Direct-Drive Wind Turbine Lightning Layout With Fewer SPDs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lightning protection systems for direct drive wind turbines require costly surge protection devices (SPDs) due to the classification of lightning protection zones (LPZs) within the turbine, leading to high installation costs.
Innovation Solution
A novel lightning protection arrangement that reclassifies certain LPZs as 'zone 2' by using protection conductors mounted on external surfaces of the electrical generator and hub, eliminating the need for additional SPDs at transitions between zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If protection conductors are mounted on external surfaces of the electrical generator and hub, then the classification of lightning protection zones is improved (reclassified as zone 2), but the device complexity increases due to additional conductor mounting requirements
Solution Approach 1:
The patent combines the protection conductor mounting with existing external surfaces of the electrical generator (rotor housing) and hub, merging the lightning protection function with structural surfaces already present in the wind turbine design. This approach achieves zone 2 classification without adding separate dedicated mounting structures.
Solution Approach 2:
The external surfaces of the electrical generator and hub serve dual purposes: their primary structural function and the additional function of serving as mounting surfaces for protection conductors. This multi-functionality reduces the need for dedicated conductor mounting hardware and simplifies the overall structure.
2Reliability
If surge protection devices are installed at all zone transitions, then the lightning protection reliability is improved, but the installation cost increases significantly
Solution Approach 1:
The patent changes the classification parameter of the lightning protection zones from zone 1 to zone 2 by implementing protection conductors on external surfaces. This parameter change in zone classification reduces the SPD requirements according to IEC 61400-24 standards, thereby reducing installation costs while maintaining adequate protection.
3Device complexity
If protection conductors are mounted on external surfaces, then the number of required surge protection devices is reduced, but the mounting surface requirements increase
Solution Approach 1:
The patent utilizes existing external surfaces of the electrical generator rotor housing and hub as mounting surfaces for protection conductors. These surfaces already exist as part of the wind turbine structure, so their area is not an additional requirement but rather an existing resource being put to dual use.
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
Reduces the requirement for surge protection devices, thereby lowering installation costs and simplifying the lightning protection system design.
Implementation Method 1
a plurality of protection conductors extending between the at least one blade and the tower
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A direct drive wind turbine (10) includes: a hub (13), at least one blade (17) fixed to the hub (13), a nacelle (14) on which the hub (13) is rotatably mounted for rotating about a rotational axis (Y), the nacelle (14) comprising an electrical generator (15) connected to the hub (13) in order to receive rotational energy from the hub (13), a tower (11) on which the nacelle (14) is mounted, a lightning protection arrangement (100) including a plurality of protection conductors (110) extending between the at least one blade (17) and the tower (11), the plurality of protection conductors (110) including at least a first protection conductor (111) mounted on an external surface of the electrical generator (15).