Method and Apparatus for Obtaining Electricity from Offshore Wind Turbines

摘要

According to one aspect of the teachings herein, various feeder connection arrangements and architectures are disclosed, for collecting electricity from wind turbines in an offshore collection grid that operates at a fixed low frequency, e.g., at one third of the targeted utility grid frequency. Embodiments herein detail various feeder arrangements, such as the use of parallel feeder connections and cluster-based feeder arrangements where a centralized substation includes a common step-up transformer for outputting electricity at a stepped-up voltage, for low-frequency transmission to onshore equipment. Further aspects relate to advantageous generation arrangements, e.g., tower-based arrangements, for converting wind power into electrical power using, for example, medium-speed or high-speed gearboxes driving generators having a rated electrical frequency for full-power output in a range from about 50 Hz to about 150 Hz, with subsequent conversion to the fixed low frequency for off-shore collection.

主权项

1. A system configured for obtaining electricity in an offshore wind turbine farm and including a first arrangement that comprises:
a gearbox configured to mechanically convert a variable first rotational speed of a wind turbine into a higher variable second rotational speed; a generator having a rated electrical frequency for full-power output in a range from about 50 Hz to about 150 Hz, and configured to be driven at the variable second rotational speed by an output of the gearbox and to thereby generate electricity at a correspondingly variable first frequency; and an AC-to-AC converter configured to convert the electricity from the generator into electricity output from the AC-to-AC converter at a fixed low frequency for off-shore collection at the fixed low frequency, wherein the fixed low frequency is lower than a utility grid frequency.