Wind turbine having low-harmonic converter system, and method for operation
AssigneeSenvion SE
InventorHeinz-Hermann LETAS
Life of this patent
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Abstract
A converter controller is provided, by which the current valves are controlled by means of a switching frequency. It is provided to alter the switching frequency in a step-wise manner between a first and at least one second integral multiple of the grid frequency. According to the invention, this is effected in that the switching frequency is switched over cyclically, and a frequency spacing between the switching frequencies is at least double the grid frequency, specifically in such a manner that none of the switching frequencies is an integral multiple of another of the switching frequencies. In this way, harmonics can be selectively reduced, no intermediate frequencies being produced, owing to the integrality in relation to the grid frequency.
Claims21
A method for operating a wind turbine having a generator, which is driven by a wind rotor and which acts in combination with a converter to generate electrical power that is delivered at grid frequency via a connection line, the converter comprising at least one grid-side inverter having current valves, and a converter controller being provided for controlling the converter, the current valves being controlled by a control signal using a switching frequency, the method comprising:
- altering the switching frequency in a step-wise manner between a first integral multiple of the grid frequency and at least one second integral multiple of the grid frequency, the switching frequency being switched over cyclically, and a frequency spacing between switching frequencies being at least double the grid frequency, and none of the switching frequencies being an integral multiple of another of the switching frequencies.
A wind turbine comprising:
- a converter comprising at least one grid-side inverter having current valves;
- a generator, which is driven by a wind rotor and which acts in combination with the converter to generate electrical power that is delivered at grid frequency via a connection line;
- and
- a converter controller that is configured for controlling the current valves of the converter by a control signal using a switching frequency, wherein the converter controller is configured for cyclically switching over the switching frequency in a step-wise manner between a first integral multiple of the grid frequency and at least one second integral multiple of the grid frequency, wherein a frequency spacing between the switching frequencies is at least double the grid frequency, and none of the switching frequencies is an integral multiple of another of the switching frequencies.
Dependencies are inferred from the claim text.