Abstract: A power generation system includes: a prime mover; a magnetic gear generator configured to be driven by an input from the prime mover to generate power; a power converter connected to the magnetic gear generator; an operation mode switch unit configured to switch an operation mode of the magnetic gear generator to a step-out avoidance mode in response to that a step-out parameter indicating a risk of step-out of the magnetic gear generator exceeds a prescribed allowable range; and a reduction command unit configured to give the prime mover an input reduction command to reduce the input from the prime mover and configured to give the power converter a torque reduction command to reduce a generator torque of the magnetic gear generator, in the step-out avoidance mode.

Abstract: The present electric power generation control device includes: an event detection unit which detects an event attributable to a deterioration in the balance between a torque input to a generator and an effective power output by the generator, the deterioration being caused by a reduction in a set value of the effective power received from the generator by an electric power converter when the electric power converter has detected a failure necessitating interruption of electric power transmission from the generator by a direct-current (DC) power transmission unit, the DC power transmission unit transmitting DC power, the electric power converter connecting a generator to the DC power transmission unit; and a torque command reduction unit which causes a reduction in a torque command to a motor when the event detection unit has detected the event attributable to the deterioration in the balance, the motor outputting the torque input to the generator.

Abstract: A method of controlling a floating-body wind turbine power generating apparatus including a wind turbine generator disposed on a floating body includes a pitch-angle increasing step of increasing a pitch angle of a blade of the wind turbine generator when the wind turbine generator is stopped, so that an aerodynamic braking force is applied to a rotor of the wind turbine generator. In the pitch-angle increasing step, a first change rate of the pitch angle of the blade in a first period during which the wind turbine generator is in an inclining motion toward an upwind side from a vertical direction due to sway of the floating body, is smaller than a second change rate of the pitch angle of the blade in a second period during which the wind turbine generator is in an inclining motion toward a downwind side from the vertical direction due to the sway of the floating body.

Abstract: A method of controlling a floating-body wind turbine power generating apparatus including a wind turbine generator disposed on a floating body includes a pitch-angle increasing step of increasing a pitch angle of a blade of the wind turbine generator when the wind turbine generator is stopped, so that an aerodynamic braking force is applied to a rotor of the wind turbine generator. In the pitch-angle increasing step, a first change rate of the pitch angle of the blade in a first period during which the wind turbine generator is in an inclining motion toward an upwind side from a vertical direction due to sway of the floating body, is smaller than a second change rate of the pitch angle of the blade in a second period during which the wind turbine generator is in an inclining motion toward a downwind side from the vertical direction due to the sway of the floating body.

Abstract: A method of controlling a floating-body wind turbine power generating apparatus including a wind turbine generator disposed on a floating body includes a pitch-angle increasing step of increasing a pitch angle of a blade of the wind turbine generator when the wind turbine generator is stopped, so that an aerodynamic braking force is applied to a rotor of the wind turbine generator. In the pitch-angle increasing step, a first change rate of the pitch angle of the blade in a first period during which the wind turbine generator is in an inclining motion toward an upwind side from a vertical direction due to sway of the floating body, is smaller than a second change rate of the pitch angle of the blade in a second period during which the wind turbine generator is in an inclining motion toward a downwind side from the vertical direction due to the sway of the floating body.

Abstract: The present electric power generation control device includes: an event detection unit which detects an event attributable to a deterioration in the balance between a torque input to a generator and an effective power output by the generator, the deterioration being caused by a reduction in a set value of the effective power received from the generator by an electric power converter when the electric power converter has detected a failure necessitating interruption of electric power transmission from the generator by a direct-current (DC) power transmission unit, the DC power transmission unit transmitting DC power, the electric power converter connecting a generator to the DC power transmission unit; and a torque command reduction unit which causes a reduction in a torque command to a motor when the event detection unit has detected the event attributable to the deterioration in the balance, the motor outputting the torque input to the generator.

Abstract: A power-converter controller is provided in a wind turbine generator which is interconnected to a utility grid and in which a generator generates electrical power by rotation of a rotor having blades. The power-converter controller includes a voltage sensor that measures a generator terminal voltage, resonance-component extracting sections that extract an electrical resonance component generated due to the interconnection from a measurement result measured by the voltage sensor, and a control section and a control section that control a current that flows to the utility grid so as to suppress the resonance component, on the basis of the resonance component extracted by the resonance-component extracting sections. Accordingly, the power-converter controller can more effectively suppress the resonance generated due to the interconnection of the wind turbine generator to the utility grid.

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: 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 method of controlling a floating-body wind turbine power generating apparatus including a wind turbine generator disposed on a floating body includes a pitch-angle increasing step of increasing a pitch angle of a blade of the wind turbine generator when the wind turbine generator is stopped, so that an aerodynamic braking force is applied to a rotor of the wind turbine generator. In the pitch-angle increasing step, a first change rate of the pitch angle of the blade in a first period during which the wind turbine generator is in an inclining motion toward an upwind side from a vertical direction due to sway of the floating body, is smaller than a second change rate of the pitch angle of the blade in a second period during which the wind turbine generator is in an inclining motion toward a downwind side from the vertical direction due to the sway of the floating body.

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 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: A wind power generation system is disclosed for suppressing 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 wind power generation system includes a blade control unit for controlling the pitch angle of the wind turbine blades such that the pitch angle matches a target pitch angle determined on the basis of at least 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 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: 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: 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: 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 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 is detected with an accelerometer attached to the nacelle. In an active damping unit, a pitch angle of windmill blades for generating a thrust is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command ??* for damping. In a pitch-angle control unit, a pitch angle of the windmill blades for controlling the output, 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. The pitch angle of the windmill blades is controlled on the basis of the resulting blade-pitch-angle command after combining.

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: 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 is detected with an accelerometer attached to the nacelle. In an active damping unit, a pitch angle of windmill blades for generating a thrust is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command ??* for damping. In a pitch-angle control unit, a pitch angle of the windmill blades for controlling the output, 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. The pitch angle of the windmill blades is controlled on the basis of the resulting blade-pitch-angle command after combining.