Multi-rotor turbine coordinated speed control for oscillation attenuation
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Solution Overview
Problem
Multi-rotor wind turbine systems face challenges in controlling multiple rotors to achieve optimum power production, particularly in attenuating oscillations caused by rotating unbalances that can excite structural resonances, limiting operation at critical rotation frequencies and affecting power generation efficiency.
Innovation Solution
A control system that coordinates the rotational speeds of wind turbine modules to manage the unbalance vectors, ensuring they remain out of phase or apply counteracting forces, thereby reducing oscillations in the support structure without limiting the system's operational freedom. This is achieved through a centralized and localized control strategy using sensors and processors to adjust rotor speeds and maintain target angular differences between unbalance vectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If each rotor is controlled individually to maximize power production, then power generation efficiency is improved, but oscillations of the support structure increase due to unbalance forces coinciding
Solution Approach 1:
The control systems of multiple wind turbine modules are merged into a coordinated control system that manages rotors as a group rather than individually. The control means coordinates rotational speeds across all rotors to achieve a target angular relationship between unbalance vectors, combining their effects to attenuate support structure oscillations while maintaining power production.
Solution Approach 2:
The unbalance forces that normally cause harmful oscillations are converted into a beneficial effect by coordinating rotor speeds to create counteracting forces. By controlling the angular relationship between unbalance vectors, the previously harmful coinciding forces become useful counterbalancing forces that reduce net oscillations on the support structure.
2Stability of the object's composition
If rotor speeds are coordinated to attenuate oscillations, then support structure stability is improved, but operational freedom is limited
Solution Approach 1:
The control system dynamically adjusts rotor speeds based on real-time operating conditions while maintaining the target angular relationship between unbalance vectors. Rather than fixing rotor speeds, the system continuously coordinates speed adjustments to achieve both oscillation attenuation and adaptability to varying wind conditions and power demands.
Solution Approach 2:
The system changes operational parameters (rotor speeds) within a coordinated framework to maintain both stability and adaptability. By allowing individual rotor speeds to vary while constraining their angular relationship, the system achieves operational flexibility without compromising support structure stability.
3Productivity
If rotors operate at critical rotation frequencies, then power production is maximized, but resonant oscillations increase causing fatigue
Solution Approach 1:
The control system uses unbalance forces from individual rotors as counterweights to each other. By coordinating rotor speeds to achieve specific angular relationships between unbalance vectors, the system creates counteracting forces that neutralize resonant oscillations, allowing operation at critical frequencies without excessive fatigue accumulation.
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
The solution effectively attenuates oscillations in the support structure, allowing operation at critical rotation frequencies, reducing fatigue, and maintaining power generation efficiency by ensuring that unbalance forces do not reinforce each other, thus extending the service life of the wind turbine installation.
Implementation Method 1
each rotor has an associated rotating unbalance that defines an unbalance vector
Implementation Method 2
the forces exerted on the support structure as a result of the rotating unbalances of the rotors are controlled
Implementation Method 3
oscillations of the support structure caused by the rotating unbalance of the rotors
Implementation Method 4
control means configured to coordinate the rotational speeds of the plurality of rotors to attenuate oscillations of the support structure
Data Source
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AI summary
A wind turbine system is described comprising a plurality of wind turbine modules, each including a rotor, mounted to a support structure including a tower. In use, each rotor has an associated rotating unbalance that defines an unbalance vector. The wind turbine system includes control means configured to coordinate the rotational speeds of the plurality of rotors to attenuate oscillations of the support structure caused by the rotating unbalance of the rotors. Also described is a method of controlling such a wind turbine system. The method comprises coordinating the rotational speeds of the plurality of rotors to attenuate oscillations of the support structure caused by the rotating unbalance of the rotors.