Simulation of Intrinsic Diffusion in Multicomponent Multiphase Systems

1998 ◽  
Vol 527 ◽  
Author(s):  
M. Hunkel ◽  
D. Bergner
Keyword(s):  
Single Phase ◽  
Diffusion Flux ◽  
Wind Effect ◽  
Concentration Profiles ◽  
Intrinsic Diffusion ◽  
Cross Terms ◽  
Multiphase Systems ◽  
Random Alloy ◽  
Simulation Results ◽  
Vacancy Flux

ABSTRACTA simulation model for intrinsic diffusion of multicomponent multiphase systems is presented. The model is not restricted onto a certain number of components or phases. For simplicity, Manning's random alloy model with vanishing vacancy wind effect is used. Then the cross terms of the diffusion flux can be neglected. The simulation routine uses equations for the fluxes, the equation of continuity and an equation for the change of the thickness of volume elements due to the vacancy flux. With this model diffusions paths, concentration profiles, fluxes of the components as well as marker positions can be calculated. The shift of interfaces and the growth of new phases can also be determined. The simulation results were compared with experimental data of the Cu-Fe-Ni system. Diffusion was studied in single-phase areas and across interfaces.

A Direction of Arrival Estimation Method for Wideband LFM Signals Based on RWT and ESPRIT Algorithm

2014 ◽  
Vol 1044-1045 ◽  
pp. 976-981
Author(s):  
Jian Zhong Xu ◽  
Fu Qiang Yu ◽  
Ping Guang Duan ◽  
Shu Hua Li
Keyword(s):  
Frequency Modulation ◽  
Estimation Method ◽  
Direction Of Arrival ◽  
Wigner Transform ◽  
Signal Parameter ◽  
Time Frequency ◽  
Cross Terms ◽  
Stationary Signals ◽  
Simulation Results ◽  
Esprit Algorithm

In this paper, we proposed a new algorithm to estimate the direction of arrival (DOA) for wideband linear frequency modulation (LFM) signals, using Radon-Wigner transform (RWT) and estimation of signal parameter via rotational invariance techniques (ESPRIT). To eliminate the cross-terms, we first utilize the RWT with its excellent time-frequency concentration performance. Then, through peak searching, the number of targets, the initial interference and the frequency modulation slope are estimated. On the this base, the array signals are reconstructed. Finally, we adopt the ESPRIT algorithm to estimate the DOA of the array signals. The simulation results show that the proposed algorithm can estimate the DOA of non-stationary signals with high precision.

Modeling and Simulation of Closed Loop Controlled Parallel Cascaded Buck Boost Converter Inverter Based Solar System

2015 ◽  
Vol 6 (3) ◽  
pp. 648 ◽  
Author(s):  
T. Sundar ◽  
S. Sankar
Keyword(s):  
Solar System ◽  
Modeling And Simulation ◽  
Single Phase ◽  
Closed Loop ◽  
Boost Converter ◽  
Open Loop ◽  
Boost Converters ◽  
Closed Loop Systems ◽  
Simulink Model ◽  
Simulation Results

<p>This Work deals with design, modeling and simulation of parallel cascaded buck boost converter inverter based closed loop controlled solar system. Two buck boost converters are cascaded in parallel to reduce the ripple in DC output. The DC from the solar cell is stepped up using boost converter. The output of the boost converter is converted to 50Hz AC using single phase full bridge inverter. The simulation results of open loop and closed loop systems are compared. This paper has presented a simulink model for closed loop controlled solar system.  Parallel cascaded buck boost converter is proposed for solar system.</p>

Simulation of No-Load Voltage of Single Phase Synchronous Generator Based on ANSYS

2011 ◽  
Vol 268-270 ◽  
pp. 231-234
Author(s):  
Jing Yang ◽  
Wei Jun Wang ◽  
Yong Gang Zuo ◽  
Ping Feng ◽  
Long Bo Mao
Keyword(s):  
Magnetic Field ◽  
Power Supply ◽  
Single Phase ◽  
Synchronous Generator ◽  
Simulation Method ◽  
Design Parameters ◽  
Test Results ◽  
Load Voltage ◽  
Simulation Results

The theory and method of analyzing the no-load magnetic field of single phase synchronous generator(SPSG) is presented in this article, and the no-load voltage of SPSG is simulated based on ANSYS program. The no-load voltage simulation results of a SPSG resemble its test results, which prove the simulation method in this article is correct and effective. The simulation results can provide theoretical bases and method for engineers in optimizing the design parameters to improve the power supply quality of SPSG.

