Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

# Method for Speed Control for a Wind Turbine

IP.com Disclosure Number: IPCOM000189500D
Original Publication Date: 2009-Nov-23
Included in the Prior Art Database: 2009-Nov-23
Document File: 2 page(s) / 70K

Siemens

## Related People

Juergen Carstens: CONTACT

## Abstract

In a mode of below rated power, the speed of wind turbines is controlled by adjusting the power. Under above rated power, the power is kept constant and the speed is controlled by the blade pitch angle. This requires a strategy to switch between controlling the speed by the power and by the blade pitch angle. The strategy has to meet following requirements: - The speed has to be the same if it is controlled by power or by pitch angle. - The pitch angle should be in optimal position until the power output is equal to rated input. Currently, this problem is solved by switching the controllers on and off. This means that the controller is either in a mode where the speed is controlled by the power or it is in a mode where the speed is controlled by the pitch angle.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 62% of the total text.

Page 1 of 2

Method for Speed Control for a Wind Turbine

Idea: Per Egedal, DK-Brande

In a mode of below rated power, the speed of wind turbines is controlled by adjusting the power. Under above rated power, the power is kept constant and the speed is controlled by the blade pitch angle. This requires a strategy to switch between controlling the speed by the power and by the blade pitch angle. The strategy has to meet following requirements:

- The speed has to be the same if it is controlled by power or by pitch angle.

- The pitch angle should be in optimal position until the power output is equal to rated input.

Currently, this problem is solved by switching the controllers on and off. This means that the controller is either in a mode where the speed is controlled by the power or it is in a mode where the speed is controlled by the pitch angle.

Now, the below and above rated power problem is solved by using cascade coupled controllers. The power controller and the pitch controller are activated constantly, but their speed references are varied by a master controller to assure the speed near to the master speed reference.

The proposed cascade coupled controllers are shown in figure 1. A Speed Master Controller is controlling the speed by adjusting the speed references to the two slave controllers. The output from the Speed Master Controller can be called Sp...