Abstract: A wind turbine blade comprising a lightning protection system, which is at least partly disposed in an inboard portion of the blade. The lightning protection system comprises a down conductor cable having root and tip portions having insulation with different electrical breakdown voltages. The lightning protection system may comprise a down conductor cable portion and a supporting component to hold the cable portion in free space in a position near or on a camber line of the blade aerofoil section, so that the cable portion is spaced apart from at least one electrically conductive structural component; and/or a plurality of inboard down conductor cables and a diverging electrical junction.

Abstract: A wind turbine blade comprising a lightning protection system, which is at least partly disposed in an inboard portion of the blade. The lightning protection system comprises a down conductor cable portion and a supporting component to hold the cable portion in free space in a position near or on a camber line of the blade aerofoil section, so that the cable portion is spaced apart from at least one electrically conductive structural component. The lightning protection system may comprise a plurality of inboard down conductor cables and a diverging electrical junction; and/or a down conductor cable having root and tip portions having insulation with different electrical breakdown voltages.

Abstract: A wind turbine blade comprising a lightning protection system, which is at least partly disposed in an inboard portion of the blade. The lightning protection system comprises a down conductor cable having root and tip portions having insulation with different electrical breakdown voltages. The lightning protection system may comprise a down conductor cable portion and a supporting component to hold the cable portion in free space in a position near or on a camber line of the blade aerofoil section, so that the cable portion is spaced apart from at least one electrically conductive structural component; and/or a plurality of inboard down conductor cables and a diverging electrical junction.

Abstract: A wind turbine blade comprising a lightning protection system, which is at least partly disposed in an inboard portion of the blade. The lightning protection system comprises a plurality of inboard down conductor cables and a diverging electrical junction. The lightning protection system may comprise a down conductor cable having root and tip portions having insulation with different electrical breakdown voltages and/or a down conductor cable portion and a supporting component to hold the cable portion in free space in a position near or on a camber line of the blade aerofoil section, so that the cable portion is spaced apart from at least one electrically conductive structural component.

Abstract: A wind turbine rotor blade has a spar cap including conductive material, and a lightning conductor extending over the spar cap. There is a non-conductive layer between the lightning conductor and the spar cap. An equipotential bonding element electrically bonds the lightning conductor to the spar cap. The non-conductive layer is discontinuous to define a gap, and the equipotential bonding element extends through the gap.

Abstract: A wind turbine rotor blade has a spar cap including conductive material, and a lightning conductor extending over the spar cap. There is a non-conductive layer between the lightning conductor and the spar cap. An equipotential bonding element electrically bonds the lightning conductor to the spar cap. The non-conductive layer is discontinuous to define a gap, and the equipotential bonding element extends through the gap.

Abstract: A wind turbine rotor blade spar cap includes a stack of layers of conductive material. An intermediate layer is bonded between adjacent layers of the conductive material. The intermediate layer includes a portion of conductive material which is electrically coupled to the adjacent layers of conductive material so as to equipotentially bond the adjacent layers of the conductive material via the intermediate layer.