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: Provided is a wind power generation system intending to suppress an increase of torque when a voltage in a utility grid is restored, and to reduce a load to devices due to the torque. The blade control unit controls the pitch angle of the wind turbine blades such that a rotation speed of the power generator becomes equal to or greater than a synchronous rotation speed when the power control unit de-actuates the operations of the converter and the inverter, and controls the pitch angle of the wind turbine blades such that the pitch angle matches a target pitch angle that is determined based on one of a wind speed, a rotation speed of the power generator, and a requested output power when the power control unit re-actuates the operations of the converter and the inverter.

Abstract: An object is to improve the operating rate. A first switch is provided in a power line connecting a power generator to a power system, and a second switch that can be opened and closed by remote control is provided in the power line between the power generator and the first switch. In the second switch, a withstand current capability is set that allows current flowing in a low-voltage event and that withstands current having a value equal to or less than a current value specified by the thermal setting of the power generator. In the first switch, a withstand current capability is set that is superior to the withstand current capability of the second switch and that withstands current having a value equal to or less than the current value specified by the thermal setting of the power generator.

Abstract: A wind power generator generates power through a rotation of a rotor and is interconnected, and operated with its power generation output previously limited in order to be able to further supply the power to a power system in response to a decrease in system frequency. Thus, a concentrated control system derives a required restricted amount corresponding to a power generation output required to respond to the decrease in system frequency, derives a value by subtracting an amount corresponding to a latent power generation output with which the power generation output can be increased, from the required restricted amount, and sets a restricted amount of the power generation output in each wind power generator to perform the operation with the power generation output previously limited to respond to the decrease in system frequency, based on the above value.

Abstract: To prevent disconnection of wind turbine generators due to changes in wind conditions even if the wind turbine generators is operated to limit the power output. A plurality of wind turbine generators that generate electric power by the rotation of rotors are provided in a wind farm are interconnected and are operated while the power outputs are limited in advance so as to be able to further supply electric power to a utility grid in response to a decrease in the frequency or voltage of the utility grid. The rotational speed of the rotor, which is a physical quantity related to increase and decrease in the power output of the wind turbine generator, is measured for each of the wind turbine generators by a wind-turbine control system, and the limitation amount of the power output of the wind turbine generator is set for each of the wind turbine generators by a central control system on the basis of the rotational speed of the rotor measured.

Abstract: An object of the present invention is to, if a frequency decrease has occurred in a power system, avoid a trip in a wind turbine generator and reliably contribute to recovery of the frequency of the power system. The present invention provides a wind turbine generator that, if a predetermined frequency decrease that requires PFR has occurred in the power system, calculates a marginal active power based on the difference between a predetermined rotational speed lower limit value, which is obtained by providing the parallel-off rotational speed with a predetermined margin, and a measured value of the shaft rotational speed, and generates an active power command value based on the marginal active power.

Abstract: A wind turbine generator, an active damping method thereof, and a windmill tower in which vibrations of the wind turbine generator itself or the windmill tower can be reduced at low cost are provided. The acceleration due to vibrations of a nacelle is detected with an accelerometer attached to the nacelle. In an active damping unit, a pitch angle of windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command ??* for damping. On the other hand, in a pitch-angle control unit, a pitch angle of the windmill blades for controlling the output to be a predetermined value is calculated, and the pitch angle is output as a blade-pitch-angle command ?* for output control. The blade-pitch-angle command ??* for damping is combined with the blade-pitch-angle command ?* for output control using a subtracter.

Abstract: A wind turbine generator, an active damping method thereof, and a windmill tower in which vibrations of the wind turbine generator itself or the windmill tower can be reduced at low cost are provided. The acceleration due to vibrations of a nacelle is detected with an accelerometer attached to the nacelle. In an active damping unit, a pitch angle of windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command ??* for damping. On the other hand, in a pitch-angle control unit, a pitch angle of the windmill blades for controlling the output to be a predetermined value is calculated, and the pitch angle is output as a blade-pitch-angle command ?* for output control. The blade-pitch-angle command ??* for damping is combined with the blade-pitch-angle command ?* for output control using a subtracter.

