Wind Turbine Characteristic Curve Adjustment for Slewing-Load Limits
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Solution Overview
Problem
Wind turbines face limitations in increasing rotor speed to enhance power generation due to the risk of exceeding permissible slewing loads, which are caused by frequent load changes during high rotational speeds, leading to potential mechanical strain and reduced power output.
Innovation Solution
Adjusting the operating characteristic curve of wind turbines to allow variable rotor speeds, with separate sections for lower and higher speeds, where higher speeds in one section are compensated by lower speeds in another to maintain a consistent total number of rotor revolutions, thus increasing power output while adhering to load limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If rotor speed is increased to enhance power generation, then power output is improved, but slewing loads exceed permissible levels
Solution Approach 1:
The operating characteristic curve is made dynamically adjustable through two distinct sections: a first section (up to rated wind speed) that limits rotor speed to reduce slewing loads, and a second section (above rated wind speed) that allows higher rotor speeds to increase power output. This dynamic segmentation resolves the contradiction by applying different speed strategies to different operating conditions.
Solution Approach 2:
The invention changes the parameter of rotor speed limits based on wind speed conditions. By defining different maximum rotor speeds for the first operating range (below rated wind speed) and second operating range (above rated wind speed), the system optimizes power generation while maintaining slewing loads within permissible limits through parameter adaptation.
2Productivity
If rotor speed is increased to increase power generation, then energy yield is improved, but the number of load cycles increases causing mechanical strain
Solution Approach 1:
The operating characteristic curve is divided into two dynamic sections that adapt rotor speed limits to wind speed conditions. The first section maintains lower speeds to protect mechanical components during normal operation, while the second section permits higher speeds to capture additional energy during high wind conditions, thus balancing productivity and reliability.
Solution Approach 2:
Different maximum rotor speed parameters are applied based on operating range: a first maximum speed for winds below rated speed and a second higher maximum speed for winds above rated speed. This parameter change strategy increases annual energy production while preventing excessive load cycles that would compromise mechanical durability.
3Power
If operating characteristic curve is adjusted to allow higher rotor speeds, then power generation is improved, but load limits may be exceeded
Solution Approach 1:
The operating characteristic curve is segmented into two distinct sections with different rotor speed characteristics. The first section (partial load range) maintains lower speeds to stay within load limits, while the second section (full load range) allows higher speeds to increase power generation. This segmentation enables the system to optimize power output without exceeding permissible load limits in either operating range.
Solution Approach 2:
The invention implements parameter changes by defining different maximum rotor speeds for different operating ranges. In the first range (below rated wind speed), a conservative speed limit protects against exceeding load limits. In the second range (above rated wind speed), a higher speed parameter enables increased power generation while the system operates near but within permissible load boundaries.
Data Source
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AI summary
The invention relates to a method for adjusting an operating characteristic curve (302) of a wind turbine (100), wherein the wind turbine (100) has a rotor (106) with rotor blades (108) whose blade angle is adjustable, the rotor (106) can be operated at a variable rotor speed (n), an operating characteristic curve (302) is used to control the wind turbine (100) which describes a relationship between the rotor speed (n) and at least one operating parameter (P), wherein the operating characteristic curve (302) has a first characteristic curve section with a first speed range (A1), and a second characteristic curve section with a second speed range (A2), wherein the first speed range (A1) has lower speeds (n) than the second speed range (A2), and the operating characteristic curve (302) is adjusted such that the values of the operating parameter (P) of the first characteristic curve section are increased.and values of the operating parameter (P) of the second characteristic curve section are changed towards higher rotational speeds, and that the adjustment of the operating characteristic curve (302) is carried out in such a way that an expected total number of rotations of the rotor (106) over a given operating time of the wind turbine (100) remains approximately the same.