A method for operating a wind farm having a plurality of wind turbines, each of which is assigned a minimum power limit (CMPLj), wherein a power setpoint value (SPP) for a power which is to be fed in is specified for the wind farm, in dependence on which power setpoint value (SPP), individual wind turbines are activated or shut down, wherein the activation or shut-down of one or more wind turbines in the wind farm takes place in dependence on the respectively assigned minimum power limits (CMPLj), wherein each wind turbine of the wind farm is assigned a current value for its minimum power limit, and wherein the value takes into account variable operating conditions and/or ambient conditions of the respective wind turbine.

The invention relates to a method for controlling a wind turbine during start up, from a non-producing operation mode to a power producing operation mode when limit cycles occur during start-up. Limit cycles are detected when a number of cut-in transitions or a number of cut-out transitions are detected. A cut-in transition is when the wind turbine fails starting up despite having the wind speed or rotor speed normally required to enter a power producing operation mode. A cut-out transition is occurring when the wind turbine is falling out of power producing operation mode after having entered the power producing operation mode.

A bearing protection arrangement of a journal bearing arranged between a housing and a rotary component of a wind turbine. The bearing protection arrangement includes a wind speed monitor arranged to monitor wind speed in the vicinity of the wind turbine and to generate a wake-up signal when the wind speed exceeds a pre-defined minimum; a mode switch module of a backup battery arranged to provide restart power to an auxiliary of the wind turbine, which mode switch module is adapted to switch the backup battery from a normal-power mode into a low-power mode to conserve sufficient restart power after low wind-speed conditions, and to switch the backup battery from the low-power mode into a normal-power mode in response to the wake-up signal. A wind turbine and a method of protecting a journal bearing of a wind turbine during standstill.

A method for detecting an electrical fault in the stator of an electric machine is provided, wherein the stator includes multiple groups of windings, wherein the windings of each group are assigned to a respective phase of the electric machine, including the steps of: determining a respective current firstly between a subgroup of one of the groups of windings and a distinct further subgroup of the same group of windings and/or secondly between a subgroup of one of the groups of windings and a neutral point, and/or thirdly between a neutral point and either a further neutral point or to a common neutral point connected to at least the neutral point and the further neutral point, evaluating a fault condition, wherein the fulfilment of the fault condition depends on the respective determined current, and outputting a fault signal to personal and/or a device when the fault condition is fulfilled.

Systems and methods for controlling and monitoring agricultural equipment. The system includes a monitoring module that communicates with a remote user device to remotely turn a wind machine on or off.

The present disclosure relates to methods (300) to determine a duration of a period for warming up of a power converter (20) of a wind turbine (1). The method (300) comprises determining (301) a first indicator that is indicative of a time that the power converter (20) has been inactive. Further, the method (300) comprises determining (302) the period for warming up at least partially based on the first indicator. A power converter assembly is also disclosed.

Methods, systems, and devices for wind turbine control based on reinforcement learning are disclosed. The method comprises receiving data indicative of a current environmental state of the wind turbine, determining one or more controlling actions of the wind turbine based on the current environmental state of the wind turbine and a reinforcement learning algorithm, and applying the determined one or more controlling actions to the wind turbine.

A system and method are provided for controlling a wind farm during low wind speeds. Accordingly, the farm controller designates at least one of the plurality of wind turbines of the wind farm as a designated turbine. The designated turbine is operating in a full auxiliary mode when the speed of the wind acting on the wind farm is below a wind speed threshold. The remaining wind turbines are operated in a reduced auxiliary mode. The reduced auxiliary mode includes the disabling of at least one of pitching and yawing of the remaining wind turbines. When a power output for the designated wind turbine exceeds a power threshold, the farm controller directs at least one group of the remaining wind turbines to transition from the reduced auxiliary mode to the full auxiliary mode. During certain grid conditions, the transition between auxiliary modes may be delayed.

A method for operating a plurality of wind energy installations configured for supplying electric power to an electrical supply system, that each have an aerodynamic rotor with rotor blades and an electrical generator and also operating equipment, is disclosed. The wind energy installations are operated while they are not connected to the electrical supply system, where at least one of the wind energy installations produces electric power and inputs the electric power into a local DC voltage system that connects the wind energy installations if the at least one of the wind energy installations currently produces more power than needed for supplying its own operating equipment. Additionally or alternatively, the operating equipment is supplied totally or in part with power from the local DC voltage system if the at least one of the wind energy installations currently produces less power than needed for supplying its operating equipment.

A wind turbine assembly including a rotor system, a generator, a first converter, a second converter, and a controller system. The first converter includes a first bridge circuit having a plurality of switch members each having a controllable switch. The second converter includes a second bridge circuit having a plurality of switch members each having a controllable switch. The controller system is adapted to provide a drying operation for second converter including short circuiting the second converter with the controllable switches of the second bridge in circuit, and supplying power from the generator through the first converter to the short circuited second converter for drying the second converter.