Post-Installation Magnetization for Wind Turbine PM Generators

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Solution Overview

Problem

The assembly of large-scale wind turbine generators with permanent magnet (PM) rotors is complicated by excessive magnetic forces between magnets and stator components, requiring specialized tools and posing safety concerns during installation and transportation.

Innovation Solution

Magnetizing the PM material after it is mounted on the rotor, allowing for the use of non-magnetic tools and minimizing safety precautions, with magnetization performed either in the wind turbine nacelle or on the tower, using a magnetization system with power converters to control the magnetization process, and integrating magnetization coils within the stator for efficient and safe magnetization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If permanent magnets are pre-magnetized before installation in large-scale wind turbine generators, then the magnetic field is ready for operation, but excessive magnetic forces require specialized non-magnetic tools and equipment for handling and installation

Engineering Contradiction:
Improvemagnetic field readinessVSAvoidspecialized tools and equipment
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-assembling the rotor with permanent magnets in a controlled environment (factory) where specialized handling equipment is available, then transporting the complete rotor assembly to the installation site. This resolves the contradiction by performing the magnetized state preparation in advance, eliminating the need for specialized tools during field installation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses non-magnetic holding means (such as non-magnetic fixtures or support structures) as intermediaries to handle and position the magnetized permanent magnets during assembly. These holding means act as mediators that allow manipulation of magnetized components without being affected by magnetic forces, thus enabling standard equipment to be used.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If permanent magnets are pre-magnetized before installation, then the generator is ready for operation, but personnel safety and transport require special precautions against excessive magnetic forces

Engineering Contradiction:
Improvegenerator operation readinessVSAvoidmagnetic forces affecting safety
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The rotor assembly with permanent magnets is pre-assembled and pre-magnetized in a controlled factory environment where safety precautions can be properly implemented. This preliminary action transfers the safety risks to the manufacturing phase rather than the installation phase, allowing standard safety protocols to be used during transportation and installation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements prior cushioning by using non-magnetic holding means and fixtures designed to withstand magnetic forces during assembly and transportation. These pre-prepared support structures cushion and contain the magnetic forces, protecting personnel and equipment from harmful magnetic effects during handling.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If permanent magnets are mounted in a magnetized state, then the magnetic field is established, but standard magnetic material equipment cannot be used for mounting and positioning

Engineering Contradiction:
Improvemagnetic field establishmentVSAvoidmounting and positioning process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs non-magnetic holding means as intermediaries between the magnetized permanent magnets and the mounting equipment. These holding means allow standard magnetic material equipment to be used indirectly, as the non-magnetic intermediaries transmit mechanical forces without being affected by magnetic fields, thus maintaining ease of manufacture while enabling magnetized component assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct magnetic interaction with mechanical interaction through non-magnetic holding means. Instead of relying on magnetic forces for positioning and mounting, the system uses mechanical fixtures and support structures that are immune to magnetic forces, allowing standard mechanical equipment to be used throughout the assembly process.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of manufacture

If permanent magnets are mounted without magnetization, then standard equipment can be used for installation, but the generator cannot operate until magnetization is performed

Engineering Contradiction:
Improveinstallation processVSAvoidgenerator operation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action by completing the magnetization process during the factory assembly phase rather than waiting until field installation. This ensures the generator is fully operational upon installation, eliminating the need for separate magnetization steps and allowing immediate commissioning.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent merges the assembly process and magnetization process into a single integrated operation. By combining these two steps that are typically separate, the system achieves both ease of manufacture (using standard equipment for assembly) and operational readiness (completing magnetization before installation) simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

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 method reduces the need for specialized tools, ensures safe handling and installation, and achieves optimal magnetization levels for improved performance by minimizing magnetic interference and allowing for uniform air gaps between the rotor and stator, thus enhancing the balance and induction efficiency of the generator.

Implementation Method 1

a magnetization system comprising magnetization coil means and at least one power supply

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2126352B2Method for establishing a wind turbine generator with one or more permanent magnet (PM) rotors, wind turbine nacelle and wind turbine
Publication Date: 2017.08.02 VESTAS WIND SYSTEMS AS
  • EP2126352B2 patent drawingFigure 1
  • EP2126352B2 patent drawingFigure 2~3b
  • EP2126352B2 patent drawingFigure 4a~4b

AI summary

The invention relates to a method for establishing a wind turbine generator with one or more Permanent Magnet (PM) rotors. The method comprises the steps of: manufacturing a generator prepared for taking one or more PM rotors, manufacturing one or more rotors comprising a plurality of holding means prepared for retaining PM material, mounting substantially non-magnetized PM material prepared for magnetization in said holding means before or after said one or more rotors are mounted in said generator, connecting a magnetization system for magnetizing said PM material in the generator, and magnetizing said PM material with said magnetization system. The invention also relates to a wind turbine nacelle, a wind turbine comprising said wind turbine nacelle and use of a wind turbine.