Abstract: An apparatus and a method for operating a wind turbine capable of preventing the occurrence of damage of the blades by evading excessive irregular loads from acting on the blades in the slanting direction in the event of power failure when strong wind blows, are provided.

Abstract: A wind turbine which varies an active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With the construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: A structure of an upwind type wind turbine and the operating method thereof capable of preventing the occurrence of damage of the blades by evading excessive irregular loads from acting on the blades in the slanting direction in the event of power failure when strong wind blows, are provided. In the upwind type wind turbine having a nacelle supported for rotation on a support, the nacelle is rotated to a downwind position by rotating it by 180° from a normal upwind position and kept in stand-by condition at a downwind position when detected wind speed is higher than the predetermined cutout wind speed, which is the reference wind speed for shifting to an idle operation state. When the detected wind speed is higher than the DWSS wind speed determined based on the maximum permissible instantaneous wind speed, the nacelle is rotated from an upwind position to a downwind position and the yaw brake is released.

Abstract: A wind turbine capable of varying active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With this construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: A wind turbine capable of varying active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With this construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: An apparatus and a method for operating a wind turbine capable of preventing the occurrence of damage of the blades by evading excessive irregular loads from acting on the blades in the slanting direction in the event of power failure when strong wind blows, are provided.

Abstract: A wind turbine which varies an active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With the construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: A wind turbine which varies an active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With the construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: A wind turbine which varies an active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With the construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: A wind turbine which varies an active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With the construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: A wind turbine which varies an active annular plane area by composing such that blades are attached to a cylindrical rotor movable in the radial direction of the rotor, the blades being reciprocated in the radial direction by means of a blade shifting mechanism connected to the root of each blade, or the blade itself is divided so that the outer one of the divided blade is movable in the radial direction. With the construction, the wind turbine can be operated with a maximum output within the range of evading fatigue failure of the blades and rotor by adjusting the active annular plane area in accordance with wind speed.

Abstract: A structure of an upwind type wind turbine and the operating method thereof capable of preventing the occurrence of damage of the blades by evading excessive irregular loads from acting on the blades in the slanting direction in the event of power failure when strong wind blows, are provided.

Abstract: The blade structure of a wind turbine which has enough strength for sporadic large load and increased durability. The blade can be formed into a thinner blade profile, with which blade performance is improved, increased efficiency of the wind turbine is attainable, and the noise induced by Karman vortex street is reduced. The blade is made of metal and formed into a one-piece blade or a split-type blade consisting of a main blade body made of metal and a rear end member made of metal other than that of the main blade body, the rear end member being fixed to the rear end of the main blade body, dentation being formed in the trailing edge part of the blade along the length thereof, the dentation being shaped in a serration of triangular teeth, of trapezoidal teeth, or of sawteeth, the ratio(h/&dgr;) of the tooth height h to the thickness &dgr; of the boundary layer developed on the surface of the blade is: h/&dgr;=1.0˜10.0, and the ratio (h/p) of the tooth height h to the pitch p is: h/p=0.

Abstract: The blade structure of a wind turbine is provided which has enough strength for sporadic large load and increased durability. The blade can be formed into a thinner blade profile, with which blade performance is improved, increased efficiency of the wind turbine is attainable, and the noise induced by Karman vortex street is reduced.

Abstract: An improved centrifugal fan in which a fan blade is supported by a main plate and a side plate and said main plate is connected to a rotation shaft, characterized in that between the rotation shaft and the main plate, there is interposed a doughnut-shaped connecting plate penetrated by the rotation shaft at the central part thereof, the connecting plate is fixed to the rotation shaft and to the main plate, at the inner and outer circumferential parts of the connecting plate, respectively, a plurality of through holes are provided in the inner and outer circumferential parts of the connecting plate in the circumferential directions, respectively, and slits are formed between each pair of two opposite through holes positioned obliquely with respect to the direction of radius of the connecting plate. Non-reversible displacement of the center of the fan blade is avoided which is a major factor in the vibration of the fan blade.