Dynamic Model for Hydro-Turbine Generator Units Based on a Database Method for Guide Bearings

Abstract

A suitable dynamic model of rotor system is of great significance not only for supplying knowledge of the fault mechanism, but also for assisting in machine health monitoring research. Many techniques have been developed for properly modeling the radial vibration of large hydro-turbine generator units. However, an applicable dynamic model has not yet been reported in literature due to the complexity of the boundary conditions and exciting forces. In this paper, a finite element (FE) rotor dynamic model of radial vibration taking account of operating conditions is proposed. A brief and practical database method is employed to model the guide bearing. Taking advantage of the method, rotating speed and bearing clearance can be considered in the model. A novel algorithm, which can take account of both transient and steady-state analysis, is proposed to solve the model. Dynamic response for rotor model of 125 MW hydro-turbine generator units in Gezhouba Power Station is simulated. Field data from Optimal Maintenance Information System for Hydro power plants (HOMIS) are analyzed compared with the simulation. Results illustrate the application value of the model in providing knowledge of the fault mechanism and in failure diagnosis.

Using Simplified Models to Assist Fault Detection and Diagnosis in Large Hydrogenerators

“…The second way used a linear model, where the journal bearing dynamic coefficients were determined under the operating conditions that provide the highest coincidence between the characteristic frequencies of both linear and nonlinear models. Xu et al [19] also used a nonlinear model, reducing the processing time by means of a database containing the journal bearings forces calculated previously for the several possible operating conditions.…”

“…In most of the references, the journal bearing dynamic coefficients were obtained using Reynolds bearing model, solving Reynolds equation by the Finite Difference Method (FDM). Nevertheless, Xu et al [19] used the Bently-Muszynska bearing model [22] and Wang et al [23] solved Reynolds equation using an approximated analytical solution through the Variable Separation Method. LHG shafts are modeled using Bernoulli beam element [11] or Timoshenko beam element [19].…”

“…Nevertheless, Xu et al [19] used the Bently-Muszynska bearing model [22] and Wang et al [23] solved Reynolds equation using an approximated analytical solution through the Variable Separation Method. LHG shafts are modeled using Bernoulli beam element [11] or Timoshenko beam element [19]. The Finite Element Method (FEM) was used in many of the recent articles, while the Transfer Matrix Method (TMM) is encountered in some older references [14,24].…”

A Review on Data-driven Predictive Maintenance Approach for Hydro Turbines/Generators

“…The physical models are often used to analyze the phenomenon and the characteristics of the faults of the HTG to obtain the principles of the faults. [14] presented a dynamic model for radial vibration of hydro turbine generator units to assist the machine health monitoring. A finite element (FE) rotor dynamic model of radial vibration taking account of operating conditions is proposed to deal with the complex boundary conditions and exciting forces.…”

Robust Fuzzy Control for Fractional-Order Uncertain Hydroturbine Regulating System with Random Disturbances

“…However, as we all know, the hydroturbine regulating system is integration of hydraulic, mechanical, and electrical parts. This complex composition makes it a strong coupling, nonlinear, and nonminimum phase system [10][11][12]. So the integer-order model may not be suitable for perfectly describing the hydroturbine regulating system.…”