Experimental and numerical vibration response comparison of mono and hybrid structural system for tall wind mill

Abstract

India is one of the leading countries in wind power generation and has produced 4 GW wind power with second largest wind power generation in Asia. The wind turbines are supported by mono type or lattice type structural system towers and subjected to heavy mass of blade and rotor at top. At given location more power can be extracted by increasing hub height of wind mill. But by increasing height of structure owing to very tall slender structure, tower may experience vibrations by operation of wind turbine, so detailed dynamic analysis considering excitation frequencies are required. To overcome slenderness effects of such long slender wind mill an alternative hybrid supporting system which is combination of mono and lattice structural system is proposed in present investigation. This paper summarizes results obtained from 1:40 scaled model of prototype structure developed in laboratory supported on two types of supporting systems such as monotype and hybrid type. Both systems are excited by operating frequencies of wind mill turbine and responses are quantified in terms of displacement in time domain. The obtained experimental results of both systems are authenticated using FE simulation. The dynamic response of both systems is compared in form of displacement, stresses and shear at base. From obtained experimental and its simulation results, it can be concluded that owing to more stiffness hybrid structural system proves less sensitive to dynamic forces and can be used for tall wind mill structure to yield more power for tall wind mill structures.