A wind turbine blade comprising: an aerodynamic shell body with a suction side shell part and a pressure side shell part that extends in a longitudinal direction between a root and a tip and in a transverse direction between a leading edge and a trailing edge, and an electro-thermal system for mitigating ice formation on the wind turbine blade, the electro-thermal system comprising: a heating layer comprising electrically conductive fibres arranged to extend substantially in a longitudinal section of the aerodynamic shell body, wherein the electrically conductive fibres of the heating layer are configured for, upon receiving electrical power from a power cable, supplying resistive heating to an exterior side of the wind turbine blade so as to mitigate ice formation on the wind turbine blade; a metallic lightning protection layer arranged exteriorly to and overlapping the heating layer; and a down conductor being electrically connected to the metallic lightning protection layer so as to conduct a lightning strike current from the metallic lightning protection layer to the first end of the down conductor; wherein the heating layer and the metallic lightning protection layer are embedded in and co-infused with the aerodynamic shell body.

A wind turbine blade includes: an aerodynamic shell body with a suction side shell part and a pressure side shell part that extends in a longitudinal direction between a root and a tip and in a transverse direction between a leading edge and a trailing edge, and a de-icing system. The de-icing system includes: a number of heating layers each having electrically conductive fibres extending substantially in the longitudinal direction of the wind turbine blade along a longitudinal section of the aerodynamic shell body to provide resistive heating to the longitudinal section of the aerodynamic shell body; a number of metallic patches including a first metallic patch, the number of metallic patches being arranged to contact at least the number of heating layers; and a conductor cable that is electrically connected to the number of metallic patches and further is configured for electrically connecting to a power source.

A method of operating a heating system of a wind turbine connected to an electrical grid. The method includes receiving, via a heating circuit of the heating system, a voltage signal from the electrical grid. The method also includes processing the voltage signal using the heating circuit of the heating system. Processing the voltage signal using the heating circuit of the heating system includes superimposing a pulse width modulation (PWM) signal onto the voltage signal. Further, the method includes providing continuous temperature control to at least one heating element of the heating system via the PWM signal from the heating circuit. In addition, the method includes maintaining a temperature of the at least one heating element within a temperature range using the PWM signal during operation of the wind turbine to minimize temperature cycling of the at least one heating element.

A heating element for an outer surface of a wind turbine rotor blade, wherein the heating element has a length and a width. The heating element includes a carbon fiber layer having a plurality of slots subdividing the carbon fiber layer into consecutive band sections defining a current path between a first connecting portion and a second connecting portion. The first connecting portion is adapted to be connected to a first power supply line and the second connecting portion is adapted to be connected to a second power supply line. The current path has a length of at least twice the length of the heating element.

The present invention provides a method of repairing a metal mesh in a wind turbine blade part, damaged for instance by a lightning strike. The method comprises providing a wind turbine blade part; exposing a first metal mesh comprised in the wind turbine blade part; adhesively attaching a second metal mesh to the first metal mesh using an electrically conductive adhesive, such that the second metal mesh at least partially overlaps the first metal mesh; and covering the second metal mesh with cover material to finalise the repair. A corresponding wind turbine blade part is also provided.

A defrosting (or de-icing) system mountable on a surface of a mechanical part to be de-iced, comprising including a piezoelectric actuator, a fastening device to secure the actuator to the surface, and at least one control unit to activate the actuator to excite the part for defrosting. The actuator features a stacked structure of prestressed piezoelectric elements along its longitudinal axis. The fastening device secures the actuator parallel to the surface and includes fastening elements at each end, enabling excitation of the part in extension and bending modes.

A wind turbine includes a rotor blade, an electrical system embedded in the rotor blade and at least one switchable connection between the electrical system and ground. The at least one switchable connection is controllably switchable between an open state and a closed state so that, when the at least one switchable connection is in the closed state, the electrical system is grounded, and, when the at least one switchable connection is in the open state, the electrical system is not grounded.

A heating element for an outer surface of a wind turbine rotor blade, wherein the heating element has a length and a width. The heating element includes a carbon fiber layer having a plurality of slots subdividing the carbon fiber layer into consecutive band sections defining a current path between a first connecting portion and a second connecting portion. The first connecting portion is adapted to be connected to a first power supply line and the second connecting portion is adapted to be connected to a second power supply line. The current path has a length of at least twice the length of the heating element.

A method of operating a heating system of a wind turbine connected to an electrical grid. The method includes receiving, via a heating circuit of the heating system, a voltage signal from the electrical grid. The method also includes processing the voltage signal using the heating circuit of the heating system. Processing the voltage signal using the heating circuit of the heating system includes superimposing a pulse width modulation (PWM) signal onto the voltage signal. Further, the method includes providing continuous temperature control to at least one heating element of the heating system via the PWM signal from the heating circuit. In addition, the method includes maintaining a temperature of the at least one heating element within a temperature range using the PWM signal during operation of the wind turbine to minimize temperature cycling of the at least one heating element.

A wind turbine rotor blade including a wind turbine rotor blade shell structure including a fiber reinforced composite material; an electrical heating element arranged on an outer surface of the wind turbine rotor blade shell structure, the electrical heating element having an electrical heating conductor with an end section; an electrical supply line running along a longitudinal direction of the wind turbine rotor blade; and, a connector connecting the end section of the heating conductor electrically to the electrical supply line wherein the connector includes an outer thread screwed directly into the fiber reinforced composite material and into the electrical supply line.