Variable-speed tail rotors for helicopters with variable-speed main rotors

Nonlinear L2 control of a laboratory helicopter with variable speed rotors

This paper considers the problem of a nonlinear L2-disturbance rejection design for a laboratory twin-rotor system. Since the rotor blades present fixed angle of attack, control is achieved by using the rotor speeds as control variables. This mechanical device features highly nonlinear strongly coupled dynamics. The control is developed considering a reduced order model of the rotors obtained b...

Intelligent Control for the Variable-Speed Variable-Pitch Wind Energy System

In this paper, a new type of multi-variable compensation control method for the wind energy conversion systems (WECS) is presented. Based on wind energy conversion systems, combining artificial neural network (ANN) control and PID, a new type of PID NN intelligent controller for steady state torque of the wind generator is designed, by which the steady state torque output is regulated to track ...

Dynamic Analysis of Moving Cables with Variable Tension and Variable Speed

Dynamic Analysis of an axially moving cable with time dependent tension and velocity isstudied in this paper. Tension force and the moving speed are assumed to be harmonic.It is found that there exists a specific value of speed in which natural frequency of the system approacheszero. This specific speed for such a critical condition is called critical speed and it will be proved thatincreasing ...

High Speed Rotors on Gas Bearings: Design and Experimental Characterization

Variable Speed Wind Turbine

Wind energy is currently the fastest-growing renewable source of energy in India; India is a key market for the wind industry, presenting substantial opportunities for both the international and domestic players. In India the research is carried out on wind energy utilization on big ways .There are still many unsolved challenges in expanding wind power, and there are numerous problems of intere...