The Experts below are selected from a list of 10017 Experts worldwide ranked by ideXlab platform
Diyi Chen - One of the best experts on this subject based on the ideXlab platform.
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Hamiltonian Modeling and Energy Analysis of a Hydro Electric Generating Set in the Sudden Load Decreasing Transient
Volume 2: Fluid Mechanics; Multiphase Flows, 2020Co-Authors: Pengfei Wang, Diyi ChenAbstract:Abstract Hydroelectric generation system is mainly composed of penstock, hydro-turbine, generator, servicing facility and power Load, its stability is directly related to the dynamic characteristics of each subsystem, but not completely dependent on the behavior of the subsystems. To better study the transient energy characteristics and stabilization mechanism of the hydroelectric generating set in the Sudden Load decreasing transient. And make full use of strengths of generalized Hamiltonian system in describing energy flow, the Hamiltonian model of a hydroelectric generating set including the turbine, water diversion system and generator is established by the method of orthogonal decomposition. Firstly, the energy flow of the hydroelectric generating set in the framework of generalized Hamiltonian theory is proved theoretically to be consistent with the real system, and the transient process of Sudden Load decreasing can be described effectively. Moreover, the variation laws of the flow, the rotating speed and the power angle of the set in the Sudden Load decreasing transient are studied respectively. The results indicate that the constructed Hamilton function can effectively describe the energy change of the system. It provides theoretical support for the stable operation of the hydroelectric generating set in the Sudden Load decreasing transient, and a new research idea for the stable operation of the set in other transient processes.
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Stability analysis of nonlinear hydroelectric power generating system in the transition of Sudden Load decrease
Journal of the Chinese Institute of Engineers, 2020Co-Authors: Sengkong Khov, Diyi Chen, Kimleng KheavAbstract:This article presents the modeling and the dynamical behavior of a nonlinear hydroelectric power generating system with surge tank effects and its stability in the case of Sudden Load decrease. A n...
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hamiltonian analysis of a hydro energy generation system in the transient of Sudden Load increasing
Applied Energy, 2017Co-Authors: Diyi Chen, Hao Zhang, Xiangyu WangAbstract:This paper addresses the Hamiltonian mathematical modeling and dynamic analysis of a hydro-energy generation system in the transient of Sudden Load increasing. First, six dynamic transfer coefficients of the hydro-turbine for the transient of Sudden Load increasing are innovatively introduced into the hydro-energy generation system. Considering the elastic water-hammer model of the penstock and third-order model of the generator, we established a dynamic mathematical model of the hydro-energy generation system in the transient of Sudden Load increasing. Moreover, from the point of view of the transmission and dissipation of energy of the system, we propose the hydro-energy generation system into the theory frame of the generalized Hamiltonian system. A novel Hamiltonian model of the hydro-energy generation system is established utilizing the method of orthogonal decomposition. Finally, based on the data of a real hydropower plant, numerical simulations and physical experiment are carried out, and the results indicates that the Hamiltonian system can reflect the essence of the nonlinearity of the hydro-energy generation system in the transient of Sudden Load increasing. More importantly, these methods and results will supply theoretical basis for designing and running a hydropower plant.
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nonlinear modeling and dynamic analysis of a hydro turbine governing system in the process of Sudden Load increase transient
Mechanical Systems and Signal Processing, 2016Co-Authors: Diyi Chen, Hao Zhang, Feifei WangAbstract:Abstract In order to study the nonlinear dynamic behaviors of a hydro-turbine governing system in the process of Sudden Load increase transient, we establish a novel nonlinear dynamic model of the hydro-turbine governing system which considers the elastic water-hammer model of the penstock and the second-order model of the generator. The six nonlinear dynamic transfer coefficients of the hydro-turbine are innovatively proposed by utilizing internal characteristics and analyzing the change laws of the characteristic parameters of the hydro-turbine governing system. Moreover, from the point of view of engineering, the nonlinear dynamic behaviors of the above system are exhaustively investigated based on bifurcation diagrams and time waveforms. More importantly, all of the above analyses supply theoretical basis for allowing a hydropower station to maintain a stable operation in the process of Sudden Load increase transient.
