scholarly journals Modelling and Simulation of Tramway Transportation Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
A. Capasso ◽  
M. Ceraolo ◽  
R. Lamedica ◽  
G. Lutzemberger ◽  
A. Ruvio
Keyword(s):  
Time Domain ◽  
Energy Recovery ◽  
Simulation Models ◽  
Transportation Systems ◽  
General Purpose ◽  
Storage Device ◽  
Time Domain Simulation ◽  
Real Cost ◽  
Braking Energy Recovery ◽  
Track Analysis

Electrified guided vehicles typically face routes having a large number of acceleration and braking phases. The braking energy, since the feeding line presents nonreversible electrical feeding substations, can be recovered in the presence of other nearby vehicles. To improve braking energy recovery, one or more storage systems can be positioned along the track. Analysis of effectiveness for the considered solution requires time-domain simulation models, to be created through suitable simulation general-purpose languages or specialised languages/software. In this paper, three different tools for the considered existing tramway were developed, and the main examined characteristics have been compared to each other. Then, analysis of output results was also performed, demonstrating the real cost-effectiveness of introducing one storage device on the considered tramline in operation.

Modeling and Simulation for Super Capacitor Braking Energy Recovery Process of Micro EV

2011 ◽  
Vol 383-390 ◽  
pp. 7390-7395
Author(s):  
Jin Yu Qu ◽  
Li Yan Liang
Keyword(s):  
Energy Storage ◽  
Electric Vehicle ◽  
Energy Recovery ◽  
Discharge Rate ◽  
Recovery Process ◽  
Storage Device ◽  
Energy Storage Device ◽  
Super Capacitor ◽  
The Impact ◽  
Braking Energy Recovery

Super-capacitor is suitable as braking energy storage device for electric vehicle because of its high charge and discharge rate, long life, simple structure and reliable performance advantages. When driving motor of the electric vehicles runs on regenerative electric power state, it can not only provide braking force, but also charge to the energy storage device to recover the kinetic energy, thus endurance mileage of electric vehicle can be extended considerably. In this paper, braking energy recovery model was built by using the Matlab/Simulink software, and whole vehicle model based on automobile theory, the motor efficiency model and super-capacitor model were mainly included. Meanwhile some researches were made on the simulation, and the impact of the super-capacitor on the braking energy recovery was analyzed.

Transient Stability Analysis of Power System Based on Time Domain Simulation

2012 ◽  
Vol 263-266 ◽  
pp. 781-785 ◽  
Author(s):  
Liang Pi ◽  
Chen Wang ◽  
Wei Zheng
Keyword(s):  
Power System ◽  
Single Machine ◽  
Time Domain ◽  
Transient Stability ◽  
Simulation Models ◽  
Time Domain Simulation ◽  
Power System Stabilizers ◽  
Machine System ◽  
Single Machine Infinite Bus ◽  
Bus System

Single-machine infinite-bus system and two-machine system simulation models were built to study the power system transient stability. Based on time domain simulation, the effect of generator inertia time constant (τg), and excitation system ceiling voltage (Ke) on transient stability were analyzed by single-machine infinite-bus system. The changes of transient stability of two-machine system were also compared by means of power system stabilizers (PSS) and static VAR compensator (SVC). In particular, the system transient stability varied greatly in different locations of SVC. Finally, some suggestions concerning the improvement of power system transient stability were put forward.

scholarly journals Convolution-based time-domain simulation for fluidelastic instability in tube arrays

2021 ◽  
Author(s):  
Mingjie Zhang ◽  
Ole Øiseth
Keyword(s):  
Impulse Response ◽  
Response Function ◽  
Time Domain ◽  
Impulse Response Function ◽  
Time Domain Simulation ◽  
Unit Step ◽  
Tube Arrays ◽  
Unit Impulse ◽  
The Time Domain ◽  
Unit Impulse Response

AbstractA convolution-based numerical algorithm is presented for the time-domain analysis of fluidelastic instability in tube arrays, emphasizing in detail some key numerical issues involved in the time-domain simulation. The unit-step and unit-impulse response functions, as two elementary building blocks for the time-domain analysis, are interpreted systematically. An amplitude-dependent unit-step or unit-impulse response function is introduced to capture the main features of the nonlinear fluidelastic (FE) forces. Connections of these elementary functions with conventional frequency-domain unsteady FE force coefficients are discussed to facilitate the identification of model parameters. Due to the lack of a reliable method to directly identify the unit-step or unit-impulse response function, the response function is indirectly identified based on the unsteady FE force coefficients. However, the transient feature captured by the indirectly identified response function may not be consistent with the physical fluid-memory effects. A recursive function is derived for FE force simulation to reduce the computational cost of the convolution operation. Numerical examples of two tube arrays, containing both a single flexible tube and multiple flexible tubes, are provided to validate the fidelity of the time-domain simulation. It is proven that the present time-domain simulation can achieve the same level of accuracy as the frequency-domain simulation based on the unsteady FE force coefficients. The convolution-based time-domain simulation can be used to more accurately evaluate the integrity of tube arrays by considering various nonlinear effects and non-uniform flow conditions. However, the indirectly identified unit-step or unit-impulse response function may fail to capture the underlying discontinuity in the stability curve due to the prespecified expression for fluid-memory effects.

Study of HVDC System and Subsynchronous Oscillation

2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu
Keyword(s):  
Power Plant ◽  
Time Domain ◽  
Simulation Method ◽  
Time Domain Simulation ◽  
Stable Convergence ◽  
Turbine Generator ◽  
Plant Model ◽  
Subsynchronous Oscillation ◽  
Hvdc System ◽  
Simulation Results

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably

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