On the Wave Propagation of Disturbances in Homogeneous Electromechanical Systems

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Kalyan Dasgupta ◽  
Anil M. Kulkarni ◽  
S. A. Soman
Keyword(s):  
Wave Propagation ◽  
Power Systems ◽  
Transport Delay ◽  
System Parameters ◽  
Mass Line ◽  
Lumped Parameter ◽  
Mechanical Waves ◽  
Nonhomogeneous System ◽  
Velocity Of Propagation ◽  
Line Resistance

In this paper, we make an attempt to describe the phenomenon of wave propagation when a disturbance is introduced in an electromechanical system having a lumped parameter representation. We initially discuss mechanical waves in homogeneous spring mass systems and then focus on electromechanical wave propagation in power systems. We primarily discuss ring and open end systems. Eigenvalue analysis of the system is done to find the behavior of the orthogonal modes as a function of time and space. We then derive an expression for velocity of propagation of the disturbance wave and the transport delay associated with it. Effects of system parameters, like generator inertia and transmission line resistance, are also discussed. Although the theory was developed considering homogeneous systems (identical values of inertia/mass, line parameters/spring constant, etc.), an implementation on a nonhomogeneous system is also presented in this paper. Numerical simulations were done and compared with the analytical results derived in this paper.

Studying Electromechanical Wave Propagation and Transport Delays in Power Systems

2013 ◽  
Vol 14 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Kalyan Dasgupta ◽  
A.M. Kulkarni ◽  
Shreevardhan Soman
Keyword(s):  
Wave Propagation ◽  
Power Systems ◽  
Power System ◽  
Orthogonal Decomposition ◽  
Electromechanical System ◽  
Sensitivity Matrix ◽  
Transport Delay ◽  
Velocity Of Propagation

Abstract: In this paper, we make an attempt to describe the phenomenon of wave propagation when a disturbance is introduced in an electromechanical system. The focus is mainly on generator trips in a power system. Ordering of the generators is first done using a sensitivity matrix. Thereafter, orthogonal decomposition of the ordered generators is done to group them based on their participation in different modes. Finally, we find the velocity of propagation of the wave and the transport delay associated with it using the ESPRIT method. The analysis done on generators from the eastern and western regions of India.1

Transverse surface waves in magneto-elasticity

1966 ◽  
Vol 62 (3) ◽  
pp. 541-545 ◽  
Author(s):  
C. M. Purushothama
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Surface Waves ◽  
Elastic Medium ◽  
Uniform Magnetic Field ◽  
Shear Waves ◽  
Plane Shear ◽  
Electrically Conducting ◽  
Velocity Of Propagation

AbstractIt has been shown that uncoupled surface waves of SH type can be propagated without any dispersion in an electrically conducting semi-infinite elastic medium provided a uniform magnetic field acts non-aligned to the direction of wave propagation. In general, the velocity of propagation will be slightly greater than that of plane shear waves in the medium.

Characteristic Analysis on Suppressing VFTO in GIS by Ferrite

2013 ◽  
Vol 834-836 ◽  
pp. 385-389
Author(s):  
Xiang Gen Gan ◽  
Shui Ping Zhong ◽  
Sheng Wei ◽  
Dong Bao Yang
Keyword(s):  
Wave Propagation ◽  
Power Systems ◽  
Traveling Wave ◽  
Low Voltage ◽  
Characteristic Analysis ◽  
Fast Transient ◽  
Transient Overvoltage ◽  
Great Harm

When disconnecting switches were operated,Very Fast Transient Overvoltage (VFTO) did great harm to power systems and their equipments in Gas Insulated Substations (GIS). Although VFTO can be suppressed by a few of known methods, there were some problems. Low voltage simulation tests show that putting ferrite rings around a disconnecting generatrix can damp traveling wave propagation and suppress VFTO in GIS. This method is economic and practical. We had analyzed ferrite characteristics of suppressing VFTO and got hold of ways of calculating ferrite size in GIS. Investigation shows that ferrite characteristics and sizes have a great effect on suppressing VFTO.

A Systematic Comparison and Multi-Objective Optimization of Humid Power Cycles—Part I: Thermodynamics

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
R. M. Kavanagh ◽  
G. T. Parks
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Search Algorithm ◽  
Working Fluid ◽  
Specific Work ◽  
Humid Air ◽  
System Parameters ◽  
Multi Objective ◽  
Air Turbine ◽  
The Impact

The steam injected gas turbine (STIG), humid air turbine (HAT), and TOP Humid Air Turbine (TOPHAT) cycles lie at the center of the debate on which humid power cycle will deliver optimal performance when applied to an aeroderivative gas turbine and, indeed, when such cycles will be implemented. Of these humid cycles, it has been claimed that the TOPHAT cycle has the highest efficiency and specific work, followed closely by the HAT, and then the STIG cycle. In this study, the systems have been simulated using consistent thermodynamic and economic models for the components and working fluid properties, allowing a consistent and nonbiased appraisal of these systems. Part I of these two papers focuses purely on the thermodynamic performance and the impact of the system parameters on the performance; Part II will study the economic performance. The three humid power systems and up to ten system parameters are optimized using a multi-objective Tabu Search algorithm, developed in the Cambridge Engineering Design Centre.

