The generalized Hamiltonian model for the shafting transient analysis of the hydro turbine generating sets

Abstract

However, for systems such as hydro turbine generating sets (HTGS) where the control and regulation is frequently applied, the shafting safety and stabilization in transient state is then a key factor. The shafting transient state inevitably involves multi-parameter domain, multi-field coupling and coupling dynamics. In this paper, the relative value form of the Lagrange function and its equations have been established by defining the base value system of the shafting. Taking the rotation angle and the angular speed of the shafting as a link, the shafting lateral vibration and generator equations are integrated into the framework of the generalized Hamiltonian system. The generalized Hamiltonian control model is thus established. To make the model be more general, additional forces of the shafting are taken as the input excitation in proposed model. The control system of the HTGS can be easily connected with the shafting model to form the whole simulation system of the HTGS. It is expected that this study will build a foundation for the coupling dynamics theory using the generalized Hamiltonian theory to investigate coupling dynamic mechanism between the shafting vibration, transient of hydro turbine generating sets and additional forces of the shafting.

Analysis of Nonlinear Dynamic Characteristics of a Mechanical-Electromagnetic Vibration System with Rubbing

“…In Gustavsson et al [19]'s paper, the influence of nonlinear magnetic pull was studied for a generator where the generator spider hub does not coincide with the center of the generator rim; Perers et al [20] studied the mechanism of unbalanced magnetic pull generated by a synchronous generator with static eccentricity, and discussed the influence of iron saturation on the magnitude of magnetic pull. Lundström et al [21] analyzed the influence of the rotor and stator shape deviation on the dynamic characteristics of the generator, and proved the importance of the unbalanced magnetic pull nonlinear influence; Calleecharan et al [22] proposed a rotor model considering radial and tangential unbalanced magnetic pull forces; Xu et al [23] studied the effect of UMP on radial vibration of hydroelectric generators, and compared and analyzed the simulation results and the field experimental data; Zeng et al [24] established the hydro turbine generating sets dynamics model by using the unbalanced magnetic pull force acting on the generator and the unbalanced force acting on the rotor as the input excitation of the hydro turbine generating sets system; Xu et al [25] established a hydro-generator dynamics model considering the nonlinear unbalanced magnetic pull force and the linear water unbalance force; Xu et al [26] studied the response characteristics of unbalanced magnetic pull rotor system considering both static and dynamic eccentricity. Xiang et al [27] analyzed the influence of unbalanced magnetic pull on the nonlinear dynamic characteristics of permanent magnet synchronous motors rotor system; Li et al [28] established a two-dimensional hydroelectric generator electromagnetic model, using the finite element method to study the characteristics of the electromagnetic flux and electromagnetic force; Yan et al [29] analyzed the influence of excitation current on the nonlinear dynamic behaviors of the generator.…”

Stability of multi-hydro-turbine governing time-delay systems with sharing tailrace surge tank

“…Fortunately, there are some contributions about the stability and time-delay effect of the hydro-turbine governing system [15][16][17][18][19][20]. For example, Zeng [15] integrated the generator equations and shafting lateral vibration into the generalized Hamiltonian system. Then the generalized Hamiltonian control model is proposed for hydro-turbine generating sets in the shafting transient state.…”

A New Processing Method Combined with BP Neural Network for Francis Turbine Synthetic Characteristic Curve Research

“…Many hydropower plants have been built worldwide to harness the energy of falling or running water for electricity purpose [1,2]. A lot of fruitful and meaningful works of hydropower turbine in advanced control [3][4][5][6], parameter identification [7][8][9], dynamics analysis [10,11], and fault diagnosis [12] have been done. In addition, obtaining of flow and torque characteristics from synthetic characteristic curve of a specific Francis turbine is the key to high-precision nonlinear simulation and stability analysis [13], which could serve to maintain safe, stable, and economical operation of hydropower generating unit.…”

“…In addition, obtaining of flow and torque characteristics from synthetic characteristic curve of a specific Francis turbine is the key to high-precision nonlinear simulation and stability analysis [13], which could serve to maintain safe, stable, and economical operation of hydropower generating unit. Thus, it is extremely important for hydroturbine governing system nonlinear modeling and control [4,8,11,14] to process the synthetic characteristic curve in a reasonable way. However, synthetic characteristic curves that provided by manufacturers nowadays are only in the high efficiency and large guide vane opening area in China, which is far from meeting the research requirements of transition process, especially in large fluctuations.…”