Abstract: Provided is a wind power generation apparatus to which general purpose inverters are applicable. An inverter in a constant-voltage mode is used. While a wind power generator is generating electricity, switching circuits are turned on and off at a controlled duty cycles to intermittently short-circuit an armature winding, boosting the voltage and controlling the rotational speed of a windmill rotating blade, with the result that the voltage applied to the inverter is made constant. At the activation, in order to prevent an excessive voltage from being generated while an inverter is changing from the stand-by state to the activated state, ON/OFF control of a switching circuit is performed to switch between the output voltage of a rectifier and the voltage generated at a resistor, with the result that the voltage is controlled and maintained at an appropriate value.

Abstract: A wind power generation control device which controls a wind power generator using a wind turbine blade having a fixed pitch angle is provided.

Abstract: When a wind velocity sensor detects a wind velocity higher than a predetermined level, a timer device starts a waiting timer function during an operation timer period shorter than the waiting timer period. After the waiting timer period is over, the waiting timer function is switched to an operation timer function, and a switching relay switches a generator to a motor only during an operation timer period. Then, a driving circuit performs a start assisting rotation. After the operation timer period is over, the waiting timer period re-starts. This process is repeated. When during this period, the number of rotations of a rotor monitored by a rotation number measuring device, based on the output voltage Vm of a three-phase conduction coil exceeds a predetermined number of rotations, the charging of a battery by a three-phase generator is started.

Abstract: When a wind velocity sensor detects a wind velocity higher than a predetermined level, a timer device starts a waiting timer function during an operation timer period shorter than the waiting timer period. After the waiting timer period is over, the waiting timer function is switched to an operation timer function, and a switching relay switches a generator to a motor only during an operation timer period. Then, a driving circuit performs a start assisting rotation. After the operation timer period is over, the waiting timer period re-starts. This process is repeated. When during this period, the number of rotations of a rotor monitored by a rotation number measuring device, based on the output voltage Vm of a three-phase conduction coil exceeds a predetermined number of rotations, the charging of a battery by a three-phase generator is started.

Abstract: When a wind velocity sensor detects a wind velocity higher than a predetermined level, a timer device starts a waiting timer function during an operation timer period shorter than the waiting timer period. After the waiting timer period is over, the waiting timer function is switched to an operation timer function, and a switching relay switches a generator to a motor only during an operation timer period. Then, a driving circuit performs a start assisting rotation. After the operation timer period is over, the waiting timer period re-starts. This process is repeated. When during this period, the number of rotations of a rotor monitored by a rotation number measuring device, based on the output voltage Vm of a three-phase conduction coil exceeds a predetermined number of rotations, the charging of a battery by a three-phase generator is started.

Abstract: A windmill, characterized by connecting blade root parts to a hub in the radial direction of a windmill shaft by an undercut, fitting structure which is suitable particularly for a small-sized windmill having FRP blades. By this structure, the blades can be connected to the hub at the blade root parts without basically requiring a bolt fastening structure, a reduction in the weight of the blades can be achieved, and the strength, rigidity and installation accuracy of connection parts between the blades and the hub can be satisfactorily maintained.

Abstract: A slide and sled combination designed for use on the side of a mountain in conjunction with the operation of ski lift, consists of a monorail extending the length of a mountain from the upper end near the top of a ski lift along a path containing curves, banked curves, and straight segments to the bottom of the mountain near the base of the ski lift. The monorail consists of, in cross-section, a tubular segment supported on a web. Sleds comprising shells are supported on and secured to the monorail by two sets of four wheels which engage the tubular segment. Each set of wheels are supported on bulkheads connected to the shell. A braking system controllable by an operator sitting in the shell includes brakes actuated by a lever that are adapted to engage the tubular segment at diametrically opposite points. Stabilizing wheels are provided on at least one of the bulkheads and are adapted to engage the web.