Abstract: A wind turbine blade includes a blade main body and a leading edge protector. The leading edge protector includes a conductive material and covers a leading edge of the blade main body. The leading edge protector is also electrically connected to a down conductor disposed in a hollow space enclosed by a skin in the blade main body or a conductive mesh member provided along an outer surface of the skin.

Abstract: A wind turbine blade includes a blade main body and a leading edge protector. The leading edge protector includes a conductive material and covers a leading edge of the blade main body. The leading edge protector is also electrically connected to at least one of a down conductor disposed in a hollow space enclosed by a skin in the blade main body and a conductive mesh member provided along an outer surface of the skin.

Abstract: A wind-turbine control device controls a wind turbine generator in which a rotor having a plurality of blades receives wind and rotates. The generator generates electrical power through the rotation of the rotor. The electrical power is supplied to a utility grid, and electric energy to be supplied to the utility grid can be changed according to a change in the frequency of the utility grid. The wind-turbine control device includes a subtracter to calculate a frequency change, which is the difference between a measurement value of the frequency of generated output power of the wind turbine generator and a set value of the frequency of the generated output power of the wind turbine generator. The wind-turbine control device further includes a limiter to limit a change in the electrical power corresponding to the frequency change calculated by the subtracter, based on the rotational speed of the generator.

Abstract: By means of a simple structure, lightning resistance is improved without increasing the level of fluid noise due to a lightning discharge member provided on a surface of a wind turbine blade. A wind turbine rotor blade lightning discharger, in which a diverter strip serving as a lightning discharge member protrudes from a surface of a wind turbine blade that extends in a radial direction from a rotor head supported in a freely rotatable manner, includes a noise suppressing structure that suppresses the generation of a Karman vortex, which causes noise, on the downstream side of the diverter strip with respect to an airflow that flows at the surface of the wind turbine blade during rotation of the wind turbine rotor blade.

Abstract: A turbine controller of a wind turbine generator includes a generated-output-power command value creating section that creates a generated-output-power command value and an optimum-upper-and-lower-limit limiting section that limits the generated-output-power command value by means of an upper limit value and a lower limit value of the generated output power that are determined based on a power curve indicating the relationship between the generated output power and the rotational speed of the generator.

Abstract: In lightning protection equipment of a wind turbine, it is required to ease the maintenance with maintaining high safety. The lightning current received by a receptor of a blade is conducted to an earth line in the blade. The earth line is conducted to the internal space of the rotor head via the internal side space of the bearing for changing the pitch angle of the blade. It is possible to conduct the lightning current to the rotor head side without using the bearing as the current route and without using a sliding or wearing member such as a brash or the like.

Abstract: A wind turbine blade has a blade body 11, a plurality of receptors 12, 13 embedded in and exposed to the surface of the blade body 11, a conductor layer 14 provided on the surface of the blade body 11 and connecting the receptors 12, 13 with one another and a downconductor 21 connected to the receptors 12, 13 and provided in the blade body 11. The downconductor 21 may be embedded in an insulator.

Abstract: A variable-speed power generator includes a prime mover that generates motive power by using natural energy; a wound-rotor induction generator that includes a stator having a primary winding and a rotor having a secondary winding, which are connected to a power grid, the generator generating electric power based on the motive power generated by the prime mover; a power converter connected to the stator and the rotor; and a controller controlling wound-rotor induction generator. The controller responds to instructions, sent by the power grid, for supplying reactive power to the power grid. The response of the controller to an instruction for supplying reactive power to the power grid may include imposing limitations on the reactive power supplied by the power converter to the power grid and causing the wound-rotor induction generator to operate at a rotation speed set higher than or equal to a synchronous speed.

Abstract: By means of a simple structure, lightning resistance is improved without increasing the level of fluid noise due to a lightning discharge member provided on a surface of a wind turbine blade. A wind turbine rotor blade lightning discharger, in which a diverter strip serving as a lightning discharge member protrudes from a surface of a wind turbine blade that extends in a radial direction from a rotor head supported in a freely rotatable manner, includes a noise suppressing structure that suppresses the generation of a Karman vortex, which causes noise, on the downstream side of the diverter strip with respect to an airflow that flows at the surface of the wind turbine blade during rotation of the wind turbine rotor blade.

