Method for operating a wind turbine

Patent metadata

Field	Value
Publication number	US-10584679-B2
Application number	US-201615572056-A
Country	US
Kind code	B2
Filing date	Apr 20, 2016
Priority date	May 7, 2015
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A method for operating a wind turbine (WEA), which has a generator for supplying electric power to an electric supply grid, is provided. After being operated in a first operating state with a first power output and a first rotational speed, the wind turbine is set to a second operating state with a second power output and a second rotational speed. In order to set the wind turbine to the second operating state, an aerodynamic power output which is available for supply is determined, a target rotational speed is determined from the available output, and a target output to be set for the generator is specified from the target rotational speed.

First claim

The invention claimed is:

1. A method for operating a wind power installation, comprising:
feeding, by a generator, electrical power into an electrical supply network with a first operating state with a first power output and a first rotational speed,
temporarily increasing the first power output during the first operating state beyond an output power that the wind power installation is able to generate based on prevailing wind conditions, and
controlling, by a controller, a change to a second operating state with a second power output and a second rotational speed, controlling the change to the second operating state including:
receiving, by a state observer, a rotational speed of the generator and a mechanical torque of the generator, the rotational speed and the mechanical torque being observed state variables,
determining, by the state observer, an available aerodynamic power for feeding using the rotational speed of the generator and power fed into an intermediate electrical storage,
determining a setpoint rotational speed using the available aerodynamic power,
determining a setpoint power using the setpoint rotational speed, and
using the setpoint power to adjust the generator.

2. The method according to claim 1 , wherein the state observer used for determining the available aerodynamic power is defined by a structure of:

[

ω
^

.

T
^

.

mech

]

=

[

-

k
ω

1
J

-

k
T

0

]

⁡

[

ω
^

T
^

mech

]

+

[

k
ω

-

1
J

k
T

0

]

⁡

[

ω

T
el

]

in which
J denotes a combined moment of inertia of a rotor and the generator,
ω is the rotational speed of the generator,
k ω and k T are parameters for influencing a dynamic response of the state observer,
T el is an electrical torque that is determined as a ratio of the power fed into the intermediate electrical storage and the rotational speed (ω), and
T mech denotes the mechanical torque of the rotor and the generator, wherein the rotational speed of the generator is an actual or observed rotational speed of the generator and the mechanical torque of the rotor is an observed mechanical torque of the rotor.

3. The method according to claim 2 , comprising:
determining, by a regulator, the setpoint power using the available aerodynamic power and the actual rotational speed of the generator.

4. The method according to claim 1 , comprising:
determining the setpoint rotational speed as a function of the aerodynamic available power from a rotational speed and power characteristic curve.

5. The method according to claim 2 , comprising:
determining, by a regulator, a difference between the setpoint rotational speed and the actual rotational speed,
determining, by the regulator, a differential torque between the observed mechanical torque and the electrical torque using a regulating algorithm,
determining a setpoint torque as a sum of the differential torque and the observed mechanical torque, and
determining the setpoint power as a product of the setpoint torque and the actual rotational speed.

6. A controller configured to determine an available aerodynamic power of a wind power installation including a generator, wherein the controller is configured to:
control a change from a first operating state in which the generator feeds electrical power into an electrical supply network with a first operating state with a first power output and a first rotational speed, to a second operating state in which the generator feeds electrical power into the electrical supply network with a second power output and a second rotational speed, wherein the first power output during the first operating state is temporarily increased beyond an output power that the wind power installation is able to generate based on prevailing wind conditions, controlling the change to the second operating state including:
observing a rotational speed of the ge

Assignees

• Wobben Properties Gmbh

Inventors

• Engelken Sönke
• Mihov Nikolay
• Mendonca Angelo

Classifications

• F03D7/0276 Primary

  controlling rotor speed, e.g. variable speed · CPC title

• G05B19/042

  using digital processors (G05B19/05 takes precedence) · CPC title

• G05B2219/2619

  Wind turbines · CPC title

• F05B2270/1033

  Power (if explicitly mentioned) · CPC title

• F05B2270/101

  to control rotational speed (n) · CPC title