Lightning protection of a sectioned wind turbine blade

A wind turbine blade extending along a longitudinal axis from a root through a first airfoil region and a second airfoil region to a tip, the wind turbine blade comprising a first blade section extending along the longitudinal axis to a first end and a second blade section extending along the longitudinal axis from a second end towards the tip, the first blade section comprising the first airfoil region, the second blade section comprising the second airfoil region, the wind turbine blade comprising a spar beam structurally connecting the first blade section and the second blade section, the spar beam longitudinally extending along a spar beam axis from a first beam end at a first beam axis position to a second beam end at a second beam axis position and being positioned such that the first beam axis position is located in the first airfoil region and the second beam axis position is located in the second airfoil region and a third beam axis position, between the first beam axis position and the second beam axis position, is aligned with the second end of the second blade section,

• wherein the spar beam comprises a conductive beam sheath circumscribing at least a beam sheath angular distance of the spar beam about the spar beam axis and longitudinally extending along the spar beam axis from a fourth beam axis position to a fifth beam axis position, and
• wherein the fourth beam axis position and the third beam axis position are separated by a first distance, the first distance being more than 10 mm.

A wind turbine blade extending along a longitudinal axis from a root through a first airfoil region and a second airfoil region to a tip, the wind turbine blade comprising a first blade section extending along the longitudinal axis to a first end and a second blade section extending along the longitudinal axis from a second end towards the tip, the first blade section comprising the first airfoil region, the second blade section comprising the second airfoil region, the wind turbine blade comprising a spar beam structurally connecting the first blade section and the second blade section, the spar beam longitudinally extending along a spar beam axis from a first beam end at a first beam axis position to a second beam end at a second beam axis position and being positioned such that the first beam axis position is located in the first airfoil region and the second beam axis position is located in the second airfoil region and a third beam axis position, between the first beam axis position and the second beam axis position, is aligned with the second end of the second blade section,

• wherein the spar beam comprises a conductive beam sheath circumscribing at least a beam sheath angular distance of the spar beam about the spar beam axis and longitudinally extending along the spar beam axis from a fourth beam axis position to a fifth beam axis position,
• wherein the first blade section comprises a first down conductor configured for conducting lightning current to ground,
• wherein the first down conductor is electrically connected to the first conductive shell sheath and/or the second conductive shell sheath,
• wherein the second blade section comprises a second down conductor being connected to the first down conductor of the first blade section, and
• wherein the second down conductor is electrically connected to the conductive beam sheath at a sixth beam axis position, wherein the sixth beam axis position is between the fourth beam axis position and the fifth beam axis position, and wherein the sixth beam axis position and the fifth beam axis position is separated by a second distance, the second distance being less than 100 nm.