A method for generating an alternating electric current is provided. In the method, multiple partial currents are generated and superimposed into a total current. Each of the partial currents is generated using a modulation method. The modulation method uses a tolerance band method having tolerance limits that are changeable.

A method and system of subsynchronous oscillations and interactions damping integrated in in a rotor converter based on an adaptive state feedback controller with two spinning vectors, and a Kalman filter whose parameters are optimized by minimizing maximum sensitivity under a constraint of positive damping for a plurality of sensible scenarios is provided. The damping signal generated by the damping module is applied either to a power proportional integer controller or to a current proportional integer controller.

The invention relates to a control system for a wind turbine generator, WTG. The control system defines reactive limits for a reactive power reference for the WTG. The reactive limits are defined as a function of a physical parameter, e.g. the output voltage of the WTG. In case the reactive power reference exceeds the predefined limits, the reactive power reference is limited. By limiting the reactive power reference output voltages which exceed certain output voltage limits may be avoided and, thereby, a disconnection of the WTG from the grid may be avoided.

The invention relates to a control system for a wind turbine generator, WTG. The control system defines reactive limits for a reactive power reference for the WTG. The reactive limits are defined as a function of a physical parameter, e.g. the output voltage of the WTG. In case the reactive power reference exceeds the predefined limits, the reactive power reference is limited. By limiting the reactive power reference output voltages which exceed certain output voltage limits may be avoided and, thereby, a disconnection of the WTG from the grid may be avoided.

Described is a system that includes a polyphase generator and a polyphase bridge rectifier electrically coupled to an output of the polyphase generator. The polyphase bridge rectifier may output a positive rectified ripple signal and a negative rectified ripple signal, and the positive rectified ripple signal and the negative rectified ripple signal may be summed to produce a total ripple signal. Further, the system may include a generator regulation feedback control loop that regulates the output of the polyphase generator with a field control signal. In an embodiment, the field control signal is based on summing the total ripple signal and a reference voltage.

The present disclosure relates to a generator control device and a method to control the output power of at least one generator connected to an electric grid. It is an object of the invention to provide a fast solution to counteract electric grid frequency instabilities. Disclosed is a generator control device and method to control the output power of at least one turbogenerator driven by a turbine connected to an electric grid with a static frequency converter. The generator control device includes a frequency measuring device to measure the electric grid frequency f.sub.el, and the static frequency converter is configured to operate the turbogenerator in dependency of the measured electric grid frequency f.sub.el.

In a method of operating a generator connected to a power supply network, in particular a synchronous generator, during a network fault in the power supply network, in particular during an electric short-circuit, electric excitation of the generator is at least temporarily reduced based on the value of at least one operating parameter of the generator prior to the network fault and/or during the network fault.

In a method of operating a generator connected to a power supply network, in particular a synchronous generator, during a network fault in the power supply network, in particular during an electric short-circuit, electric excitation of the generator is at least temporarily reduced based on the value of at least one operating parameter of the generator prior to the network fault and/or during the network fault.

Provided is a method for controlling a wind power installation, the wind power installation having a generator for the generation of electric current, the generator having an air gap with a variable air gap thickness, the wind power installation being controlled in a part load range by means of a control regulation, the wind power installation being controlled in a manner which is dependent on the air gap thickness, the control regulation being selected or set in a manner which is dependent on the air gap width.

A system and method for protecting a genset from pole slip is disclosed. The system may comprise a generator, a prime mover and a controller. The generator includes a stator and a rotor. The prime mover is configured to drive rotation of the rotor. The controller may be configured to: determine mechanical status of the generator based on data associated with a translational displacement of the rotor; determine electrical status of the generator based on (a) a load angle or (b) the load angle and a rate of change of the load angle associated with rotation of the rotor in the stator; determine an operating condition of the generator based on fusion of the mechanical status and the electrical status; if the operating condition is a pole-slip-warning, activate an output member to display or emit a warning; and, if the operating condition is a pole-slip, activate a protective action.