Wind Turbine Controller Starting Speed Above Critical Resonance
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Solution Overview
Problem
Wind turbines face inefficiencies and increased loading when operating near critical rotation speeds that excite the tower's natural frequency, particularly under turbulent conditions, leading to reduced output and potential damage.
Innovation Solution
Defining a starting rotation speed for wind turbines based on the tower's natural frequency and turbulence intensity, ensuring it lies above the critical speed to avoid excitation, and adjusting rotor blade settings to optimize aerodynamic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wind turbine operates near critical rotation speeds to maximize power generation, then productivity is improved, but the tower experiences increased loading and potential damage due to resonance
Solution Approach 1:
The controller pre-determines a starting rotation speed that is already above the critical rotation speed based on tower natural frequency calculations. This preliminary action ensures the rotor never enters the critical speed range during startup, preventing resonance-induced tower loading before it can occur.
Solution Approach 2:
The patent changes the operating parameter (rotation speed) by establishing a new starting rotation speed threshold that is higher than the conventional value. This parameter change shifts the entire operating range above the critical speed, eliminating resonance conditions while maintaining power generation capability.
2Object-affected harmful factors
If the wind turbine increases starting rotation speed to avoid critical speeds, then tower loading is reduced, but starting wind speed requirement increases
Solution Approach 1:
The controller calculates and sets the starting rotation speed in advance based on the tower's natural frequency characteristics before the turbine begins operation. This preliminary configuration allows the turbine to skip the critical speed range entirely, reducing tower loading despite the higher starting wind speed requirement.
3Productivity
If the wind turbine passes through critical rotation speed range rapidly, then productivity is maintained, but measurement precision of the critical speed detection is required
Solution Approach 1:
The patent introduces an intermediary calculation approach where the critical rotation speed is determined indirectly through tower natural frequency characteristics rather than direct measurement. The controller uses the known relationship between tower natural frequency and critical rotor speed to establish a safe operating threshold without requiring precise real-time speed detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances operational efficiency, increases starting wind speed, and reduces loading by maintaining operation above critical rotation speeds, thereby improving overall yield and minimizing tower loading.
Implementation Method 1
an aerodynamic rotor 106 which can be operated at a variable rotor speed. The rotor speed can also simply be referred to as the rotation speed. The aerodynamic rotor has a plurality of rotor blades 108
Implementation Method 2
A generator 108 for generating an electrical output power is also provided, and the generator is driven by the aerodynamic rotor during operation
Implementation Method 3
The rotor blades can be adjusted in respect of their angle of attack in relation to the wind
Implementation Method 4
the rotation of an aerodynamic rotor can excite a natural frequency of a wind turbine or a natural frequency of a tower of the wind turbine depending on the rotor speed
Implementation Method 5
a natural frequency of a tower of the wind turbine depending on the rotor speed
Data Source
AI summary
A wind turbine includes a tower, an aerodynamic rotor operable at a variable rotor speed and having a plurality of rotor blades each having an adjustable rotor blade setting angle and a generator for generating an electrical output power. An operating characteristic curve is prespecified for operating the wind turbine. The operating characteristic curve indicates a relationship between the rotor speed and the output power. A controller is provided, which sets the output power in accordance with the operating characteristic curve depending on the rotor speed. The the operating characteristic curve has a starting rotation speed to which the rotor speed increases as soon as the wind turbine starts when a sufficient wind speed is reached. The starting rotation speed is defined depending on a tower natural frequency of the wind turbine and/or depending on a detected turbulence measure of the prevailing wind.