Patent application number | Description | Published |
20120169059 | METHOD AND DEVICE FOR MONITORING THE STATE OF A NETWORK - The present invention concerns a method of detecting electric variables of a three-phase AC network having a first, a second and a third phase, including the steps of measuring a respective voltage value of the first, second and third phases in relation to a neutral conductor at a first moment in time, transforming the three voltage values of the first moment in time into polar co-ordinates with a voltage amplitude and a phase angle, repeating measurement and transformation for at least one further moment in time, and determining the currently prevailing frequency, voltage amplitude and/or phase angle of at least one of the phases from the voltage values transformed into polar co-ordinates. | 07-05-2012 |
20140184174 | METHOD FOR CONTROLLING A WIND TURBINE - The present invention concerns a method of controlling a wind power installation having a generator with a stator, a pole wheel with at least two rotor poles with a respective pole winding for producing a magnetic field guided in the respective rotor pole, and an air gap between the stator and the pole wheel, including the steps— controlling a respective exciter current through each pole winding,— varying at least one of the exciter currents relative to at least one further one of the exciter currents, and/or— varying at least one of the exciter currents in dependence on the position of the pole wheel in relation to the stator. | 07-03-2014 |
20140254216 | METHOD AND APPARATUS FOR FEEDING ELECTRICAL CURRENT INTO AN ELECTRICAL POWER SUPPLY SYSTEM - The invention relates to a method for feeding electrical current into an electrical, three-phase power supply system having a first phase, a second phase and a third phase with a first voltage, a second voltage and a third voltage at a power supply system frequency, comprising the steps of: measuring the first, second and third voltages, transforming the first, second and third voltages into a positive phase-sequence voltage system and a negative phase-sequence voltage system according to the method of symmetrical components, calculating a first desired current, a second desired current and a third desired current for feeding into the first, second and third phases of the power supply system, wherein the first, second and third desired currents are calculated on the basis of at least one value of the positive phase-sequence voltage system and/or the negative phase-sequence voltage system. | 09-11-2014 |