Wind Turbine Electrical Protection System for Static and Lightning Discharge

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Solution Overview

Problem

Current lightning protection systems for wind turbines face high wear due to sliding contacts and fail to effectively discharge static electricity, leading to electromagnetic noise in neighboring equipment.

Innovation Solution

An electrical protection system with a first discharging unit for continuous static electricity discharge to the ground and a second discharging unit with spark gaps to manage lightning current, using conductive and insulating components connected in specific configurations to ensure efficient grounding during lightning events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sliding contact is used to transfer lightning current and static electricity, then the current can be discharged to ground, but the sliding contact experiences high wear and requires critical maintenance

Engineering Contradiction:
Improvecurrent discharge reliabilityVSAvoidsliding contact service life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent replaces the mechanical sliding contact system with a brushless alternator system that uses electromagnetic induction. The excitation current is transferred through a stationary slip ring and brush assembly, while the alternating current generated in the rotating field winding is transmitted to the stator terminals without mechanical sliding contacts, thereby eliminating wear and maintenance issues associated with sliding contacts

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

2Adaptability or versatility

If a common circuit is used to discharge both lightning strike current and electrostatic discharge current, then both currents can be transferred to ground, but it is difficult to guarantee sufficient contact pressure along the whole distance of the drip rail

Engineering Contradiction:
Improvemulti-current discharge capabilityVSAvoidcontact reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the current discharge paths by using separate windings in the alternator: the field winding handles excitation current transfer through the stationary slip ring, while the armature winding handles the generated alternating current through stationary stator terminals. This segmentation ensures reliable electrical contact without requiring continuous sliding contact along the entire drip rail

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If conventional lightning protection components are used to direct lightning discharge to ground, then lightning strike protection is provided, but static electricity accumulated at the blades cannot be discharged

Engineering Contradiction:
Improvelightning strike protectionVSAvoidelectromagnetic noise from static electricity
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent creates a universal electrical system that handles multiple functions: the alternator simultaneously manages excitation current transfer, generated power output, and provides a continuous electrical path from rotating components to ground. This multi-functional system enables both lightning strike protection and static electricity discharge through the same electrical infrastructure, preventing electromagnetic noise

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 system effectively discharges static electricity and lightning current without wear issues, reducing electromagnetic noise and protecting wind turbines from lightning strikes.

Implementation Method 1

a first discharging unit configured for being in contact with some metallic part of the blade and for continuously discharging to the ground, through the hub metallic structure, the static electricity accumulated at the blades

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a first spark gap with a first gap breakdown voltage and a second spark gap with a second gap breakdown voltage

Methodology Applied
Scientific EffectElectrical breakdown: Electric Spark

Data Source

PatentEP3775544B1Electrical protection system for wind turbines
Publication Date: 2023.02.15 GAMESA INNOVATION & TECH SL
  • EP3775544B1 patent drawingFigure 1
  • EP3775544B1 patent drawingFigure 2
  • EP3775544B1 patent drawingFigure 3

AI summary

Electrical protection system allowing transferring to the ground static electricity accumulated onto the blades of a wind generator, and the lightning current when a lightning strikes onto at least one of the blades or at the rotor, comprising a first discharging unit configured for continuously discharging to the ground the static electricity accumulated onto the blades, and a second discharging unit configured for discharging to the ground the lightning current when a lightning strikes in at least one of the blades or at the rotor.