For each of actuators, the partial load ratio is output. An output device for a drive device of a wind turbine includes an obtaining unit for obtaining information relating to a load applied to each of a plurality of actuators, where the actuators are included in the drive device of the wind turbine and configured to cooperate with each other, a processing unit for, based on the information obtained by the obtaining unit, calculating a partial load ratio, where the partial load ratio represents a ratio of a load on each of the actuators to a total load and the total load is a sum of the loads on the respective actuators, and an output unit for outputting the partial load ratio.

A generator-gearbox arrangement for a wind turbine includes a generator having a stator and a rotor interacting with one another, a functional component arranged on an end side of the generator and including an extension which points toward the rotor, and a magnetic rail brake arrangement including component parts fastened to the extension. The magnetic rail brake arrangement is designed to apply a braking action which is based on an operating principle of electromagnetic attraction between the magnetic rail brake arrangement and at least one of the rotor and the functional component.

A system and method are provided for applying a pitch motor braking torque to a rotor blade. Accordingly, of the pitch control system from a 1.sup.st operational mode to an emergency operational mode is initiated. The pitch motor of the pitch control system having an absence of supply current during the transition. A short-circuit is established across the Armature of the pitch motor so as to establish a current flow. The current is generated by the pitch motor in response to rotation of the rotor blade about the pitch axis when the pitch motor has the absence of supply current. In response to the current flow being generated, generating a braking torque in a single direction with the pitch motor so as to allow the rotor blade to move freely to a lesser loaded orientation relative to an original orientation to protect the wind turbine from damage.

A system and method are provided for applying a pitch motor braking torque to a rotor blade. Accordingly, of the pitch control system from a 1.sup.st operational mode to an emergency operational mode is initiated. The pitch motor of the pitch control system having an absence of supply current during the transition. A short-circuit is established across the Armature of the pitch motor so as to establish a current flow. The current is generated by the pitch motor in response to rotation of the rotor blade about the pitch axis when the pitch motor has the absence of supply current. In response to the current flow being generated, generating a braking torque in a single direction with the pitch motor so as to allow the rotor blade to move freely to a lesser loaded orientation relative to an original orientation to protect the wind turbine from damage.

A rotary machine includes a stator and a rotor that rotates relative to the stator in response to flow of a fluid by or through the rotor. The rotary machine also includes a control circuit configured to determine one or more operational characteristics of the electric machine. The one or more operational characteristics are indicative of a flow of the fluid or a load placed on the rotary machine, the control circuit configured to apply control signals to control one or more switches of the rotary machine to induce a magnetic field in the rotary machine that resists a force imparted on a rotor of the rotary machine from the flow of the fluid. The control signals control the one or more switches of the rotary machine to control a speed at which the rotor rotates.

A vibration absorber which, in the broadest sense, is based on a pendulum device for dampening undesirable vibrations which occur in a very slender structure, such as a wind turbine. The undesirable vibrations are caused by an acting force, in particular wind force. The invention thereby relates to vibration absorbers in which the pendulum mass can be temporarily stopped or braked, either entirely or partially, by an electromagnetic brake. The power supply or the current regulation of the electromagnetic brake correspondingly controls the braking function of the electromagnetic brake.

A method is provided for braking a rotor of a wind turbine. The rotor comprises rotor blades. The wind turbine comprises a pitch adjustment system for adjusting a pitch of the rotor blades. The method comprises detecting a system failure of the pitch adjustment system, estimating a current wind speed, estimating an available brake torque and estimating a required brake torque, based on the estimated current wind speed. The method further comprises determining a suitable point in time for activating a rotor brake based on the estimated available brake torque and the estimated required brake torque. The rotor brake is then activated at the determined suitable point in time.

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.

A power converter assembly for an electrical power system connected to a power grid includes a rotor-side converter configured for coupling to a generator rotor of a generator of the electrical power system, a line-side converter electrically coupled to rotor-side converter via a DC link, and a dynamic brake assembly electrically coupled to the DC link. The line-side converter is configured for coupling to the power grid. The dynamic brake assembly includes a plurality of switching devices connected in parallel and a plurality of inductors electrically coupled between the plurality of switching devices.

A power converter assembly for an electrical power system connected to a power grid includes a rotor-side converter configured for coupling to a generator rotor of a generator of the electrical power system, a line-side converter electrically coupled to rotor-side converter via a DC link, and a dynamic brake assembly electrically coupled to the DC link. The line-side converter is configured for coupling to the power grid. The dynamic brake assembly includes a plurality of switching devices connected in parallel and a plurality of inductors electrically coupled between the plurality of switching devices.