The rotordynamic analysis of the vibration considering the hydro-electric force supported by rolling elements in 500 kW Francis turbine

Kim, Jung-wan; Kwak, Wonil; Choe, Bokseong; Kim, Hyoung-Ho; Suh, Sang Hyun; Lee, Yong-Bok

doi:10.1007/s12206-017-1009-0

Cited by 10 publications

(3 citation statements)

References 9 publications

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“…Some of the effects are decreased natural frequencies due to dynamic eccentricity and the display of additional electromagnetic excitations. This was seen by Kim et al (2017) [10], where the first natural frequency of a Francis turbine unit decreased by 12% due to UMP.…”

Section: Introductionmentioning

confidence: 95%

Effect of unbalancing mass placement in hydropower generators with floating rotor rim

Rondon

Aidanpää

Gustavsson

2022

IOP Conf. Ser.: Earth Environ. Sci.

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Dynamic models for hydropower generators treat the rotor part as a rigid body; however, many studies have shown the opposite. The electromagnetic force distribution of deformed rotors is uneven, creating Unbalance Magnetic Pull, causing high forces on generator components leading to a risk of fatigue, therefore shortening the life of machines. Unbalancing masses can worsen the asymmetries of the rotor, which would further increase the effect of the electromagnetic interactions. This paper evaluates the rotor response using different unbalancing masses at the rotor and at the poles to quantify their impact in displacements and exciting frequencies. The model employed in this paper is based on the equation of motion derived using Lagrange equations in both co-rotating and stationary frames of reference, considering the effects of Centrifugal loads, Coriolis, and magnetization of poles. Different unbalancing mass placements affect different variables; extra weights in the poles contribute predominantly to the deformation of the rim, while the unbalance in the shaft affects the position of the shaft; a combination of placements was also studied. The simulations were performed and compared with and without radial electromagnetic forces, showing how the presence of magnetized poles further deforms the shapes of the rotor.

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Section: Introductionmentioning

confidence: 95%

Effect of unbalancing mass placement in hydropower generators with floating rotor rim

Rondon

Aidanpää

Gustavsson

2022

IOP Conf. Ser.: Earth Environ. Sci.

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“…When the hydro-turbine generator unit is in a stable operation with a small perturbation, and the unsteady boundary of the oil film is set to be a steady boundary, the oil film force [31] is adopted as…”

Section: Oil Film Force Modelmentioning

confidence: 99%

“…where F x0 and F y0 are oil film forces in the quiescent operation point; k xx , k xy , k yx , k yy , d xx , d xy , d yx and d yy are coefficients, which can be obtained from reference [31].…”

Section: Oil Film Force Modelmentioning

confidence: 99%

Dynamic Analyses of the Hydro-Turbine Generator Shafting System Considering the Hydraulic Instability

Zhuang

Gao

et al. 2018

Energies

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Hydraulic instability is a complex factor causing the vibration of hydro-turbine generator shafting system (HGSS), and the mechanism is the uneven distribution of flow along the circumference. The common reasons for this phenomenon include the inconsistency of the blade exit flow angle, the relay stroke and the guide vane opening. This paper mainly focuses on the research of the hydraulic instability caused by the inconsistency of the blade exit flow angle. Firstly, based on the Kutta-Joukowski theorem, the hydraulic unbalance force model is firstly presented. Then, considering the chain reaction among the hydraulic, mechanical and electrical instability, a combined nonlinear mathematical model of the HGSS is established. Finally, by using numerical simulation, the dynamic characteristics of the HGSS with the changing of the deviation of the blade exit flow angle, the blade exit diameter and the guide vane opening angle are analyzed. Moreover, it is found that the hydraulic instability determines the overall changing trend of the shafting dynamic behaviors. In addition, some stable ranges of the HGSS are distinguished. But above all, these results can efficiently provide a reference for the design and manufacture of hydro-turbine blades and the operation of hydropower stations.

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Dynamic evolution of a bulb hydroelectric generating unit considering effects of the blades

Yan

Chen

Wang

et al. 2019

Energy Conversion and Management

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The rotordynamic analysis of the vibration considering the hydro-electric force supported by rolling elements in 500 kW Francis turbine

Cited by 10 publications

References 9 publications

Effect of unbalancing mass placement in hydropower generators with floating rotor rim

Effect of unbalancing mass placement in hydropower generators with floating rotor rim

Dynamic Analyses of the Hydro-Turbine Generator Shafting System Considering the Hydraulic Instability

Dynamic evolution of a bulb hydroelectric generating unit considering effects of the blades

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