Puntani Pongsumpun - One of the best experts on this subject based on the ideXlab platform.
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simplified modeling approach to characterize Sudden Load disturbances in wirelesshart fopdt systems
International Conference on Control Automation Robotics and Vision, 2018Co-Authors: Napasool Wongvanich, Puntani PongsumpunAbstract:This paper presents the simplified modelling approach to characterize Sudden Load disturbance in WirelessHART™. Two approaches are presented. The model was firstly formulated through Laplace transformation, where the resulting integral equation renders non-linear optimization problems into simple linear optimizations. Experiments were conducted on a coupled tanks system connected through the WirelessHART™ protocol. Based on the initial fit to the experimental results, the second model then places two locally affine relationships, one for the Load flow disturbances, and the other for the level measurements to the responses. The extended locally affine model gave on average a 25% reduction in errors, compared to the Laplace-based method, while better captured the non-linear effects resulting from the WirelessHART™.
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ICARCV - Simplified Modeling Approach to Characterize Sudden Load Disturbances in WirelessHART FOPDT Systems
2018 15th International Conference on Control Automation Robotics and Vision (ICARCV), 2018Co-Authors: Napasool Wongvanich, Puntani PongsumpunAbstract:This paper presents the simplified modelling approach to characterize Sudden Load disturbance in WirelessHART™. Two approaches are presented. The model was firstly formulated through Laplace transformation, where the resulting integral equation renders non-linear optimization problems into simple linear optimizations. Experiments were conducted on a coupled tanks system connected through the WirelessHART™ protocol. Based on the initial fit to the experimental results, the second model then places two locally affine relationships, one for the Load flow disturbances, and the other for the level measurements to the responses. The extended locally affine model gave on average a 25% reduction in errors, compared to the Laplace-based method, while better captured the non-linear effects resulting from the WirelessHART™.
Napasool Wongvanich - One of the best experts on this subject based on the ideXlab platform.
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simplified modeling approach to characterize Sudden Load disturbances in wirelesshart fopdt systems
International Conference on Control Automation Robotics and Vision, 2018Co-Authors: Napasool Wongvanich, Puntani PongsumpunAbstract:This paper presents the simplified modelling approach to characterize Sudden Load disturbance in WirelessHART™. Two approaches are presented. The model was firstly formulated through Laplace transformation, where the resulting integral equation renders non-linear optimization problems into simple linear optimizations. Experiments were conducted on a coupled tanks system connected through the WirelessHART™ protocol. Based on the initial fit to the experimental results, the second model then places two locally affine relationships, one for the Load flow disturbances, and the other for the level measurements to the responses. The extended locally affine model gave on average a 25% reduction in errors, compared to the Laplace-based method, while better captured the non-linear effects resulting from the WirelessHART™.
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ICARCV - Simplified Modeling Approach to Characterize Sudden Load Disturbances in WirelessHART FOPDT Systems
2018 15th International Conference on Control Automation Robotics and Vision (ICARCV), 2018Co-Authors: Napasool Wongvanich, Puntani PongsumpunAbstract:This paper presents the simplified modelling approach to characterize Sudden Load disturbance in WirelessHART™. Two approaches are presented. The model was firstly formulated through Laplace transformation, where the resulting integral equation renders non-linear optimization problems into simple linear optimizations. Experiments were conducted on a coupled tanks system connected through the WirelessHART™ protocol. Based on the initial fit to the experimental results, the second model then places two locally affine relationships, one for the Load flow disturbances, and the other for the level measurements to the responses. The extended locally affine model gave on average a 25% reduction in errors, compared to the Laplace-based method, while better captured the non-linear effects resulting from the WirelessHART™.
Christian Larivière - One of the best experts on this subject based on the ideXlab platform.
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Trunk response to Sudden forward perturbations - effects of preLoad and Sudden Load magnitudes, posture and abdominal antagonistic activation.
Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology, 2014Co-Authors: Ali Shahvarpour, Aboulfazl Shirazi-adl, Hakim Mecheri, Christian LarivièreAbstract:Unexpected Loading of the spine is a risk factor for low back pain. The trunk neuromuscular and kinematics responses are likely influenced by the perturbation itself as well as initial trunk conditions. The effect of four parameters (preLoad, Sudden Load, initial trunk flexed posture, initial abdominal antagonistic activity) on trunk kinematics and back muscles reflex response were evaluated. Twelve asymptomatic subjects participated in Sudden forward perturbation tests under six distinct conditions. PreLoad did not change the reflexive response of back muscles and the trunk displacement; while peak trunk velocity and acceleration as well as the relative Load peak decreased. Sudden Load increased reflex response of muscles, trunk kinematics and Loading variables. When the trunk was initially flexed, back muscles latency was delayed, trunk velocity and acceleration increased; however, reflex amplitude and relative trunk displacement remained unchanged. Abdominal antagonistic preactivation increased reflexive response of muscles but kinematics variables were not affected. PreLoad, initial flexed posture and abdominal muscles preactivation increased back muscles preactivity. Both velocity and acceleration peaks of the trunk movement decreased with preLoad despite greater total Load. In contrast, they increased in the initial flexed posture and to some extent when abdominal muscles were preactivated demonstrating the distinct effects of pre-perturbation variables on trunk kinematics and risk of injury.
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trunk response analysis under Sudden forward perturbations using a kinematics driven model
Journal of Biomechanics, 2009Co-Authors: Babak Bazrgari, A Shiraziadl, Christian LarivièreAbstract:Abstract Accurate quantification of the trunk transient response to Sudden Loading is crucial in prevention, evaluation, rehabilitation and training programs. An iterative dynamic kinematics-driven approach was used to evaluate the temporal variation of trunk muscle forces, internal Loads and stability under Sudden application of an anterior horizontal Load. The input kinematics is hypothesized to embed basic dynamic characteristics of the system that can be decoded by our kinematics-driven approach. The model employs temporal variation of applied Load, trunk forward displacement and surface EMG of select muscles measured on two healthy and one chronic low-back pain subjects to a Sudden Load. A finite element model accounting for measured kinematics, nonlinear passive properties of spine, detailed trunk musculature with wrapping of global extensor muscles, gravity Load and trunk biodynamic characteristics is used to estimate the response under measured Sudden Load. Results demonstrate a delay of ∼200 ms in extensor muscle activation in response to Sudden Loading. Net moment and spinal Loads substantially increase as muscles are recruited to control the trunk under Sudden Load. As a result and due also to the trunk flexion, system stability significantly improves. The reliability of the kinematics-driven approach in estimating the trunk response while decoding measured kinematics is demonstrated. Estimated large spinal Loads highlight the risk of injury that likely further increases under larger perturbations, muscle fatigue and longer delays in activation.
Xiangyu Wang - One of the best experts on this subject based on the ideXlab platform.
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hamiltonian analysis of a hydro energy generation system in the transient of Sudden Load increasing
Applied Energy, 2017Co-Authors: Diyi Chen, Hao Zhang, Xiangyu WangAbstract:This paper addresses the Hamiltonian mathematical modeling and dynamic analysis of a hydro-energy generation system in the transient of Sudden Load increasing. First, six dynamic transfer coefficients of the hydro-turbine for the transient of Sudden Load increasing are innovatively introduced into the hydro-energy generation system. Considering the elastic water-hammer model of the penstock and third-order model of the generator, we established a dynamic mathematical model of the hydro-energy generation system in the transient of Sudden Load increasing. Moreover, from the point of view of the transmission and dissipation of energy of the system, we propose the hydro-energy generation system into the theory frame of the generalized Hamiltonian system. A novel Hamiltonian model of the hydro-energy generation system is established utilizing the method of orthogonal decomposition. Finally, based on the data of a real hydropower plant, numerical simulations and physical experiment are carried out, and the results indicates that the Hamiltonian system can reflect the essence of the nonlinearity of the hydro-energy generation system in the transient of Sudden Load increasing. More importantly, these methods and results will supply theoretical basis for designing and running a hydropower plant.
