Multirotor Wind Turbine Self-Yawing Stability

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Solution Overview

Problem

Multirotor wind turbines face instability and reduced energy production under turbulent wind conditions due to sudden 'flipping' of self-yawing mechanisms, which introduces undesirable loads and requires costly active yaw systems and reinforced towers.

Innovation Solution

The arrangement of energy generating units with their centers of gravity positioned behind and at specific distances relative to the tower structure ensures stable self-yawing, balancing torque from gravity and rotation, eliminating the need for active yaw mechanisms and reducing tower diameter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional self-yawing mechanisms are used, then the wind turbine can orient rotors into the wind under normal conditions, but under turbulent wind conditions the mechanism may suddenly flip 180 degrees causing undesirable loads and reduced energy production

Engineering Contradiction:

Improveself-yawing reliabilityVSAvoidundesirable loads from flipping

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional self-yawing approach by positioning the center of gravity behind the tower structure rather than in front. This inversion changes the stability characteristics so that the wind turbine resists sudden flipping while maintaining reliable self-yawing capability under turbulent wind conditions

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the critical parameter of center of gravity position from its conventional location to a position behind the tower structure at a specific distance. This parameter change fundamentally alters the yawing behavior to prevent harmful flipping while maintaining reliable orientation capability

Inventive Principle:

Principle #35Parameter changes

2Reliability

If active yaw systems are used to prevent flipping, then self-yawing reliability improves, but device complexity and manufacturing costs increase

Engineering Contradiction:

Improveself-yawing reliabilityVSAvoidyaw system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent enables the wind turbine to self-regulate its yaw orientation through the strategically positioned center of gravity behind the tower. This self-service mechanism eliminates the need for complex active yaw systems with motors and controllers, reducing device complexity while maintaining reliability

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

By inverting the center of gravity position, the patent creates a passive stability mechanism that naturally prevents flipping without requiring active control systems, thereby reducing device complexity while improving reliability

Inventive Principle:

Principle #13The other way round (Inversion)

3Strength

If reinforced tower structures are used to handle flipping loads, then structural strength improves, but weight and manufacturing costs increase

Engineering Contradiction:

Improvetower structure strengthVSAvoidtower structure weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The wind turbine's own center of gravity positioning creates a self-stabilizing effect that prevents harmful flipping loads. This eliminates the need for reinforced tower structures, reducing both weight and manufacturing costs while maintaining structural integrity

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent converts the potentially harmful effect of offset center of gravity into a beneficial stabilizing force. By positioning the center of gravity behind the tower, the gravitational force that could cause flipping instead becomes the mechanism that prevents it, eliminating the need for structural reinforcement

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 configuration provides reliable self-yawing and torque equalization, enhancing stability and reducing manufacturing costs by eliminating the need for active yaw systems and allowing for smaller tower diameters, while maximizing energy production.

Implementation Method 1

each energy generating unit having a centre of gravity, wherein at least two of the rotors are downwind rotors, the first energy generating units comprising the at least two first downwind rotors being arranged with their respective centres of gravity at a first distance behind the tower structure along a direction of the incoming wind

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentEP3443220B1A multirotor wind turbine

Publication Date: 2021.01.13 VESTAS WIND SYSTEMS AS

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AI summary

A multirotor wind turbine (1) comprising a tower structure (2) and at least one load carrying structure (3, 4), each load carrying structure (3, 4) being arranged for carrying two or more energy generating units (5, 7) comprising a rotor (6, 8). At least two of the rotors are upwind or downwind rotors (6), the energy generating units (5) comprising upwind or downwind rotors (6) being arranged with their centres of gravity at a first distance behind the tower structure (2) along a direction of the incoming wind, substantially at the same vertical level, and at opposite sides of the tower structure (2) at substantially the same second distance to the tower structure (2) along a direction substantially perpendicular to the direction of the incoming wind. The multirotor wind turbine (1) is self-yawing, even under turbulent wind conditions.