Wind Turbines offer preferred impact spots to
lightning, bearing high risks for humans being on or in the
facility during a thunderstorm. Depending on the position of
a person during the lightning strike to the facility, the risk
varies. In case maintenance work is done inside the hub,
people and electronics are protected against direct strikes
because of the Faraday cage structure of the hub. Major
phenomena that may be hazardous to humans inside the hub
are induced voltages due to magnetic fields, step and touch
voltages and shock waves. Control boxes that normally form
a closed metallic shielding against lightning current and
induced fields are usually open during maintenance, leaving
the electronics unprotected. To specify the magnetic fields
inside the hub, a method-of-moments simulation is used,
validated by respective near field measurements. The
measurements were performed using a 1.3 kA surge current
that has been injected into the hub. As during real lightning
strikes, currents up to 200 kA may occur, the numeric model
has to be extrapolated taking nonlinear material effects of
the hub’s cast iron into account.
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Wind Turbines offer preferred impact spots to
lightning, bearing high risks for humans being on or in the
facility during a thunderstorm. Depending on the position of
a person during the lightning strike to the facility, the risk
varies. In case maintenance work is done inside the hub,
people and electronics are protected against direct strikes
because of the Faraday cage structure of the hub. Major
phenomena that may be hazardous to humans inside the hub
are induced voltages due to magn...
»