A wind turbine monitoring device for monitoring a wind turbine including a lightning sensor for detecting a lightning strike on a wind turbine blade includes a lightning parameter acquisition part configured to acquire at least one lightning parameter based on an output of the lightning sensor, a lightning level determination part configured to determine a level of the lightning strike based on the at least one lightning parameter acquired by the lightning parameter acquisition part; and an inspection control part configured to judge whether it is necessary to automatically inspect the wind turbine blade by at least one inspection unit for inspecting the wind turbine blade, according the level of the lightning strike determined by the lightning level determination part.

A lightning protection system for a wind turbine blade, includes: a receptor disposed in a tip portion of the wind turbine blade; a leading edge protection portion made of a metal and electrically connected to the receptor and disposed so as to cover a leading edge of the wind turbine blade; a down conductor connected to the receptor; at least one connecting conductor for electrically connecting the leading edge protection portion and the down conductor at a position between the receptor and a blade root in a blade spanwise direction of the wind turbine blade; and a first current sensor for measuring a current flowing through a blade tip-side portion which is a portion, of the down conductor, between a blade tip and a connection point with the at least one connecting conductor in the blade spanwise direction.

A method of operating an electrical heating element of a wind turbine rotor blade, the method includes: applying a voltage to the heating element, measuring a current flowing through the heating element, measuring the voltage applied to the heating element, calculating a reference current by applying a normalization factor to the measured current, wherein the normalization factor corresponds to the ratio of a nominal voltage to the measured voltage, triggering an action when the reference current is outside a first predetermined reference current range.

A method of estimating a second power curve of a wind turbine regarding a second operational configuration includes: receiving power output data pertaining to a first operational configuration, in particular reference operational configuration; receiving power data relating to power output pertaining to the second operational configuration; deriving the second power curve using the power output data pertaining to the first operational configuration, the power output data pertaining to the second operational configuration and a first power curve of the first operational configuration.

It is described a method of determining at least one high-level limitation of a system including a doubly fed induction machine, the method comprising: receiving at least one system operation condition parameter related to the actual operation condition; calculating the high-level limitation based on at least one low-level limitation at least one component of the system and the system operation condition parameter, wherein the method is particular performed, while the system is in operation.

A method is for estimating health status of a pitch energy storage unit of a wind turbine. The method includes: providing an equivalent circuit model, ECM, of the storage unit, the ECM including an equivalent series resistor and an electrical energy storage element connected between two terminals; repeatedly sampling a voltage and a corresponding current at the two terminals; determining a voltage change and a current change for a plurality of voltage samples and corresponding current samples; performing an optimization procedure based at least on the ECM, the plurality of the voltage samples, the determined voltage changes, and the determined current changes to obtain an updated resistance of the equivalent series resistor and an updated model parameter of the storage element; and estimating a status of health parameter for the storage unit by comparing at least one of the updated resistance and the updated parameter with a threshold value.

A method is for operating an electrical heating element of a wind turbine rotor blade. The method includes: applying a voltage to the heating element, measuring a current flowing through the heating element, measuring the voltage applied to the heating element, calculating a reference current by applying a normalization factor to the measured current, wherein the normalization factor corresponds to the ratio of a nominal voltage to the measured voltage, triggering an action when the reference current is outside a first predetermined reference current range.

A method of controlling electrical power transported on one or more power cables of a wind park is provided. Each of the one or more power cables is configured to transport electrical power generated by one or more wind turbines comprised in the wind park. The method includes for at least one power cable of the one or more power cables monitoring one or more stress parameters indicative of stress acting on the power cable to generate a monitored stress parameter, determining, based on at least the monitored stress parameter, whether a reduction of the stress on the power cable is required, and, when the reduction is required, reducing the electrical power transported on the power cable to reduce the stress acting on the power cable.

A wind turbine monitoring device for monitoring a wind turbine including a lightning sensor for detecting a lightning strike on a wind turbine blade includes a lightning parameter acquisition part configured to acquire at least one lightning parameter based on an output of the lightning sensor, a lightning level determination part configured to determine a level of the lightning strike based on the at least one lightning parameter acquired by the lightning parameter acquisition part; and an inspection control part configured to judge whether it is necessary to automatically inspect the wind turbine blade by at least one inspection unit for inspecting the wind turbine blade, according the level of the lightning strike determined by the lightning level determination part.

Provided are an off-grid wind-hydrogen energy supply system for polar regions and a control method thereof, and relate to the field of new energy supply. In the system, wind energy is converted by a wind power generation system into electric energy, and a cryogenic battery energy storage system is charged. Chemical energy of hydrogen and oxygen is converted by a hydrogen fuel cell system into electric energy, and the cryogenic battery energy storage system is charged. Energy is stored by the cryogenic battery energy storage system, a wind power fluctuation is mitigated, and a load is smoothened. Operation parameters of the wind power generation system, the cryogenic battery energy storage system, and the hydrogen fuel cell system are obtained by an intelligent monitoring system.