A method and apparatus for operating a converter system of a wind turbine for exchanging electrical power with an electrical supply grid at a grid connection point are provided. In the method and apparatus, the converter system is operated in a normal operating mode. An overload situation affecting the converter system is detected and operation of the converter system is changed to an overload operating mode when the overload situation is detected. An average switching frequency for generating an output current is reduced in the overload operating mode of the converter system in comparison with the normal operating mode, a higher load is permitted on the converter system, which may be in the form of an increased temperature or an increased output current, in the overload operating mode of the converter system for a predetermined maximum overload period.

Method for regulating a bank of alternators comprising at least two alternators that deliver their output in parallel to a load (C), said alternators each being provided with a regulator (12, 13) that is configured to deliver an output signal representative of the reactive power level of the corresponding alternator divided by its nominal reactive power, and a control law allowing the reactive power level of the alternator to be modified depending on an input signal, method wherein a weighted signal employed as the input signal of these regulators is generated from the output signals representative of the reactive power level of each of the alternators, i.e. the signals delivered by the corresponding regulators, so as to make each of the alternators converge to a predefined reactive power level (T.sub.rp).

A method of controlling a variable speed constant frequency (VSCF) power converter is provided. The method includes receiving a determination that a sensed AC current output has exceeded a predetermined limit. The AC current output is converted from a DC voltage and has a constant frequency. The DC voltage is converted from a variable frequency AC voltage. The variable frequency AC voltage is generated in response to a mechanical energy input having a varying parameter. The method further includes decreasing the DC voltage in response to a determination that the sensed AC current output has exceeded the predetermined limit.

A method of controlling a power generation apparatus and a pumped storage power generation apparatus including a motor directly connected to a rotor of a generator or generator motor, the method performing speed control by providing a guide vane opening degree command to the motor, the guide vane opening degree command being calculated by a rotational speed controller including a proportional control element, an integral control element, and a differential control element, in which a first upper limit limiting function is multiplied by a second upper limit limiting function, the first upper limit limiting function being included in an output runaway prevention circuit of an integral control function provided in the integral control element and being defined according to an output signal of a load limiter.

An aircraft propulsion system includes a gas turbine engine; a generator; a storage battery; a motor which drives a rotor, using at least one of the electric power which is output from the generator and the electric power which is output from the storage battery; a detection unit which detects the number of revolutions of the engine shaft; an engine control unit which controls at least a fuel flow rate of the gas turbine engine; and a generator control unit which controls the operation of the generator. When the number of revolutions satisfies a predetermined condition, at least the generator control unit executes a control for reducing a sudden change in the number of revolutions.

A method and apparatus for operating an overvoltage response for an electric machine includes opening a first switching element and a second switching element in response to an overvoltage condition. In the instance that the overvoltage condition persists, the method and apparatus can further open a third switchable element to cease the overvoltage condition.

The present disclosure provides a brushless direct current (BLDC) motor overload detection apparatus. The BLDC motor overload detection apparatus includes a measurer for measuring an electrical angle of the BLDC motor, a determiner for determining whether a difference between the electrical angle measured by the measurer and a mechanical angle of the BLDC motor, estimated through current supplied to the BLDC motor, is within a predetermined range, and a driving controller for control of driving of the BLDC motor according to whether the BLDC motor stalls, determined by the determiner.

The present disclosure relates to methods for determining a maximum power setpoint for a wind turbine comprising: determining an ambient temperature, determining a temperature of one or more wind turbine components and determining a current power output of the wind turbine. The methods further comprise determining the maximum power setpoint based at least partially on a thermodynamic model of the wind turbine components, the ambient temperature, the temperature of the components of the wind turbine and on the present power output of the wind turbine. The present disclosure further relates to methods for determining a setpoint reduction and to wind turbine control systems and wind turbines configured for such methods.

A main field connection to connect to a main field winding has a semi-cylindrical portion with an axially thicker outer surface, an axially thinner inner surface, with an aperture. An extending portion extends from the semi-cylindrical portion to a remote extending end. The remote extending end extends for a first axial distance. The axially thicker portion of the semi-cylindrical portion extends for a second axial distance. A ratio of the first axial distance to the second axial distance is between 0.65 and 1.4. A rotating assembly, a generator and a method are also disclosed.

Provided is a method for controlling a wind turbine for feeding electrical power into an electrical supply grid. The turbine comprises a tower, a nacelle, an aerodynamic rotor, a generator coupled to the aerodynamic rotor and intended for generating power from wind, a power unit for controlling the generator for controlling power output by the generator and/or for controlling a generator torque and a feed-in unit for feeding the power output by the generator or part thereof into the electrical supply grid. The method comprises controlling the turbine such that, in normal operation, a feed-in power is fed into the electrical supply grid in dependence on the wind and changing the feed-in power in dependence on a grid state and/or a grid demand of the electrical supply grid such that a specifiable mechanical, in particular momentary, loading limit of the turbine is maintained.