Blade pitch

About: Blade pitch is a research topic. Over the lifetime, 5321 publications have been published within this topic receiving 63134 citations.

Global Analysis of a Floating Wind Turbine Using an Aero-Hydro-Elastic Model: Part 1—Code Development and Case Study

Abstract: This paper describes the extension of a well proven state-of-the-art simulation tool for coupled floating structures to accommodate offshore wind turbine applications, both floating and fixed. All structural parts, i.e. rotor blades, hub, nacelle, tower, vessel and mooring system, are included in the finite element model of the complete system. The aerodynamic formulation is based on the blade element momentum theory. A control algorithm is used for regulation of blade pitch angle and electrical torque. The system response is calculated by nonlinear time domain analysis. This approach ensures dynamic equilibrium every time step and gives a proper time domain interaction between the blade dynamics, the mooring dynamics and the tower motions. The developed computer code provides a tool for efficient analysis of motions, support forces and power generation potential, as influenced by waves, wind, and current. Some key results from simulations with wind and wave loading are presented in the paper. The results are compared with results obtained with a rigid blade model and quasi-static model of the anchor lines. The modelled wind turbine is the NREL offshore 5-MW baseline wind turbine, specifications of which are publicly available. In the accompanying paper, Global Analysis of a Floating Wind Turbine Using an Aero-Hydro-Elastic Numerical Model. Part 2: Benchmark Study, results from the new analysis tool are benchmarked against results from other analysis tools.Copyright © 2011 by ASME

Condition monitoring system for wind turbine generator and method for operating wind turbine generator

Abstract: A wind turbine generator condition monitoring system (200) includes a plurality of rotor shaft angular velocity sensors (206/208) The system also includes at least one processor (216) coupled to the plurality of rotor shaft velocity sensors The at least one processor is programmed to determine a difference between each of the plurality of rotor shaft angular velocity sensors of at least one of an angular displacement, an angular velocity, and an angular acceleration of the rotor shaft An output of the at least one processor including at least one of a wind turbine generator yaw orientation signal (336) and a wind turbine generator blade pitch orientation signal (336)

Method and apparatus for bucket natural frequency tuning

Abstract: A method of modifying a rotor blade, and a rotor blade are provided. The rotor blade is for a steam turbine and it is modified to facilitate altering a natural vibratory frequency of the rotor blade, the rotor blade includes a leading edge, a trailing edge, a first sidewall, and a second sidewall, wherein the first and second sidewalls are connected axially at the leading and trailing edges, and the sidewalls extending radially between a rotor blade root to a rotor blade tip. The method includes determining a vibratory resonance condition of the rotor blade and forming a blade extension between the rotor blade root and the rotor blade tip that alters the determined resonance condition.

Alleviation of unbalanced rotor loads by single blade controllers

Abstract: A novel approach to reducing the unbalance rotor loads by pitch control is presented in this paper. Each blade has its own actuator, sensors and controller. These localised blade control systems operate in isolation without need of communication with each other. This single blade control approach to regulation of unbalanced rotor loads has several advantages including being straightforward to design and easy to tune. Furthermore, it does not affect the operation of the central controller and the latter need not be re-designed when used in conjunction with the single blade controllers. Their performance is assessed using BLADED simulations.

Rotor blade pitch control

Abstract: A mechanical independent blade control (MIBC) mechanism for controlling the pitch of each of the blades of a rotor blade system or a main rotor of a rotor aircraft independently of the other blades includes a plurality of actuators disposed in the fuselage below the hub of the rotor, each being operable to selectively control the pitch of an associated one of the blades independently of the other blades, and a plurality of mechanical linkages disposed within the annulus of the rotor mast, each coupled between a blade and an actuator and operable to transmit a force output by the actuator to a pitch horn fixed to an inner end of the associated blade. The mechanism enables the direction of pitch of each blade to be changed more than twice during one revolution of the rotor.