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.

Abstract: In a wind turbine generator, the rotation of the rotor is speeded up by a hydraulic pump and a hydraulic motor and is transferred to a synchronous generator. In a state in which the wind turbine generator is interconnected to a utility grid, and the synchronous generator reaches a synchronous speed, if no mechanical power is transferred to the synchronous generator, a wind-turbine control system operates the synchronous generator as a synchronous condenser, thus controlling the magnitude of the field current of the synchronous generator. Thus, the wind turbine generator can supply reactive power to the utility grid without adding new equipment, such as a reactive power compensator using a semiconductor switch.

Abstract: It is intended to provide a power generating apparatus of renewable energy type and an operation method of the power generating apparatus, which can achieve both variable speed operation and grid connection without a frequency converting circuit and which uses a hydraulic transmission. In the power generating apparatus of renewable energy type 1, renewable energy received via a blade 4 is transmitted to a synchronous generator 20 via a rotating shaft 8 and a hydraulic transmission 10. The synchronous generator 20 is driven by a hydraulic motor 14 of the hydraulic transmission 10 to generate power. The synchronous generator 20 is connected to a grid without a frequency converting circuit and the power generated by the synchronous generator 20 is supplied to the grid 50. The power generating apparatus 1 is also provided with a transmission controller 40 which controls the hydraulic transmission 10.

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: It is an object to stabilize a utility grid even when an unexpected fluctuation in the frequency of the utility grid occurs. A wind turbine generator includes a rotor that rotates by wind power, a generator that is driven by rotation of the rotor, and a control device that controls a power output of the generator to increase while a rotational speed of the generator decreases when a frequency of a utility grid becomes smaller than or equal to a predetermined rated frequency and when the rotational speed of the generator is greater than or equal to a first predetermined value. In this way, even when the frequency of the utility grid fluctuates, the frequency fluctuation can be suppressed, and the utility grid can be stabilized.

Abstract: There are provided a TMD adjusted to damp vibration in a natural frequency of a wind turbine, an AVC adjusted to damp vibration in a variable frequency of turbulent wind flowing into the wind turbine and/or a frequency of a rotation speed of a wind-turbine blade, and a pitch-angle control portion provided with a correction portion which adjusts a damping frequency of the AVC. The AVC is configured to obtain the damping force by changing the pitch angle of the wind-turbine blade.

Abstract: Yaw control is performed such that a nacelle faces into an actual main wind direction.

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

Abstract: It is an object to enable stable operation of a wind turbine and to change a control parameter of the wind turbine at an appropriate timing. A dynamic-characteristics model of a wind turbine is identified for each of a plurality of ranges that are determined in accordance with wind speed, and the identified dynamic-characteristics model is monitored for each of the ranges.

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: It is an object to stabilize a utility grid even when an unexpected fluctuation in the frequency of the utility grid occurs. A wind turbine generator includes a rotor that rotates by wind power, a generator that is driven by rotation of the rotor, and a control device that controls a power output of the generator to increase while a rotational speed of the generator decreases when a frequency of a utility grid becomes smaller than or equal to a predetermined rated frequency and when the rotational speed of the generator is greater than or equal to a first predetermined value. In this way, even when the frequency of the utility grid fluctuates, the frequency fluctuation can be suppressed, and the utility grid can be stabilized.

Abstract: A method of controlling an operation of a wind power generation system provided with a plurality of wind turbines, in which output power of each wind turbine is supplied to an electric power system through a common interconnection node where output data of each wind turbine is obtained, where a periodic correlation between output fluctuations of adjacent wind turbines is determined by using the output data, the correlation is determined as a strong correlation when the correlation is more than two times greater than an average level of the correlation, and a phase of the output of either one of the adjacent wind turbines is shifted by a period of the strong correlation.

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

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 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: 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 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: An object is to rapidly recover from a voltage drop in a power grid. When the value of a grid voltage detected by a grid voltage detection unit has fluctuated so as to satisfy a condition set in advance for a reference value, a control device controls a wind turbine generator such that a reactive current corresponding to a required output current that is determined by an active current and the reactive current and that indicates an output level to a power grid on the basis of the detection result from the grid voltage detection unit is output to the power grid.