Wind Turbine Rotor Blade Potential Equalization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wind turbine rotor blades face difficulties in reliable potential equalization between pressure-side and suction-side lightning protection conductors, particularly at outer radius positions, where the profile thickness is small and interior access is limited, leading to increased risk of flashovers.

Innovation Solution

An equipotential bonding element is arranged on the outer side of the rotor blade, leading around the profile end edge, allowing for easy installation and connection after assembly, and serving as an additional lightning protection receptor to enhance current-carrying capacity and reduce flashover risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If equipotential bonding elements are arranged inside the rotor blade to connect lightning protection conductors, then potential equalization is achieved, but installation becomes difficult at outer radius positions where profile thickness is small and interior access is limited

Engineering Contradiction:

Improvepotential equalizationVSAvoidinstallation accessibility

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent inverts the conventional arrangement by placing the equipotential bonding element on the outer side of the rotor blade instead of inside. This allows the bonding element to be installed and accessed from the exterior, eliminating the accessibility problems at outer radius positions while still achieving effective potential equalization between the pressure-side and suction-side lightning protection conductors.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The bonding element is configured to extend around the profile end edge in a circumferential direction, utilizing the outer surface dimension of the rotor blade. This dimensional approach allows the bonding element to bridge between lightning protection conductors on opposite sides of the blade without requiring interior access, solving the installation accessibility issue.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If multiple electrically conductive elements are arranged in parallel within the rotor blade, then lightning protection coverage is improved, but large potential differences occur through electromagnetic induction leading to flashovers

Engineering Contradiction:

Improvelightning protection coverageVSAvoidflashover risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies equipotential bonding by connecting the pressure-side and suction-side lightning protection conductors through the bonding element arranged on the outer side of the rotor blade. This equalizes the potential between the parallel conductive elements, preventing large potential differences and eliminating the flashover risk while maintaining comprehensive lightning protection coverage.

Inventive Principle:

Principle #12Equipotentiality

3Ease of operation

If the equipotential bonding element is arranged on the outer side of the rotor blade, then installation ease and additional lightning protection are achieved, but aerodynamic impairment may occur

Engineering Contradiction:

Improveinstallation easeVSAvoidaerodynamic impairment

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The bonding element is strategically positioned and configured to extend around the profile end edge where it is least likely to interfere with the main aerodynamic flow over the blade surface. The local arrangement minimizes aerodynamic impairment while still achieving the equipotential bonding function and providing additional lightning protection capability.

Inventive Principle:

Principle #3Local quality

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 facilitates improved lightning protection by ensuring effective potential equalization and current discharge, reducing the risk of flashovers and damage, while minimizing aerodynamic impairment.

Implementation Method 1

an equipotential bonding element that electrically connects the two lightning protection conductors

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

Due to the high lightning currents, large potential differences occur between the different electrically conductive elements through electromagnetic induction

Methodology Applied

Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 3

The current from a lightning strike to the receiver is then conducted via a lightning conductor to the blade root and from there through the nacelle and tower of the wind turbine into the ground

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Data Source

PatentEP2930358B1Wind turbine rotor blade with a potential equalisation element

Publication Date: 2018.08.29 NORDEX ENERGY

Figure 1
Figure 2
Figure 3~4

AI summary

Wind turbine rotor blade with a blade root, a pressure side, a suction side, a profile end edge, a pressure-side lightning protection conductor and a suction-side lightning protection conductor, wherein the two lightning protection conductors are designed to conduct a lightning current towards the blade root, and an equipotential bonding element that electrically connects the two lightning protection conductors, characterized in that the equipotential bonding element is arranged on an outside of the wind turbine rotor blade and leads around the profile end edge.