Comparison of Switching Angle Arrangement Techniques in Single-Phase Boost Multilevel Inverter for Low-THD Operation

2015 ◽  
Vol 793 ◽  
pp. 167-171
Author(s):  
Mohd Aizuddin Yusof ◽  
Yee Chyan Tan ◽  
M. Othman ◽  
S.S. Lee ◽  
M.A. Roslan ◽  
...  
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Solar Photovoltaic ◽  
Voltage Waveform ◽  
Voltage Level ◽  
Software Simulation ◽  
Multilevel Inverters ◽  
Simulation Results

Multilevel inverters are one of the preferred inverter choices for solar photovoltaic (PV) applications. While these inverters are capable of producing AC staircase output voltage waveform, the total harmonic distortion (THD) of the output voltage waveform can become worse if the switching angle of each voltage level is not carefully chosen. In this paper, four switching angle arrangement techniques are presented and the switching angles generated by these techniques are applied to a new single-phase boost multilevel (SPBM) inverter. The performance of 3-, 5-, 7-, 9-and 11-level SPBM inverter having four different sets of switching angles derived using the aforementioned techniques have been evaluated and compared using PSIM software. Simulation results show that one of the techniques is able to produce an output voltage waveform with the lowest THD, whilst the other generates an output voltage waveform with the highest fundamental voltage component.

scholarly journals Reference Current Generation for Active Power Filtering in Single-Phase Power System

2021 ◽  
Vol 2120 (1) ◽  
pp. 012024
Author(s):  
Siew Ting Chew ◽  
Yap Hoon ◽  
Hafisoh Ahmad
Keyword(s):  
Steady State ◽  
Power System ◽  
Power Factor ◽  
Single Phase ◽  
Active Power ◽  
Dynamic State ◽  
Current Generation ◽  
Generation Algorithm ◽  
Reference Current Generation ◽  
Simulation Results

Abstract The study presents a new proposed reference current generation algorithm based on the synchronous reference frame (SRF) conventional algorithm in single-phase power system for an active power filtering. Shunt active power filter (SAPF) is often used as it can mitigate harmonic currents in the AC networks due to its superiority in dynamic-state conditions. The reference current generation algorithm is the most important control algorithms to control SAPF as it has the simplest implementation features. A proposed STF-based fundamental component identifier (STF-FCI) algorithm is implemented for the major improvements such as the removal of the unnecessary cosine function to reduce complexity of algorithm, employment of self-tuning filter (STF) to extract accurate fundamental component and to generate a sinusoidal reference current. The purpose of developing STF-FCI algorithm is to replace low pass filter (LPF) with a mean as it can generate a fast and accurate fundamental reference current to operate the SAPF in reducing the harmonics content of the power system and provide a fast response time in the dynamic-state conditions. This paper is presented under both steady-state which is capacitive (RC) load or inductive (RL) load as well as dynamic condition where capacitive load change to inductive load. The performance of steady-state condition will be evaluated in terms of THD values, ripple factor, power factor and phase difference. Under dynamic-state condition, the dynamic speed will be evaluated to capture the speed of the amplitude change in nonlinear load in a period of time. MATLAB-Simulink is used to design and evaluate the proposed STF-FCI algorithm with mean algorithm and LPF algorithm for comparison purpose. The simulation results had shown the major improvement when THD values, ripple factor, power factor and phase difference are reduced. The response time of the changing load is shorter by using mean algorithm compare to LPF algorithm. The simulation results obtained proved success when the proposed STF-FCI algorithm using mean algorithm are much better than LPF algorithm in steady-state and dynamic conditions under two voltage conditions i.e. ideal and distorted voltage.

scholarly journals Analysis and Design of Single-Phase Unidirectional Transducers with High Directivity

2021 ◽  
Vol 11 (16) ◽  
pp. 7500
Author(s):  
Xueping Sun ◽  
Shaobo Ge ◽  
Xiuting Shao ◽  
Shun Zhou ◽  
Wen Wang ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Insertion Loss ◽  
Single Phase ◽  
Center Frequency ◽  
The Finite Element Method ◽  
Analysis And Design ◽  
Saw Devices ◽  
Optimal Value ◽  
Simulation Results ◽  
The Relationship

