Wind Turbine Clutch Control for Rotor Stalling Prevention
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Solution Overview
Problem
Wind power generation systems face low efficiency due to mechanical losses and rotor stalling caused by cogging torque and generation load, especially at low wind speeds.
Innovation Solution
A wind power generation method and system that intermittently connects and disconnects a generator to a rotor via a clutch, idling the rotor at low wind speeds and reconnecting when the rotor reaches a specific peripheral speed to avoid stalling, using a control device with a rotational speed detector and anemometer to manage wind speed and rotation speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the generator is continuously connected to the rotor, then power generation can be maintained, but the rotor stalls due to cogging torque and power generation load at low wind speeds
Solution Approach 1:
The clutch is operated periodically to connect and disconnect the generator from the rotor based on wind speed conditions. At low wind speeds, the clutch disconnects to allow the rotor to idle freely without generator load. When wind speed increases sufficiently, the clutch connects to enable power generation. This periodic connection and disconnection prevents rotor stalling while maximizing power generation opportunities.
2Reliability
If the clutch is disconnected to idle the rotor at low wind speeds, then rotor stalling is prevented, but power generation time is reduced
Solution Approach 1:
The system continuously monitors wind speed and rotor rotation speed to determine the optimal timing for clutch operation. When wind speed exceeds a predetermined threshold and the rotor reaches sufficient rotation speed, the control device activates the clutch to connect the generator. This feedback mechanism ensures the clutch is engaged only under favorable wind conditions, maximizing power generation while preventing stalling during unfavorable conditions.
3Extent of automation
If electric control means are used to manage the clutch, then precise control of power generation is achieved, but system cost and complexity increase
Solution Approach 1:
The system utilizes the rotor's own rotational inertia and the natural wind conditions to control clutch operation. The rotor's momentum during idle rotation and its acceleration under wind force provide natural feedback signals that simplify the control logic. The control device monitors these self-generated signals to determine when to engage or disengage the clutch, reducing the need for complex external control systems while maintaining precise control.
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 power generation efficiency by preventing rotor stalling and reducing the time of power generation stoppages, allowing the rotor to rapidly accelerate when wind conditions improve, while also reducing costs by eliminating the need for electric control means in some configurations.
Implementation Method 1
the lift (thrust) generated in the blade increases due to the action of the inwardly tilted parts at the upper and lower ends of the blade and by the Coanda effect, the rotor rotates while accelerating to the peripheral speed exceeding the wind speed
Implementation Method 2
a clutch which is provided between the main shaft and the generator and is capable of interrupting transmission of power between the main shaft and the generator
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Provided is a wind power generation method capable of efficiently generating electricity while preventing beforehand a rotor from stalling. A generator 3 is connected to a vertical main shaft 5 of a rotor 2 via a clutch 9. The method comprising following steps to be repeated; disconnecting the clutch when the rotor is rotating at or below a predetermined average wind speed, to idle the rotor, connecting the clutch for generating power by the generator when the rotor reached a specific peripheral speed or rotational speed, disconnecting the clutch again when the rotor is rotating at or below the predetermined average wind speed to idle the rotor until reach the specific value of peripheral speed or rotational speed, and connecting the clutch again for generating power by the generator when the rotor reached the specific value.