The aim of this paper is to present a theoretical approach of the hypothesis of electrostatic charging of rotor blades during storms and its effects on the lightning protection and overvoltage protection systems; taking into consideration the dimensions of multi-megawatt wind turbines and a particular electrical topology.Overvoltage and overcurrent in form of surges may be the result of electromagnetic traveling waves caused by lightning strikes, especially if the earthing (grounding) system of the wind turbines (WTs) is galvanic connected between each other in order to ensure a common earth potential in the wind park (WP). These effects may impose additional requirements for the reliable operation of the low voltage and medium voltage protection against surges.