Lightning protection system for a wind turbine rotor blade and a method for manufacturing such a blade

A method for manufacturing a wind turbine rotor blade where said method comprises:

• providing at least two blade shells enclosing a cavity,
• placing a lightning receptor base with a connection to a lightning down conductor on one blade shell,
• establishing contact between the lightning receptor base and at least one lightning receptor at the surface of the blade at a distance from a distal end of the blade tip and between said at least two blade shells, and
• filling at least a portion of the cavity with a dielectric material having a dielectric strength that is larger than air, thereby changing at least one electric property of the rotor blade at the lightning receptor base, as compared to the electric properties of ambient air, where at least one internal barrier is positioned in the distal end of at least one of the blade shells at an internal distance from the distal end of the blade tip.

A method for manufacturing a wind turbine rotor blade, comprising:

• providing at least two blade shells,
• placing a lightning receptor base with a connection to a lightning down conductor on one blade shell,
• establishing contact between at least one lightning receptor at the surface of the blade in an external distance from a distal end of the blade tip and the lightning receptor base and between said at least two blade shells, and
• changing at least one electric property of the rotor blade at the lightning receptor base, as compared to the electric properties of ambient air by increasing the electric field supported between the lightning receptor base and the inner surface of the rotor blade, where the lightning receptor base and the lightning down conductor are embedded and connected in a prefabricated implant, where said prefabricated implant is adapted to an inner surface of the blade by elevations of the implant.