Switched Model and Dynamic Analysis of a Hydroturbine Governing System in the Process of Load Rejection Transient

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Huanhuan Li ◽  
Diyi Chen ◽  
Feifei Wang ◽  
Hao Zhang
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Numerical Simulations ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Hydropower Station ◽  
Transfer Coefficients ◽  
Operational Conditions ◽  
Governing System ◽  
Hammer Impact

In this paper, we pay attention to studying the switched model of the hydroturbine governing system (HTGS) by introducing the concept of the switching of operational conditions. More specifically, utilizing the data of an existent hydropower station in China, we propose six nonlinear dynamic transfer coefficients of the hydroturbine, which can better describe the dynamic characteristics of the HTGS in the process of load rejection transient. Moreover, the elastic water hammer-impact of the penstock system and the nonlinearity of the generator for the process of load rejection transient are considered. Based on the combination of the different regulation modes of the governor and the corresponding running conditions of the hydroelectric generating unit, a novel nonlinear dynamic switched mathematical model of the HTGS is finally established. Meanwhile, the nonlinear dynamic behaviors of the governing system are exhaustively investigated using numerical simulations. These methods and analytical results will provide some theory bases for running a hydropower station.

Research of Simulation Model for Non-Linear Turbine Regulating System

2011 ◽  
Vol 354-355 ◽  
pp. 569-574 ◽  
Author(s):  
Mei Feng Sun ◽  
Rui Lian Wang ◽  
Jia Wang ◽  
Jing Bin Lu
Keyword(s):  
Mathematical Model ◽  
Simulation Model ◽  
Transition Process ◽  
Hydraulic Turbine ◽  
Large Fluctuation ◽  
Transfer Coefficients ◽  
Operating Condition ◽  
Hydro Turbine ◽  
Governing System ◽  
The Mathematical Model

In the large fluctuation transition process of hydropower unit, hydraulic turbine operating condition changes drastically, following the change, hydraulic-turbine transfer coefficients also change drastically, thus the mathematical model of hydro-turbine governing system is nonlinear. This paper establishes simulation model of large fluctuation transition process in SIMULINK software, puts forward a method of establishing simulation model of nonlinear hydro-turbine governing system.

Simulation and Test for Nonlinear Dynamic Specialty of Rubber Mounting

2013 ◽  
Vol 774-776 ◽  
pp. 30-34
Author(s):  
Pei Cheng Shi ◽  
Yang Min Sun
Keyword(s):  
Mathematical Model ◽  
Simulation Model ◽  
Frequency Domain ◽  
Dynamic Characteristics ◽  
High Frequency ◽  
Nonlinear Dynamic ◽  
Mechanical Model ◽  
Engineering Application ◽  
Nonlinear Mathematical Model ◽  
Nonlinear Simulation

On the basis of a newly-built mechanical model of rubber mounting and nonlinear mathematical model, the dynamic characteristics of rubber mounts were simulated and contrastively tested in frequency domain by using simulation software.Results indicate that the nonlinear simulation model of rubber mounts built in this paper can apply to the research of the low and high frequency vibration of rubber mounts.This model can also be applied to the design of rubber mounting products, which has certain engineering application value.

Comportement dynamique des lignes aériennes de transport d'électricité dû aux bris de câbles. I. Modélisation mathématique

1989 ◽  
Vol 16 (3) ◽  
pp. 335-353 ◽  
Author(s):  
Ghyslaine McClure ◽  
René Tinawi
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Transmission Lines ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Physical Models ◽  
Element Analysis ◽  
Electric Transmission ◽  
Electric Transmission Lines ◽  
Supporting Structures

This paper presents a mathematical model for the nonlinear dynamic analysis of aerial electric transmission lines subjected to conductor breakage. The model uses existing finite elements and validated numerical techniques available in most commercial programs capable of handling nonlinear dynamic analysis. ADINA is used in this study. In comparison with other models, the novel approach presented here focusses on the discretization of the conductors as well as the supporting structures, specially near the breakage point. Dynamic interactions between all the structural components are therefore considered and comparisons with simpler models emphasize the importance of these interactions, the effects of geometric nonlinearities present in the conductors and in the supporting structures, and the contribution of higher modes.The mathematical model is validated with 7 of 56 tests conducted on reduced-scale physical models, reported in work done for the American Electric Power Research Institute.The results of the present study are very encouraging for designers interested in validating their design criteria for longitudinal dynamic loads by use of existing nonlinear dynamic finite element analysis packages. Key words: Nonlinear dynamic analysis, electric transmission lines, conductor breakage simulation.