Wave Motion of a Nonlinear Elastic Bar Subjected to Axial Excitation

2004 ◽  
Author(s):  
Liming Dai ◽  
Qiang Han
Keyword(s):  
Wave Propagation ◽  
Solitary Wave ◽  
Elastic Wave ◽  
Nonlinear Wave ◽  
Wave Motion ◽  
Initial Conditions ◽  
System Parameters ◽  
Elastic Bar ◽  
Nonlinear Elastic ◽  
Nonlinear Elastic Wave

This research intends to investigate the wave motion in a nonlinear elastic bar with large deflection subjected to an axial external exertion. A nonlinear elastic constitutive relation governs the material of the bar. General form of the nonlinear wave equations governing the wave motion in the bar is derived. With a modified complete approximate method, the asymptotic solution of solitary wave is developed for theoretical and numerical analyses of the wave motion. Various initial conditions and system parameters are considered for investigating the shape and propagation of the nonlinear elastic wave. With the governing equation of the wave motion of the bar and the solution developed, the characteristics of the nonlinear elastic wave of the bar are analyzed theoretically and numerically. Properties of the wave propagation and the effects of the system parameters of the bar and the influences of the initial conditions to the characteristics of the wave motion are investigated in details. Based on the theoretical analysis as well as the numerical simulations, it is found that the nonlinearity of the elastic bar may cause solitary wave in the bar. The velocity of the solitary wave propagating in the bar is related to the initial condition of the wave motion. This exhibits an obvious different characteristic between the nonlinear wave and that of the linear wave of an elastic bar. It is also found in the research that the solitary wave is a pulse wave with stable propagation. If the stability of the wave propagation is destroyed, the solitary wave will no longer exist. The results of the present research may provide guidelines for the wave motion analysis of nonlinear elastic solid elements.

scholarly journals Consistency of students’ conceptions of wave propagation: Findings from a conceptual survey in mechanical waves

2011 ◽  
Vol 7 (2) ◽  
Author(s):  
Apisit Tongchai ◽  
Manjula Devi Sharma ◽  
Ian D. Johnston ◽  
Kwan Arayathanitkul ◽  
Chernchok Soankwan
Keyword(s):  
Wave Propagation ◽  
Mechanical Waves

A Systematic Comparison and Multi-Objective Optimisation of Humid Power Cycles: Part II—Economics

2008 ◽  
Author(s):  
Ronan M. Kavanagh ◽  
Geoffrey T. Parks
Keyword(s):  
Power Systems ◽  
Gas Turbine ◽  
Search Algorithm ◽  
Working Fluid ◽  
Specific Work ◽  
Power Cycles ◽  
System Parameters ◽  
Multi Objective ◽  
Fluid Properties ◽  
The Impact

The STIG, HAT and TOPHAT cycles lie at the centre of the debate on which humid power cycle will deliver optimal performance when applied to an aero-derivative gas turbine and, indeed, when such cycles will be implemented. Of these humid cycles, it has been claimed that the TOPHAT cycle has the highest efficiency and specific work, followed closely by the HAT (Humid Air Turbine) and then the STIG (STeam Injected Gas turbine) cycle. In this study, the systems have been simulated using consistent thermodynamic and economic models for the components and working fluid properties, allowing a consistent and non-biased appraisal of these systems. Part 1 of these two papers focussed on the thermodynamic performance and the impact of the system parameters on the performance, part 2 studies the economic performance of these cycles. The three humid power systems and up to ten system parameters are optimised using a multi-objective Tabu Search algorithm, developed in the Cambridge Engineering Design Centre.

Position Control of Flexible Robot Arms Using Mechanical Waves

1998 ◽  
Vol 120 (3) ◽  
pp. 334-339 ◽  
Author(s):  
William O’Connor ◽  
Donogh Lang
Keyword(s):  
Position Control ◽  
Flexible Robot ◽  
Reflected Waves ◽  
Robot Arms ◽  
Lumped Parameter ◽  
Mechanical Waves ◽  
Time Optimal ◽  
Active Vibration Damping ◽  
Active Vibration ◽  
Spring System

A novel position control strategy for flexible robot arms based on wave propagation and absorption techniques is presented. The arm is modeled by a lumped-parameter mass-spring system with an actuator at one end and a load mass at the other. The actuator is required to position the remote load and, simultaneously, to provide active vibration damping. It does so by propagating mechanical waves through the system and absorbing reflected waves. Only the first two masses and springs need to be characterized and observed to determine the required actuator movement. The control algorithm is robust and compares very favorably with the time-optimal performance of bang-bang control. It is also inherently adaptive.

Chaotic dynamics for a class of single-machine-infinite bus power system

2016 ◽  
Vol 24 (3) ◽  
pp. 582-587 ◽  
Author(s):  
Liangqiang Zhou ◽  
Fangqi Chen
Keyword(s):  
Power Systems ◽  
Power System ◽  
Single Machine ◽  
Chaotic Dynamics ◽  
Numerical Results ◽  
Chaotic Motions ◽  
System Parameters ◽  
Critical Curves ◽  
Single Machine Infinite Bus

The chaotic motions are investigated both analytically and numerically for a class of single-machine-infinite bus power systems. The mechanism and parametric conditions for chaotic motions of this system are obtained rigorously. The critical curves separating the chaotic and non-chaotic regions are presented. The chaotic feature of the system parameters is discussed in detail. It is shown that there exist chaotic bands for this system, and the bands vary with the system parameters. Some new dynamical phenomena are presented. Numerical results are given, which verify the analytical ones.

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