Abstract: Provided is a wind power generation system intending to suppress an increase of torque when a voltage in a utility grid is restored, and to reduce a load to devices due to the torque. The blade control unit controls the pitch angle of the wind turbine blades such that a rotation speed of the power generator becomes equal to or greater than a synchronous rotation speed when the power control unit de-actuates the operations of the converter and the inverter, and controls the pitch angle of the wind turbine blades such that the pitch angle matches a target pitch angle that is determined based on one of a wind speed, a rotation speed of the power generator, and a requested output power when the power control unit re-actuates the operations of the converter and the inverter.

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: A wind turbine generator, an active damping method thereof, and a windmill tower in which vibrations of the wind turbine generator itself or the windmill tower can be reduced at low cost are provided. The acceleration due to vibrations of a nacelle is detected with an accelerometer attached to the nacelle. In an active damping unit, a pitch angle of windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command ??* for damping. On the other hand, in a pitch-angle control unit, a pitch angle of the windmill blades for controlling the output to be a predetermined value is calculated, and the pitch angle is output as a blade-pitch-angle command ?* for output control. The blade-pitch-angle command ??* for damping is combined with the blade-pitch-angle command ?* for output control using a subtracter.

Abstract: The object is to reduce an output fluctuation in an interconnection node. Provided is an operation control method of a wind power generation system including a step of obtaining the output data of each wind turbine, a step of determining a correlation between output fluctuations of adjacent wind turbines by using output data, and a step of shifting, if a strong correlation is exhibited, a phase of output fluctuation of either one of the adjacent wind turbines by a period at which the strong correlation is exhibited.

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: An object is to provide a wind turbine generator that is capable of continuously operating an auxiliary unit even when a grid fault occurs. Provided is a wind turbine generator including an auxiliary-unit breaker provided in a power line that connects an auxiliary unit to a power grid, wherein the auxiliary-unit breaker has a current-resisting capacity within a range that tolerates a current that flows in a low-voltage event and does not exceed a tolerable current of a motor provided in the auxiliary unit.

Abstract: When a rotor is suddenly accelerated, a wind turbine generator is stopped without exerting a mechanical impact on both a tower and wind turbine blades. When the rotational speed of a wind turbine rotor is suddenly accelerated, a control unit controls the driving speed of the blades so as to change from high speed to low speed, stepwise or continuously, when a pitch-angle control unit drives the pitch angle of the blades to a feathering side.

Abstract: A wind-turbine control system is provided for each of a plurality of wind turbine generators constituting a wind farm, sends wind-turbine data about a controlled wind turbine generator to the wind-turbine control systems provided for the other wind turbine generators, and receives wind-turbine data about the other wind turbine generators from the wind-turbine control systems provided for the other wind turbine generators. Then, the wind-turbine control system controls the controlled wind turbine generator based on the wind-turbine data about the controlled wind turbine generator and the wind-turbine data about the other wind turbine generators. Therefore, the control of the wind turbine generators constituting the wind farm can be changed more swiftly according to the operational condition of the wind farm.

Abstract: A wind turbine generator system includes: a wind turbine rotor including a blade having a variable pitch angle; a generator driven by the wind turbine rotor; and a control unit controlling the output power of the generator and the pitch angle of the blade in response to the rotational speed of the wind turbine rotor or the generator.

Abstract: A wind turbine generator, an active damping method thereof, and a windmill tower in which vibrations of the wind turbine generator itself or the windmill tower can be reduced at low cost are provided. The acceleration due to vibrations of a nacelle is detected with an accelerometer attached to the nacelle. In an active damping unit, a pitch angle of windmill blades for generating a thrust on the windmill blades so as to cancel out the vibrations of the nacelle is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command ??* for damping. On the other hand, in a pitch-angle control unit, a pitch angle of the windmill blades for controlling the output to be a predetermined value is calculated, and the pitch angle is output as a blade-pitch-angle command ?* for output control. The blade-pitch-angle command ??* for damping is combined with the blade-pitch-angle command ?* for output control using a subtracter.

Abstract: An object is to improve the accuracy of reactive power adjustment. Reactive-power command values corresponding to individual wind turbines are determined by correcting a predetermined reactive-power command value for an interconnection node A using reactive power correction levels set for the individual wind turbines.