Analysis of Wind Turbine Vibration Characteristics during Startup and Shutdown Process
Abstract
Wind turbines vibrate under the excitation of environmental loads and rotor movement in normal operating conditions, and vibrations of the tower affect the service life of such system. In order to analyze the vibration and dynamic characteristics of the wind turbine during startup and shutdown process, vibration of a 1.5 MW turbine tower was monitored for a long term. First-order natural frequencies and damping ratios of the wind turbine were identified utilizing a data-driven stochastic subspace identification method. Monitoring data revealed that the wind turbine usually operated near the rotation speed of grid connection. In addition, obvious resonance at the turbine startup was noted as it surpassed the rotation speed of grid connection, but was not apparent at the turbine shutdown. Modal identification results revealed that the first-order natural frequencies varied slightly under different operating conditions, while the damping ratios were found to be smaller when the wind turbine started up, and its rotation speed surpassed that of grid connection, which were found to be greater at turbine shutdown. In addition, the characteristics of different vibration phenomena in the turbine during startup and shutdown processes were explained with the Sommerfeld effect. Our findings contribute to the field of vibration analysis and allow for more efficient optimization of dynamic parameters in wind turbines of similar design.
Keywords: wind turbine, startup and shutdown process, vibration monitoring, resonance, Sommerfeld effect
Full Text:
PDFReferences
KE S T, CAO J F, BANG L, et al. Time –domain analysis of the wind–induced responses of the coupled model of wind turbine tow– er–blade coupled system [J]. Journal of Hunan University(Natural Sciences), 2014, 41(4):87—93. ( In Chinese)
DNVGL–ST–0126 Support structures for wind turbines [S]. Nor– way:Det Norske Veritas, 2016 :35—36.
DEVRIENDT C, JORDAENS P J, SITTER G D, et al. Damping estimation of an offshore wind turbine on a monopile foundation[J]. Iet Renewable Power Generation, 2013, 7(4):401—412.
HU B H,SEBASTIAN T,ROLF G R,et al. Vibration–based struc– tural health monitoring of a wind turbine system. Part I:Resonance phenomenon[J]. Engineering Structures, 2015, 89:260—272.
SHIRZADEH R, DEVRIENDT C, BIDAKHVIDI M A, et al. Experimental and computational damping estimation of an offshore wind turbine on a monopile foundation[J]. Journal of Bind Engineering & Industrial Aerodynamics, 2013, 120:96—106.
TEMPEL J V D. Design of support structures for offshore wind turbines [D]. Holland:Offskore Engineering and Bind Energy Sections, Technische Universiteit Delft, 2006: 51—58.
DAMGAARD M,IBSEN L B, ANDERSEN L V,et al. Cross–wind modal properties of offshore wind turbines identified by full scale testing [J]. Journal of Bind Engineering and Industrial Aerodynamiss, 2013, 116(5):94—108.
VERSTEIJLEN B G, METRIDINE A, HOVING J S,et al. Estimation of the vibration decrement of an offshore wind turbine support structure caused by its interaction with soil [J]. Knowledge Technology & Polcy, 2011, 27(30):290—300.
HACDELL M B,ROLFES R. Monitoring a 5 MB offshore wind energy converter condition parameters and triangulation based ex– traction of modal parameters [J]. Mechanical Systems & Signal Processing, 2013, 40(1):322—343.
LIU P,LIAN P Y,ZHANG M Y,et al. Dynamic characteristics of a building with seismic joints based on ambient vibration[J]. Journal of Hunan University (Natural Sciences), 2017, 44(1):95—101. (In Chinese)
BROBNJOHN J M W, MAGALHAES F,CAETANO E,et al. Ambient vibration retesting and operational modal analysis of the Humber Bridge [J]. Engineering Structures, 2010, 32 (8):2003— 2018.
SHI W, SHAN J, LU X. Modal identification of Shanghai World Financial Center both from free and ambient vibration response[J]. Engineering Structures, 2012, 36(4):14—26.
Refbacks
- There are currently no refbacks.
