amplifying which resulted to increase the torque density of the machine. Furthermore, the speed-torque graph of the proposed machine shows similarity with speed torque graph of ICE engine. Thus, the proposed machine is suitable to operate for bike application

scholarly journals Research on Virtual Inductive Control Strategy for Direct Current Microgrid with Constant Power Loads

2019 ◽  
Vol 9 (20) ◽  
pp. 4449 ◽  
Author(s):  
Zhiping Cheng ◽  
Meng Gong ◽  
Jinfeng Gao ◽  
Zhongwen Li ◽  
Jikai Si
Keyword(s):  
Transmission Line ◽  
Direct Current ◽  
Control Strategy ◽  
Control Method ◽  
Control Strategies ◽  
Performance Comparison ◽  
Distributed Resources ◽  
Constant Power ◽  
Dc Microgrid ◽  
Constant Power Loads

In order to improve the stability of direct current (DC) microgrid with constant power loads, a novel virtual inductive approach is proposed in this paper. It is known that the negative impedance characteristic of constant power loads will lead to DC bus voltage fluctuation, which will be more serious when they integrate into the DC microgrid though a large transmission line inductive. For the convenience of analysis, a simplified circuit model of the system is obtained by modeling the distributed resources. Unlike the existing control strategies, the proposed control strategy constructs a negative inductance link, which helps to counteract the negative effects of the line inductive between the power source and the transmission line. Detailed performance comparison of the proposed control and virtual capacitance are implemented through MATLAB/simulink simulation. Moreover, the improved performance of the proposed control method has been further validated with several detailed studies. The results demonstrate the feasibility and superiority of the proposed strategy.

Modeling and System Identification of Hemodynamic Responses to Vasopressor-Inotropes

2013 ◽  
Author(s):  
Ramin Bighamian ◽  
Sadaf Soleymani ◽  
Andrew T. Reisner ◽  
Istvan Seri ◽  
Jin-Oh Hahn
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Phenomenological Model ◽  
Peripheral Resistance ◽  
Initial Step ◽  
Automated Control ◽  
Cardiovascular Parameters ◽  
Response Data ◽  
Proposed Model ◽  
Epinephrine Dose

In an effort to establish an initial step towards the ultimate goal of developing an analytic tool to optimize the vasopressor-inotrope therapy through individualized dose-response relationships, we propose a phenomenological model intended to reproduce the hemodynamic response to vasopressor-inotropes. The proposed model consists of a cardiovascular model relating blood pressure to cardinal cardiovascular parameters (stroke volume and total peripheral resistance) and the phenomenological relationships between the cardinal cardiovascular parameters and the vasopressor-inotrope dose, in such a way that the model can be adapted to individual patient solely based upon blood pressure and heart rate responses to medication dosing. In this paper, the preliminary validity of the proposed model is shown using the experimental epinephrine dose versus blood pressure and heart rate response data collected from five newborn piglets. Its performance and potential usefulness are discussed. It is anticipated that, potentially, the proposed phenomenological model may offer a meaningful first step towards the automated control of vasopressor-inotrope therapy.

scholarly journals Simplified Vibration Model and analysis of a single-conductor transmission line with dampers

2016 ◽  
Vol 231 (22) ◽  
pp. 4150-4162 ◽  
Author(s):  
O Barry ◽  
R Long ◽  
DCD Oguamanam
Keyword(s):  
Transmission Line ◽  
Equations Of Motion ◽  
Frequency Equation ◽  
Mode Shapes ◽  
Viscous Damping ◽  
Equivalent Viscous Damping ◽  
Proposed Model ◽  
Vibration Model ◽  
Mass Spring ◽  
Discrete Mass

A novel model is developed for a vibrating single-conductor transmission line carrying Stockbridge dampers. Experiments are performed to determine the equivalent viscous damping of the damper. This damper is then reduced to an equivalent discrete mass-spring-mass and viscous damping system. The equations of motion of the model are derived using Hamilton’s principle and explicit expressions are determined for the frequency equation, and mode shapes. The proposed model is verified using experimental and finite element results from the literature. This proposed model excellently captures free vibration characteristics of the system and the vibration level of the conductor, but performs poorly in regard to the vibration of the counterweights.

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