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COB63 CONSTRUÇÃO DE UM ROTOR EÓLICO COM TRÊS PÁS DE MADEIRA / CONSTRUCTION OF A WIND ROTOR WITH THREE WOODEN BLADES

Francisco José Simões & Jorge E.J. Serey Lopez

Núcleo de Energia (NERG), Centro de Ciências e Tecnologia - UFPB - Campina Grande

Av. Aprígio Veloso, s/n - CEP 58109-970 Campina Grande, PB, Brasil - E-mail: nerg@dee.ufpb.br

The construction of a 5 m diameter, three bladed horizontal axis wind rotor is presented. The blades are made of laminated wood and they have their pitches controlled by a synchronised centrifugal device. Simple solutions are employed to allow rotor fabrication in small workshops with common machines.

Keywords: Energia eólica, rotor eólico, métodos de fabricação / Wind energy, wind rotor, fabrication methods.

COB114 INFLUENCE OF STEADY VERTICAL WIND PROFILES ON WIND TURBINES CYCLIC LOADING AND STABILITY

Janardan Rohatgi, Issac Barbosa Viera Filho

Departamento de Engenharia Mecânica, Centro de Tecnolgia e Geociências, Universidade Federal de Pernambuco, CEP 50.741-000 Recife, Brasil - E-Mail: janardan@npd.ufpe.br

This paper analyses the influence of steady wind shear (vertical wind profile) on the wind turbines structural stability. The wind speed, in general, increases with altitude (up to about 500 to 1500 m) above the earth’s surface. However, for wind turbines, the altitude is limited to about 120 m at the most because beyond this level the cost of tower becomes prohibitive. It should be emphasized that we are talking about the wind turbine’s rotor diameter of the order of 15 m or more. Hence, the wind speed at the extreme points of the rotor disc, considering perpendicular to the upwind would certainly be different magnitude, results into wind shear. The latter would cause cyclic load 1/revolution. This paper describes very briefly the equations of blade motion that determine the dynamic stability. This equation then is used to estimate the load due to wind shear. We have assumed a linear shear profile. The effect of it is estimated to calculate the bending moments. A step by step procedure is shown so as to have a real feel of the complexity involved in it.

Keywords: Wind Energy, Wind Turbines, Dynamic Stability, Wind Shear, Cyclic loading.

COB1280 TURBINA EÓLICA OHM-30KW - CARACTERIZAÇÃO DA CURVA DE POTÊNCIA / WIND TURBINE OHM-30KW - POWER CURVE CHARACTERIZATION

Everaldo Feitosa, Alexandre Pereira, Maria Eliza Barros & Pedro Rosas

Grupo de Energia Eólica, Departamento de Engenharia Mecânica, Centro de Tecnologia e Geociências, Universidade Federal de Pernambuco, Cidade Universitária, 50.740-530, Recife, PE, Tel.: (081) 453-2975 Fax.: (081) 271-8232 E-mail: windcenter@npd.ufpe.br

An experimental 30 kW wind turbine OHM-30 has been installed in the Brazilian Wind Turbine Testing Center. The main aim of the project is development of special wind turbines for moderate wind. This paper presents the first part of the project involving the measurement of the power curve of the turbine OHM-30 according to I.E.A. (International Energy Agency). Several modifications in the turbine rotor and control strategies are emphasized.

Keywords: 1. turbina eólica / wind turbine 2. curva de potência / power curve

COB1145 MODELAGEM DE TURBINAS EÓLICAS CONTROLADAS PELO PASSO E POR "YAW" / WIND TURBINE PITCH AND YAW CONTROL MODELLING

Armando Medeiros

Grupo de Energia Eólica, UFPE/CTG/DEMEC - Av. Acad. Hélio Ramos, s.n. 50.740-530 Recife/PE, Brasil

Antônio M. N. Lima, Cursino B. Jacobina & F. J. Simões

UFPB/CCT/DEE - Av. Aprígio Velozo,882 -- 58.109-970 Campina Grande/PB, Brasil

This work presents the modelling of wind turbines operating above rated power. The new controller is designed to make the system operate close to the rated power by actuating on the blade pitch and on the yaw devices, simultaneously. Regarding the design of the controller, it is necessary to linearize the rotor torque function with respect to the rotor velocity, w, the pitch, q, and the yaw angle, d, around the steady state. The direction and velocity of the wind are considered random variables. Then, the closed loop representation of the wind turbine can be approximated, in the frequency domain, by a second order function. The optimal controller gain is also obtained by three different methods that lead to close results.

Keywords: Turbina eólica, Wind Turbine Pitch Control, Controle pelo passo da pá, Regulagem por "yaw", Yaw Power Control.