Electrode-width-controlled (EWC) single-phase unidirectional transducers (SPUDT) contribute to reduction of insertion loss of surface acoustic wave (SAW) devices due to their strong unidirectional properties. In this work, we propose a method to optimize the unidirectionality of EWC-SPUDT based on our research results that the unidirectionality of the EWC-SPUDT cell is strongly related to its reflectivity and its unidirectional angle. Furthermore, in order to ensure strong unidirectionality to achieve low insertion loss, a simulator based on the finite element method (FEM) is used to study the relationship between geometrical configuration of the EWC-SPUDT cell and its reflection coefficient, as well as its transduction coefficient. Simulation results indicate that the reflection coefficient of the optimized EWC-SPUDT cell composed of 128° YX lithium niobite (LiNbO3) substrate and Al electrodes with thickness of 0.3μm reaches the optimal value of 5.17% when the unidirectional angle is designed to be −90°. A SAW delay line is developed with the optimized EWC-SPUDT cell without weighing, and the simulation results are verified by experiments. The experimental results show that the directivity exceeds 30 dB at the center frequency and the insertion loss is just 6.7 dB.

scholarly journals Performance Between PFC Cuk and Bridgeless PFC Cuk Converter with Various Output Voltages

2019 ◽  
Vol 8 (2S2) ◽  
pp. 41-46
Keyword(s):  
Low Power ◽  
Power Factor ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Input Current ◽  
Unity Power Factor ◽  
Cuk Converter ◽  
Maximum Current ◽  
Simulation Results ◽  
Power Application

This paper presents about the comparison between single-phase PFC Cuk converter and bridgeless PFC (BPFC) Cuk converter for low power application. This study attempts to investigate the characteristics of conventional and bridgeless PFC Cuk converter structures with three different output voltages and verified by the simulation results. The BPFC Cuk converter provides a lower Total Harmonic Distortion (THD) of input current than the conventional PFC Cuk converter. However, the conventional PFC Cuk converter has advantage of less maximum current stress at components compared to the BPFC Cuk converter. Conventional and BPFC Cuk converter can achieve an approximately unity power factor (PF).

scholarly journals Analysis of PM Magnetization Field Effects on the Unbalanced Magnetic Forces due to Rotor Eccentricity in BLDC Motors

2013 ◽  
Vol 3 (4) ◽  
pp. 461-466 ◽  
Author(s):  
S. Mahdiuon-Rad ◽  
S. R. Mousavi-Aghdam ◽  
M. Reza Feyzi ◽  
M. B. B. Sharifian
Keyword(s):  
Single Phase ◽  
Brushless Dc ◽  
Magnetic Forces ◽  
Field Effects ◽  
Field Patterns ◽  
Rotor Eccentricity ◽  
Simulation Results ◽  
Harmonic Components ◽  
Magnetization Field

This paper investigates both static and dynamic eccentricities in single phase brushless DC (BLDC) motors and analyzes the effect of the PM magnetization field on unbalanced magnetic forces acting on the rotor. Three common types of PM magnetization field patterns including radial, parallel and sinusoidal magnetizations are considered. In both static and dynamic eccentricities, harmonic components of the unbalanced magnetic forces on the rotor are extracted and analyzed. Based on simulation results, the magnetization fields that produce the lowest and highest unbalanced magnetic forces are determined in rotor eccentricity conditions.

scholarly journals Sensorless Control of a Fault Tolerant PMSM Drives in Case of Single-Phase Open Circuit Fault

2016 ◽  
Vol 7 (4) ◽  
pp. 1061
Author(s):  
Kamel Saleh ◽  
Mark Sumner
Keyword(s):  
Control Strategy ◽  
System Performance ◽  
Single Phase ◽  
Fault Tolerant ◽  
Sensorless Control ◽  
Fault Tolerant Control ◽  
Performance Degradation ◽  
Open Circuit ◽  
Phase Inverter ◽  
Simulation Results

This paper introduces a sensorless-speed-controlled PMSM motor fed by a four-leg inverter in case of a single phase open circuit fault regardless in which phase is the fault. To minimize the system performance degradation due to a single phase open circuit fault, a fault tolerant control strategy that includes taking appropriate actions to control the two remaining healthy currents is used in addition to use the fourth leg of the inverter.  Tracking the saliency is done through measuring the dynamic current responses of the healthy phases of the PMSM motor due the IGBT switching actions using the fundamental PWM method without introducing any modification to the operation of the fourth leg of the inverter. Simulation results are provided to verify the effectiveness of the proposed strategy for sensorless controlling of a PMSM motor driven by a fault-tolerant four-phase inverter over a wide speed ranges under the case of a single phase open circuit.

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