US 8,044,529 B2 · Method of damping tower vibrations of a wind turbine and control system for wind turbines

Abstract

A control system for a wind turbine is provided. A pitch-control unit establishes a pitch-reference signal representing a pitch to be set by the pitch-actuator system. A rotor-speed input receives a signal representing a speed of the rotor. A speed-reference input receives a speed-reference signal for the rotor speed. An inclination-signal input receives a signal representing a tower inclination. A pitch-reference output outputs the pitch reference signal. A modification unit is connected to the speed-reference input to receive the speed-reference signal and connected to the inclination-signal input to receive the inclination signal. The modification unit establishes a modification signal based on the inclination signal, to modify the speed-reference signal via the modification signal, and to output a modified-speed-reference signal. The pitch-control unit connected to the modification unit to receive the modified-speed-reference signal and establish the pitch-reference value at least based on the difference between the modified-speed-reference and the rotor-speed signals.

Claims21

Dependent claims

A method of damping tower vibrations of a wind turbine which is equipped with rotor blades, a pitch controller and a pitch actuator system, by controlling the pitch angle of the rotor blades, the method comprising:

providing a speed reference value for an actual rotor speed;
providing a rotor speed value representing a speed reference speed of the rotor speed;
and
establishing a modification value representing a modification to be done to the rotor speed value for taking into account the tower vibrations;
modifying the speed reference value with the modification value to establish a modified speed reference value;
determining a pitch reference value representing a pitch to be set by the pitch actuator system, the pitch reference value based on at least a difference between the modified speed reference value and the rotor speed value;
and
controlling the pitch angle of the rotor blades according to the pitch reference value.

5 more elements

A control system for use in a wind turbine with rotor blades and a pitch actuator system, the control system comprising:

a rotor speed input receives a rotor speed signal representing an actual speed of the rotor;
a speed reference input receives a speed reference signal for a rotor speed;
an inclination signal input receives a signal representing an inclination of a tower of the wind turbine;
a pitch reference output for outputting the pitch reference signal;
a modification unit connected to the speed reference input and to the inclination signal input, the modification unit establishes a modification signal based the inclination signal, modifies the speed reference signal via the modification signal, and outputs a modified speed reference signal;
and
a first subtraction unit connected to the modification unit and to the rotor speed input, the first subtraction unit to establish a speed difference signal representing the difference between the rotor speed signal and the modified speed reference signal;
and
a pitch control unit to establish a pitch reference signal representing a pitch to be set by the pitch actuator system, the pitch control unit connected to the first subtraction unit to receive the speed difference signal and the pitch control unit to establish the pitch reference value at least based on of the speed difference signal.

6 more elements

Dependencies are inferred from the claim text.

Method of damping tower vibrations of a wind turbine and control system for wind turbines

Life of this patent

Method of damping tower vibrations of a wind turbine and control system for wind turbines

Life of this patent

Abstract

Claims21