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 (13) is detected with an accelerometer (17) attached to the nacelle (13). In an active damping unit (20), a pitch angle of windmill blades (12) for generating a thrust on the windmill blades (12) so as to cancel out the vibrations of the nacelle (13) 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 (30), a pitch angle of the windmill blades (12) 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 (40).

Abstract: A diesel engine system includes a diesel engine, a throttle valve, an EGR (Exhaust Gas Recirculation) path, an EGR valve and a controller. The throttle valve controls a flow rate of intake air to the diesel engine. Exhaust gas is recirculated along the EGR path from an exhaust port to an intake port of the diesel engine. The EGR valve controls a flow rate of the exhaust gas. The controller controls the throttle valve and the EGR valve such that an opening of the throttle valve decreases and an opening of the EGR valve increases when a load of the diesel engine increases. The controller controls the EGR valve such that the opening of the EGR valve increases after the opening of the EGR valve is held constant for a first predetermined holding time.

Abstract: A blade-pitch-angle control device includes a memory unit in which predetermined parameters that affect the load fluctuation of blades, azimuth angles, and pitch-angle command values are stored in association with each other; an azimuth-angle detecting unit that detects the azimuth angle of each of the blades; a parameter-detecting unit that detects the predetermined parameters; a command-value receiving unit that receives pitch-angle command values for each of the blades from the memory unit, the pitch-angle command values being selected on the basis of the azimuth angle of each blade detected by the azimuth-angle detecting unit and the predetermined parameters detected by the parameter-detecting unit; and a pitch-angle-control command-value generating unit that generates pitch-angle-control command values for individually controlling the pitch-angle of each blade on the basis of the pitch-angle command values and a common-pitch-angle command value.