Rotational speed

About: Rotational speed is a research topic. Over the lifetime, 23327 publications have been published within this topic receiving 151696 citations. The topic is also known as: speed of revolution & revolution rate.

Wind turbine monitoring

Abstract: A method of monitoring the performance of a wind turbine (1) uses bending momentdata from strain sensors (4) in the turbine blades (2) to calculate rotational speed of the turbine (1), angular position of the turbine blades (2), drive torque and resultant load on the rotor (3). The method has the advantage that the inputs to the drive train of the wind turbine can be (5) measure directly.

Power output apparatus, vehicle equipped with power output apparatus, and control method of power output apparatus

Abstract: When a required speed ratio as a required value of a speed ratio between an engine and a driveshaft becomes equal to or less than a lower limit speed ratio that is not more than an n-th shift speed ratio during an n-th speed state of a transmission, a hybrid vehicle controls the engine, two motors, and the transmission to ensure output of power based on a torque demand to the driveshaft while performing an engine rotational speed adjustment of making a rotational speed of the engine equal to a shift rotational speed corresponding to an upper side shift speed ratio or an effective shift speed ratio and a shift from an n-th speed state to an (n+1)-th speed state.

Apparatus and method for controlling operation of elevator in power failure

Abstract: An apparatus for controlling an operation of an elevator includes a power supply unit for detecting whether the main power supply was supplied including a charger and for outputting a predetermined control signal, an operation control unit for receiving the control signal from the direct current power supply unit and a demand control signal inputted by a user and for outputting a speed control signal and a load compensation signal so as to control the elevator system, a power consumption detector for computing a power consumption of the alternating current motor, a speed limiter for limiting a speed of the motor upon receipt of the alternating current motor speed signal from the speed detector and the power consumption of the motor computed by the power consumption detector, and a speed control unit for controlling a rotational speed of the alternating current motor upon receipt of the load compensation signal and the control signal from the speed limiter. By having such construction, the discharge amount of a charged power supply is minimized when an elevator is operated on the charged power supply in an emergency and an over current is prevented.

Optimised control approach for frequency-control contribution of variable speed wind turbines

Abstract: This study proposes a novel control strategy for the provision of an active power reserve for variable-speed wind turbines. The proposed control strategy aims at maximising the rotational kinetic energy by jointly optimising the rotational speed and the pitch angle using differential evolution. The optimisation process takes into account the given frequency support power-reserve margin. Based on the optimisation results, a novel controller strategy is proposed and compared with other existing approaches. This comparison reveals that relative to existing methods at the same de-loaded power, the proposed method yields more rotational kinetic energy released into the system in the event of frequency deviations, thus increasing the frequency stability of the power system.