Aspects of the present invention relate to a method for controlling an amount of reactive current provided from a wind turbine generator to a power grid during an abnormal power grid event, said wind turbine generator comprising a doubly-fed induction generator having a rotor and a stator, and a power converter coupling the rotor to the power grid, the power converter comprising a grid-side inverter, wherein the method comprises the step of balancing the reactive current provided to the power grid between a reactive stator current and a reactive grid-side inverter current, wherein the reactive grid-side inverter current is controlled in accordance with a reactive current capacity of a grid breaker receiving the reactive current provided by the grid-side inverter. Aspects of the present invention also relate to a wind turbine generator being capable of performing the method.

A system and method for protecting an idling wind turbine power system from damage during loss of grid power. The wind turbine power system has a plurality of rotor blades. The method includes monitoring an incoming wind direction at the wind turbine power system. When the incoming wind direction is changing at a predetermined attack angle, the method also includes rotating at least one of the rotor blades of the wind turbine power system to a pitch angle that is offset from a feather position by a predetermined number of degrees to reduce and/or eliminate flutter phenomenon from occurring.

A method to control a wind power installation is provided. The wind power installation includes a generator and a converter. The generator is configured to convert wind power into electrical power and to provide the electrical power from the generator to the converter. The converter is configured to adapt and to provide the electrical power to an electrical grid. The converter is operable to comply with pre-determined grid code requirements during a grid fault. An amount of electrical power, which is present in the wind power installation during the grid fault, is fed into the generator. The generator is operable to convert the respective amount of electrical power into a generator loss.

The present invention relates to operation of a wind turbine using a power storage unit, such as a rechargeable battery, to power a group of power consuming units during grid loss. The wind turbine comprises a number of power consuming units being grouped into at least a first group and a second group, a first electrical converter for connecting the generator to the electrical grid, and a second electrical converter for connecting the electrical generator to the power storage unit. Upon detecting an occurrence of the grid loss, the generator is operated to ensure sufficient power of the power storage unit to operate the first group of power consuming units.

Installation for converting hydraulic energy into electrical energy, provided with a fixed speed hydraulic machine comprising a pump-turbine (2) linked to a generator (20) by a shaft.

The installation further comprises: an electrical torque actuator (34) to establish a circuit with the generator (20), electrical torque actuator connection means (35) for connecting the generator (20) the electrical torque actuator, and command means (29) for detecting a disconnection of the generator (20) from the grid, and for commanding the electrical torque actuator connection means (35) to connect the generator (20) to the electrical torque actuator (34).

Provided are a method and a system for controlling wind turbine shutdown. The method includes: obtaining, according to a preset sampling period, a grid voltage for a wind turbine, and sending the obtained grid voltage to an converter controller; determining, by the converter controller and based on the grid voltage, an operating condition of a power grid is power outage of power grid; sending, in a case that the power outage of power grid is determined, a signal indicating power outage of power grid to a main controller of a main control system of the wind turbine; and controlling, by the main controller in a case that the signal indicating power outage of power grid is received, a pitch system to perform a variable-rate feathering.

The present invention relates to a wind turbine comprising an internal power supply grid for distributing power to a number of power consuming units of the wind turbine, the wind turbine further comprising a power backup system connected to the internal power supply grid for supplying power to said internal power supply grid during a grid fault, wherein the power backup system comprises a power storage module providing a total backup voltage that falls within a nominal voltage range of the internal power supply grid of the wind turbine.

The present disclosure provides a primary frequency modulation method for a wind turbine, which may include: detecting a current frequency of a power grid; determining an instruction value of a power change amount for a primary frequency modulation by a first determining process when the current frequency of the power grid is less than a standard frequency of the power grid, wherein the first determining process may include: determining a reference value of the power change amount for the primary frequency modulation based on the current frequency; and when it is determined that currently there is an active power headroom for the wind turbine, comparing the reference value with a current active power headroom value of the wind turbine and determining the instruction value of the power change amount for the primary frequency modulation; and performing the primary frequency modulation based on the instruction value of the power change amount.

A method for providing a requested real power including receiving the requested real power at a transmission feed-in point; using a real power band with an upper band limit and a lower band limit, each of which is disposed with an offset from the requested real power. The real power band furthermore comprises at least one control threshold value between the upper band limit and the lower band limit. The method includes controlling at least one regenerative energy generator depending on the at least one control threshold value, in particular in order to provide the requested real power as transmission power at the transmission feed-in point.

A method for controlling wind farm operation during a weak grid condition includes determining when a threshold number of the plurality of wind turbines have tripped based on the received one or more inputs. Furthermore, the method includes determining a sampled power output of the wind farm based on received sensor data after it is determined that the threshold number of the plurality of wind turbines have tripped. Additionally, the method includes controlling the operation of the one or more wind turbines of the plurality of wind turbines that have not tripped after it is determined that the threshold number of the plurality of wind turbines have tripped such that the power output of the one or more wind turbines of the plurality of wind turbines that have not tripped is less than or equal to the sampled power output.