ON A NONIDEAL (MRD) DAMPER-ELECTRO-MECHANICAL ABSORBER DYNAMICS

2011 ◽  
Vol 21 (10) ◽  
pp. 2871-2882 ◽  
Author(s):  
JORGE L. P. FELIX ◽  
JOSÉ M. BALTHAZAR ◽  
MARCIO J. H. DANTAS
Keyword(s):  
Mathematical Model ◽  
Numerical Simulations ◽  
Dynamic Behavior ◽  
Perturbation Analysis ◽  
Nonlinear Dynamic ◽  
Mechanical Vibration ◽  
Mr Damper ◽  
Vibration Absorber ◽  
Nonlinear Dynamic Behavior

In this paper, we have investigated the nonlinear dynamic behavior of an electro-mechanical vibration absorber (NEVA), taking into account a modified (MR) Damper (MRD), in its mathematical model, which was excited by a nonideal motor (NIS), by using perturbation analysis and numerical simulations.

Nonlinear dynamic analysis for a Francis hydro-turbine governing system and its control

2014 ◽  
Vol 351 (9) ◽  
pp. 4596-4618 ◽  
Author(s):  
Diyi Chen ◽  
Cong Ding ◽  
Younghae Do ◽  
Xiaoyi Ma ◽  
Hua Zhao ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Hydro Turbine ◽  
Governing System

Piecewise modeling and dynamic analysis of hydro-turbine governing system in the process of shutdown transient

2021 ◽  
pp. 2150129
Author(s):  
Yuansheng Chen ◽  
Fei Tong
Keyword(s):  
Transient Process ◽  
Continuous Time ◽  
Nonlinear Dynamic ◽  
Stable Operation ◽  
Transfer Coefficients ◽  
Hydro Turbine ◽  
Time Modeling ◽  
Governing System ◽  
Piecewise Continuous

This paper pays attention to the piecewise continuous time modeling of a hydro-turbine governing system in the process of shutdown transient. As a pioneering work, the piecewise nonlinear dynamic transfer coefficients are introduced into the system. Moreover, for different hydrographs of shutdown transient process, the effect of different shutdown laws on the quality of shutdown transient process has been analyzed by numerical simulations. The nonlinear dynamic behaviors of the hydro-turbine governing system are illustrated by bifurcation diagrams, Poincaré maps, time waveforms and phase orbits. More importantly, these methods and analytic results are useful for the safe and stable operation of a hydropower station in the process of shutdown transient.

scholarly journals Volterra–Lyapunov Stability Analysis of the Solutions of Babesiosis Disease Model

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1272
Author(s):  
Fengsheng Chien ◽  
Stanford Shateyi
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Global Stability ◽  
Numerical Simulations ◽  
Lyapunov Stability ◽  
Disease Model ◽  
Transmission Dynamics ◽  
Global Stability Analysis ◽  
Lyapunov Stability Analysis ◽  
Disease Free

This paper studies the global stability analysis of a mathematical model on Babesiosis transmission dynamics on bovines and ticks populations as proposed by Dang et al. First, the global stability analysis of disease-free equilibrium (DFE) is presented. Furthermore, using the properties of Volterra–Lyapunov matrices, we show that it is possible to prove the global stability of the endemic equilibrium. The property of symmetry in the structure of Volterra–Lyapunov matrices plays an important role in achieving this goal. Furthermore, numerical simulations are used to verify the result presented.

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