General Electric Company

Other

U.S. Windpower, Inc.

Zond Energy Systems, Inc.

Clipper Windpower Technology, Inc.

William E Holley

William L Erdman

Kevin L Cousineau

Amir S Mikhail

Craig Leonard Christenson

Leonardo Cesar Kammer

Kirk Gee Pierce

Arne Koerber

Charudatta Subhash Mehendale

Bharat S Bagepalli

Patrick Lee Jansen

Danian Zheng

Thomas Frank Fric

Jignesh Govindlal Gandhi

Gary Randall Barnes

Lawrence Donald Willey

Conner Brooks Shane

Ulrich Uphues

Eric Gebhardt

Xiongzhe Huang

James Patrick Francis Lyons

Corneliu Barbu

Timothy Botsford Cribbs

Lawrence Howes

John Noel Cunningham

Raveendra Penmatsa

An oar apparatus configured to remain submerged under water during the power stroke and the return stroke. The oar apparatus has a sheath and a shaft rotationally disposed within the sheath. An oar blade is affixed to the shaft, such that the oar blade is rotational relative to the sheath. The oar blade has a deployed orientation, in which the oar blade is substantially perpendicular to the movement direction of the vessel, and a feathered configuration, in which the oar blade is substantially parallel to the movement direction of the vessel. The oar blade is asymmetrical relative to the center axis of the shaft, such that resistance of the water exerted onto the oar blade creates a first moment urging the oar blade into the deployed orientation during the power stroke and a second moment urging the oar blade into the feathered orientation on the return stroke.

Oar apparatus having a pivoting oar blade

A system and method for reducing oscillation loads of a wind turbine induced by high turbulence and/or combined with other environmental conditions are provided. The method includes determining at least one wind parameter at the wind turbine; monitoring an operating condition of the wind turbine; determining, by a processor, a variance of at least one of the monitored operating condition or a plurality of the wind parameters, wherein the variance is indicative of an oscillation occurring at one or more wind turbine components; determining, by a processor, an operating set point based on the variance; and, operating the wind turbine based on the operating set point when the variance indicates that the oscillation has a frequency within a certain frequency band so as to modify the frequency, wherein the modified frequency is outside of the frequency band and reduces oscillation loads occurring at the one or more wind turbine components.

System and method for reducing oscillation loads of wind turbine

Methods are provided for controlling wind turbine loading. In one embodiment, a method includes the steps of determining a current thrust value for the wind turbine, calculating a thrust differential based on the current thrust value and a predetermined maximum thrust value, calculating a desired pitch offset value based on the thrust differential and a thrust sensitivity value, and adjusting a pitch of the wind turbine utilizing the pitch offset value.

Methods for controlling wind turbine loading

Wind turbines and methods for controlling wind turbine loading are provided. In one embodiment, a method includes the steps of determining a current wind speed. The method further includes determining a tip speed ratio and a pitch angle that maximize a power coefficient under at least one of the following conditions: a thrust value is less than or equal to a pre-established maximum thrust, a generator speed value is less than or equal to a pre-established maximum generator speed, or a generator torque is less than or equal to a pre-established maximum generator torque. The method further includes calculating a desired generator speed value based on the current wind speed and a tip speed ratio. The method further includes calculating a desired generator power value based on the desired generator speed value.

Wind turbines and methods for controlling wind turbine loading

A control system for a rotary machine is provided. The rotary machine has at least one rotating member and at least one substantially stationary member positioned such that a clearance gap is defined between a portion of the rotating member and a portion of the substantially stationary member. The control system includes at least one clearance gap dimension measurement apparatus and at least one clearance gap adjustment assembly. The adjustment assembly is coupled in electronic data communication with the measurement apparatus. The control system is configured to process a clearance gap dimension signal and modulate the clearance gap dimension.

Methods and apparatus for controlling rotary machines

A method for controlling a rotational speed of a rotor having at least one rotor blade, a rotor shaft, and an electrical generator coupled thereto. The method includes controlling a torque of the rotor shaft by controlling a torque of the electrical generator, alternating between changing an angle of pitch of the at least one rotor blade and maintaining the angle of pitch of the at least one rotor blade substantially constant, and maintaining a substantially constant rotational speed of the rotor during variable wind speeds above a predetermined rated wind speed.

Methods and apparatus for controlling rotational speed of a rotor

A variable speed system for use in systems, such as, for example, wind turbines, is described. The system comprises a wound rotor induction generator, a torque controller and a proportional, integral derivative (PID) pitch controller. The torque controller controls generator torque using field oriented control, and the PID controller performs pitch regulation based on generator rotor speed.

Variable speed wind turbine generator

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

Variable speed distributed drive train wind turbine system

A variable speed system for use in systems, such as, for example, wind turbines, is described. The system comprises a wound rotor induction generator, a torque controller and a proportional integral derivative (PID) pitch controller. The torque controller controls generator torque using field oriented control, and the PID controller performs pitch regulation based on generator rotor speed.

A controller and method is disclosed for operating a variable speed turbine to track wind speed fluctuations for high efficiency in conversion of wind energy to electrical energy. The controller of the invention controls the rotor speed in accordance with a wind speed supplied by a wind observer in order to approximately follow the varying wind speeds. A yaw angle error sensor senses the degree to which the turbine is misaligned with the wind. The wind observer predicts the average wind speed at a subsequent point in time. The average wind speed is applied to a parameter schedule to determine desired values for rotor speed and torque which are used by a rotor speed stabilizer to command a reference load torque. The load torque of the generator is controlled in accordance with the commanded load torque, and therefore the desired rotor speed is approximated. During operation, the wind speed prediction process is repeated at each subsequent time interval, and the load torque, and therefore rotor speed, is controlled accordingly. The wind observer calculates the aerodynamic torque and then calculates net torque. The wind speed is predicted as a function of the present (previously predicted) wind speed and correction terms including net torque, the yaw angle error, and the difference between the predicted and actual rotor speed. The wind observer is useful whenever the wind turbine rotor is turning, whether or not it is producing power.

Speed control system for a variable speed wind turbine

Growing community of inventors

Pleasanton, CA, United States of America

William E Holley