Abstract: A lightning strike simulation apparatus includes a storage device for storing lightning strike data, a setting unit for setting a simulation target in a simulation space, a downward leader advancing unit for advancing a downward leader from a lightning strike start position set by the setting unit, an upward leader advancing unit for advancing upward leaders from lightning strike-receiving candidate points set in the simulation space when a distance between a leading edge of the downward leader and a reference point is within a first threshold value, and a lightning strike point determination unit for, when a distance between a leading edge of the downward leader and a leading edge of any one of the upward leaders is within a second threshold value, determining that the lightning strike-receiving candidate point corresponding to the any one of the upward leaders is a lightning strike point.

Abstract: A variable-speed power generator includes a prime mover that generates motive power by using natural energy; a wound-rotor induction generator that includes a stator having a primary winding and a rotor having a secondary winding, which are connected to a power grid, the generator generating electric power based on the motive power generated by the prime mover; a power converter connected to the stator and the rotor; and a controller controlling wound-rotor induction generator. The controller responds to instructions, sent by the power grid, for supplying reactive power to the power grid. The response of the controller to an instruction for supplying reactive power to the power grid may include imposing limitations on the reactive power supplied by the power converter to the power grid and causing the wound-rotor induction generator to operate at a rotation speed set higher than or equal to a synchronous speed.

Abstract: A wind-turbine control device controls a wind turbine generator in which a rotor having a plurality of blades receives wind and rotates. The generator generates electrical power through the rotation of the rotor. The electrical power is supplied to a utility grid, and electric energy to be supplied to the utility grid can be changed according to a change in the frequency of the utility grid. The wind-turbine control device includes a subtracter to calculate a frequency change, which is the difference between a measurement value of the frequency of generated output power of the wind turbine generator and a set value of the frequency of the generated output power of the wind turbine generator. The wind-turbine control device further includes a limiter to limit a change in the electrical power corresponding to the frequency change calculated by the subtracter, based on the rotational speed of the generator.

Abstract: A lightning-strike detecting apparatus comprises: receptors (lightning members) that are provided at a plurality of locations on a wind turbine blade; lightning conductors that extend from these receptors to guide lightning-strike current to ground; a plurality of optical-fiber current sensors that are provided on the respective lightning conductors, detect lightning-strike current flowing in the lightning conductors, and output an optical signal; an optical signal converter that receives the individual optical signal output from these optical-fiber current sensors, converts the optical signals to the respective characteristic electrical signals, and outputs the electrical signals; and a controller that identifies the type of the electrical signal input from the optical signal converter, determines a lightning-strike spot on the basis of the type, and reports the lightning-strike spots.

Abstract: A lightning strike detector that can promptly detect a lightning strike to ensure safety and can accurately determine the position struck by the lightning with a simple, inexpensive, and highly reliable structure, is provided. The lightning strike detector includes an environment-detecting sensor member that detects a change in the environment of the internal space of a wind turbine blade, serving as a hollow structure, when the wind turbine blade is struck by lightning and is damaged, converts the environmental change into an electrical signal, and outputs the electrical signal; and a control unit (nacelle-side control system and ground-side control system) that receives the electrical signal, judges whether a lightning strike has occurred, and takes countermeasures against the lightning strike.

Abstract: Reactive power is supplied in accordance with a reactive-power supply instruction from a power grid while ensuring a variable-speed range of a wound-rotor induction generator.

Abstract: This invention improves accuracy of lightning strike simulation. There is provided a lightning strike simulation apparatus including a storage device for storing lightning strike data, a setting unit for setting a simulation target and the like in a simulation space, a downward leader advancing unit for advancing a downward leader from a lightning strike start position set by the setting unit, an upward leader advancing unit for advancing upward leaders from lightning strike-receiving candidate points set in the simulation space when a distance between a leading edge of the downward leader and a reference point is within a first threshold value, and a lightning strike point determination unit for, when a distance between a leading edge of the downward leader and a leading edge of any one of the upward leaders is within a second threshold value, determining that the lightning strike-receiving candidate point corresponding to the any one of the upward leaders is a lightning strike point.

Abstract: Reactive power is supplied in accordance with a reactive-power supply instruction from a power grid while ensuring a variable-speed range of a wound-rotor induction generator.

Abstract: A wind turbine blade has a blade body 11, a plurality of receptors 12, 13 embedded in and exposed to the surface of the blade body 11, a conductor layer 14 provided on the surface of the blade body 11 and connecting the receptors 12, 13 with one another and a downconductor 21 connected to the receptors 12, 13 and provided in the blade body 11. The downconductor 21 may be embedded in an insulator.